TECHNICAL SPECIFICATION FOR A 1500V DC … · This document is the MTM technical specification for a indoor metal-clad 1500V DC n ... • busbar compartment ... TECHNICAL SPECIFICATION

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Engineering Specification Electrical

MESP 030000-01

TECHNICAL SPECIFICATION FOR A 1500V DC SWITCHGEAR

ASSEMBLY

Version: 2

Issued: October 2017

Owner: Chief Engineer

Approved By:

Phil Ellingworth

Chief Engineer

TECHNICAL SPECIFICATION FOR A 1500V DC SWITCHGEAR ASSEMBLY

MESP 030000-01 Version: 2 Effective from: 25th October 2017

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Approving Manager: Head of Engineering Electrical Approval Date: 25/10/2017 Next Review Date: 25/10/2020 PRINTOUT MAY NOT BE UP-TO-DATE; REFER TO METRO INTRANET FOR THE LATEST VERSION Page 2 of 32

Approval

Amendment Record

Approval Date Version Description

18/03/2014 1 Initial issue under MTM. Replaces MainCo document MESP0013.

25/10/2017 2

Corporate number changed from L2-ELN-SPE-004.

Restructured and revised throughout to emphasise required functionality over anticipated construction and improve alignment with standards. Arc fault containment requirements added.



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Table of Contents

1 Purpose ...................................................................................................................... 6

2 Scope.......................................................................................................................... 6

3 Abbreviations ............................................................................................................ 6

4 Definitions .................................................................................................................. 6

5 Standards ................................................................................................................... 7

6 Assembly Configuration ........................................................................................... 7

7 Cubicle Configuration ............................................................................................... 7

8 Operating Conditions ................................................................................................ 8

8.1 Service Conditions...................................................................................................... 8 8.2 Electrical Conditions ................................................................................................... 8

9 Ratings ....................................................................................................................... 9

10 Circuit Breaker ........................................................................................................... 9

10.1 Characteristics & Ratings ........................................................................................... 9 10.2 Arc Chute ................................................................................................................. 10 10.3 Auxiliary Contacts ..................................................................................................... 10 10.4 Overcurrent Releases ............................................................................................... 10 10.5 Operation ................................................................................................................. 10 10.6 Mechanical Indications ............................................................................................. 10

11 Bus Tie Disconnection Facility .............................................................................. 11

11.1 Application ................................................................................................................ 11 11.2 General .................................................................................................................... 11 11.3 Interlocking ............................................................................................................... 11 11.4 Auxiliary Contacts ..................................................................................................... 11

12 Switchgear or Link Trucks ...................................................................................... 11

12.1 General .................................................................................................................... 11 12.2 Truck Positions ......................................................................................................... 12 12.3 Truck Access & Interlocking ..................................................................................... 12 12.4 Truck Isolation .......................................................................................................... 12



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13 Power Cable Connection ........................................................................................ 12

13.1 General .................................................................................................................... 12 13.2 Terminal Requirements ............................................................................................ 13

14 Positive Busbar ....................................................................................................... 14

14.1 1500V Positive Busbar ............................................................................................. 14 14.2 Bus Measurement Transducers ................................................................................ 14

15 Negative Strip .......................................................................................................... 14

16 Short Circuiting Facilities ....................................................................................... 14

16.1 Line Short Circuiting Facility ..................................................................................... 14 16.2 Bus Short Circuiting Facility ...................................................................................... 15

16.2.1 Fixed Short Circuit Switch Requirements ................................................................ 15 16.2.2 Short Circuit Truck Requirements ........................................................................... 15

16.3 Short Circuiting Facility Requirements ...................................................................... 15 16.4 Short Circuit Switch Lighting ..................................................................................... 16

17 Control, Protection & Measurement ...................................................................... 16

17.1 General .................................................................................................................... 16 17.2 Indicating Lights ....................................................................................................... 17 17.3 Control Switches ...................................................................................................... 17 17.4 Rectifier Control System Integration ......................................................................... 17 17.5 SCADA Interface ...................................................................................................... 18 17.6 Feeder Protection & Measurement System .............................................................. 18

17.6.1 Protection Relay Requirements ............................................................................... 19

17.6.2 Measurement Transducers ...................................................................................... 19

17.6.3 Protection Functions ................................................................................................ 20

17.7 Contacts ................................................................................................................... 20 17.8 Wiring ....................................................................................................................... 21 17.9 Test Links ................................................................................................................. 21

18 Construction ............................................................................................................ 21

18.1 General .................................................................................................................... 21 18.2 Labelling ................................................................................................................... 22

19 Testing...................................................................................................................... 22

19.1 Type Tests ............................................................................................................... 22 19.1.1 Control Circuits Power Frequency Voltage Withstand ............................................ 23

19.1.2 Arc Containment Type Test ..................................................................................... 24



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19.2 Routine Tests ........................................................................................................... 24 19.3 Test Certificates ....................................................................................................... 24

20 Documentation and Support .................................................................................. 25

20.1 Collaboration ............................................................................................................ 25 20.2 Contract Documentation ........................................................................................... 25 20.3 Design Documentation ............................................................................................. 25 20.4 Delivery Documentation ........................................................................................... 25 20.5 Design Drawings ...................................................................................................... 26 20.6 Technical Maintenance Plan ..................................................................................... 26 20.7 Maintenance Manual ................................................................................................ 27 20.8 Installation Instruction Manual .................................................................................. 27 20.9 Operating Instructions Manual .................................................................................. 27 20.10 Training Material ....................................................................................................... 27 20.11 Tools & Equipment ................................................................................................... 27 20.12 Documentation Requirements .................................................................................. 28 20.13 Drawing Format ........................................................................................................ 28

21 Appendix A – Technical Data Schedule Form ...................................................... 28

21.1 Compliance .............................................................................................................. 28 21.2 General .................................................................................................................... 29 21.3 DCCB Cubicles ........................................................................................................ 30 21.4 Bus Tie Disconnection Cubicles ............................................................................... 30 21.5 Control Supply .......................................................................................................... 30 21.6 Protection System .................................................................................................... 30 21.7 DCCB ....................................................................................................................... 31 21.8 Bus Tie Disconnection Facility .................................................................................. 31 21.9 Short Circuit Switches .............................................................................................. 32

List of Tables Table 1: Cubicle Functionality ......................................................................................................... 7 Table 2: Assembly Ratings ............................................................................................................. 9 Table 3: Circuit Breaker Ratings ..................................................................................................... 9 Table 4: Circuit Breaker Auxiliary Contact Requirements .............................................................. 10 Table 5: Disconnection Ratings ..................................................................................................... 11 Table 6: Cable Connection Requirements ..................................................................................... 13 Table 7: Short Circuiting Facility Ratings ....................................................................................... 15 Table 8: Control & Protection Functionality ................................................................................... 16 Table 9: Drawing Requirements .................................................................................................... 26



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1 Purpose This document is the MTM technical specification for an indoor metal-clad 1500V DC switchgear assembly containing mechanical high speed DCCBs and disconnectors suitable for use in the MTM Electrical Network.

2 Scope This document applies to the supply of 1500V DC switchgear for use in new substation installations or for renewals of existing equipment on the MTM network.

3 Abbreviations ACCB - Alternating Current Circuit Breaker

CT - Current Transformer/Transducer

DCCB - Direct Current Circuit Breaker

Electrol - Electrical Systems Control Centre

MTM - Metro Trains Melbourne

SCADA - Supervisory Control and Data Acquisition

RTU - Remote Terminal Unit (of the SCADA system)

VT - Voltage Transformer/Transducer

4 Definitions For technical terms refer to BS EN 50123

Bus Tie DCCB means a High Speed Interconnector Circuit Breaker in conformance with BS EN 50123 (H/I)

Feeder DCCB means a High Speed Line Circuit Breaker in conformance with BS EN 50123 (H/L/U1)

High Voltage means (for the purposes of these procedures), a difference of potential normally existing between conductors and conductors and earth of 650V and above (AC or DC)

Rectifier DCCB means a High Speed Rectifier Circuit Breaker in conformance with BS EN 50123 (H/R/U1)

Shall is used as the descriptive word to express a requirement that is mandatory to achieve conformance to the standard.

Short-Circuit Switch is a fault-make switch used to connect a line or bus to negative.

Should is used as the descriptive word to express a requirement that is recommended in order to achieve compliance to the standard. should can also be used if a requirement is a design goal but not a mandatory requirement.



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5 Standards The assembly shall comply with BS EN 50123 - Railway Applications – Fixed Installations – DC Switchgear.

All materials and components shall comply with the relevant Australian Standard or, where these do not exist, shall comply with the relevant IEC or EN standard.

Reference to all standards shall be read as a reference to the latest edition of that standard and amendments available at the time of tendering.

6 Assembly Configuration The switchgear assembly shall consist of a number of Feeder DCCB, Rectifier DCCB, Bus-Tie DCCB, and Bus-Tie DC Disconnection cubicles.

The number of each type of cubicle in an assembly is dependent on the site configuration and will be described in a specific scope of works document.

7 Cubicle Configuration Each cubicle shall be self-supporting, floor mounted, and metal-clad, containing all of the components necessary for the proper operation of the equipment.

Each cubicle shall contain at least the four following metallically partitioned compartments:

• switchgear compartment

• control compartment

• busbar compartment

• power cable connection compartment

The functionality required within each cubicle is dependent upon the type of cubicle and is shown in the table below:

Table 1: Cubicle Functionality

Feeder DCCB Cubicle

Rectifier DCCB Cubicle

Bus Tie DCCB Cubicle

Bus Tie DC Disconnection

Cubicle Withdrawable DCCB

Bus Tie Disconnection Facility

Positive Busbar Power Cable Connection

Line Short Circuiting Facility Preferred

Control, Protection & System

A bus voltage transducer and busbar short circuiting facility shall be provided for each assembly. These may either be provided in a dedicated cubicle, or within a single Feeder DCCB cubicle, designated the ‘Master Feeder’.



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8 Operating Conditions

8.1 Service Conditions The Assembly will be installed indoors in a railway traction substation or tie station building.

The normal indoor service conditions as detailed in Clause 4 of BS EN 50123-1:2003 shall apply, except that the absolute maximum ambient temperature (Θa) shall be taken to be 45°C. The nominated performance of all components and devices shall be guaranteed at this ambient temperature.

8.2 Electrical Conditions The Assembly will be used to supply 1500V DC power to trains on the MTM network. This electrical network consists of traction substations and tie-stations and a 1500V DC overhead contact wire distribution system.

The substations contain rectifier units with continuous power ratings of between 1.5MW and 4.0MW.

The voltage of the 1500V DC network at the substations and tie-stations typically varies between 1000V DC and 1800V DC.

The overhead contact wire distribution system typically consists of sections between 2 and 5 km in length. It is susceptible to lightning and short-circuits, typical of this type of construction and use.

The maximum prospective fault current of the 1500V DC network adjacent to a substation is typically in the range of 30,000 A to 120,000 A. The time constant of the fault current is generally in the range of 5 to 20 milliseconds.

The maximum prospective fault current through the Feeder DCCBs for a fault at the distant end of an overhead section is typically in the range of 3,000 A to 15,000 A with a time constant of 15 to 50 milliseconds.

The assembly enclosure will typically be electrically insulated from the floor, and connected to the substation 1500V DC negative bus at a minimum of two points. Alternatively it may be insulated from the floor and connected to the substation earth via a single frame leakage relay for the assembly.



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9 Ratings The assembly shall comply with the following minimum ratings:

Table 2: Assembly Ratings Rating Requirement

Nominal Voltage 1,500V Service Current ≥4,000A

Overload Duty Cycle 200% for 1 minute, preceded and followed by 100% continuously

Insulation Voltage ≥3,000V Power Frequency Withstand ≥9,200V at 50Hz Impulse Withstand Voltage ≥20,000V

Power Frequency Withstand across an isolation ≥11,000V at 50Hz

Impulse Withstand Voltage across an isolation ≥24,000V

Control Voltage 48V DC (preferred), 110V DC or 125V DC Minimum clearance between

positive and negative conductors ≥36mm

Minimum clearance between positive conductor and frame ≥36mm

Minimum clearance between negative conductor and frame ≥36mm

The assembly shall be arc fault contained – it shall attain IAC AFLR in accordance with AS 62271.200. The internal arc shall be 125kA for 0.25s.

10 Circuit Breaker

10.1 Characteristics & Ratings The DCCB shall be a single pole high-speed current limiting circuit breaker which shall comply with BS EN 50123-2. The interrupting medium shall be air.

The DCCB shall be trip-free and fail-safe. It shall be withdrawable and truck mounted (refer section 11 for requirements), located within the switchgear compartment.

The DCCB shall comply with the following ratings:

Table 3: Circuit Breaker Ratings Rating Requirement

Maximum Arc Voltage ≤6,000V Rated Short Circuit Current 125 kA Rated Track Time Constant 63ms

Mechanical Endurance without replacement of parts ≥20,000 operations

Test Duty Cycle Duty 2



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10.2 Arc Chute The arc chute of the DCCB shall be mounted on the circuit breaker. It shall be attached to the circuit breaker with hinges for ease of inspection and maintenance.

The arc chute shall be able to be lifted/opened easily for inspection or maintenance by one person without any special tools or lifting devices and without removal of any other parts of the DCCB or its truck.

10.3 Auxiliary Contacts The following number of voltage free auxiliary contacts shall be provided on the respective circuit breakers, in addition to those required for operation and local indication.

Table 4: Circuit Breaker Auxiliary Contact Requirements

Circuit Breaker Type No. Of Auxiliary Contacts

Normally Open Normally Closed

Feeder DCCB 3 3

Rectifier DCCB 6 6

Bus-Tie DCCB 3 3

10.4 Overcurrent Releases Feeder DCCBs shall be fitted with a direct acting series overcurrent release which shall be uni-directional, operating on current flowing away from the busbar, towards the load. The release shall have a setting range between 3,000 and 8,000 amperes in 500 ampere steps.

Rectifier DCCBs shall automatically trip by a uni-directional direct acting series overcurrent release. The uni-directional release shall operate on a current flowing away from the busbar, towards the rectifier. The release shall have a single setting which shall be as low as practicable and shall not exceed 2,000 amperes.

Bus-Tie DCCBs do not require a direct acting overcurrent release.

10.5 Operation The DCCB shall be able to be manually and electrically opened and shall be able to be electrically closed.

The manual opening of the DCCB shall be performed from the front of the cubicle with all doors closed and shall be achieved by depressing a trip button coloured red.

10.6 Mechanical Indications A mechanical indication of the open/closed status of the DCCB and the truck position shall be visible from the front of the cubicle at a reasonable height above floor level.



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11 Bus Tie Disconnection Facility

11.1 Application The disconnection facility is provided within the switchgear compartment for connecting multiple 1500V DC buses together. On one busbar, a bus tie DCCB will be provided, and on the other, a bus tie disconnection facility, with a cable connection between the two.

11.2 General The bus tie disconnection facility shall be comprised either of a withdrawable link truck or a fixed mounted single pole DC Disconnector.

Fixed disconnectors shall be able to be manually operated from the front of the cubicle with the compartment door closed.

The disconnection shall comply with the rated values shown in Table 5.

Table 5: Disconnection Ratings Rating Requirement

Service Current ≥4,000A Minimum Clearance Across Isolation ≥43mm

11.3 Interlocking The bus tie disconnection facility shall be either electrically or key interlocked with its corresponding bus tie DCCB to prevent it being used to make or break current.

11.4 Auxiliary Contacts There shall be 3 normally open and 3 normally closed voltage free auxiliary contacts provided on the disconnection facility, in addition to those required for local indication.

12 Switchgear or Link Trucks

12.1 General Trucks shall be provided for DCCBs and may be used for bus tie disconnection facilities and/or bus short circuiting facilities. The trucks shall be inserted into the switchgear compartment. Each truck shall be provided with ergonomically designed and positioned handles for positioning and moving.

All trucks of the same type shall be interchangeable. Trucks of different types shall not be interchangeable, e.g. a Rectifier DCCB truck shall not be able to be inserted into a Feeder DCCB cubicle.

Trucks shall be clearly marked with their type in accordance with MESP 000003-04 Substation Signage and Labelling.



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12.2 Truck Positions The truck shall have three positions: the service position, the test position and the disconnected position.

In the test position, only the power circuit shall be disconnected to permit off-load testing of the DCCB and the control and protection system.

In the disconnected position, the truck may be removed completely from its compartment and the control circuitry shall also be disconnected.

12.3 Truck Access & Interlocking The switchgear compartment shall be provided with an interlocked front door. Alternatively the compartment door may be integrated into the truck.

The interlock shall prevent movement of the truck or opening of the door if the DCCB is not open and prevent the DCCB from closing when not properly positioned in the service, test or disconnected position.

The compartment shall be provided with automatic shutters to separate the compartment from the busbar and the power cable connection when the truck is not in the service position. The shutters shall be made of a transparent insulating material to allow a visual inspection of the fixed contacts. The shutters shall be lockable in the closed position using a safety padlock, which shall prevent a truck from being racked in.

It shall be possible to place a padlock to prevent a truck being placed into the service position.

12.4 Truck Isolation In both the test and disconnected positions, an isolation shall be provided between the DCCB and both the bus and the line, and between the bus and the line. Both the bus and line shutters shall be closed. The power frequency withstand across the isolation shall be a minimum of 11,000V at 50Hz and the impulse withstand voltage shall be a minimum of 24,000V.

13 Power Cable Connection

13.1 General The power cable connection facilities shall be provided within the power cable connection compartment.

It shall be possible for the power cable to enter the cubicle from below or above the assembly.

The compartment shall contain a facility for the connection of cable screens to the negative bus.



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13.2 Terminal Requirements The terminal shall be suitable for the termination of the following number of power cables:

Table 6: Cable Connection Requirements Cubicle Type No. of Cables

Feeder DCCB 6 Rectifier DCCB 8 Bus-Tie DCCB 8 Bus-Tie DC Disconnection 8

The standard type of cable used is 500 mm² aluminium conductor, 3.8/6.6 kV XLPE insulated, 90 mm² copper screened and PVC/HDPE sheathed cable, terminated with appropriate cable lugs.

The cables may be connected back to back. Holes shall be drilled in the terminal suitable for connection of lugs as shown in Figure 1 below.

Figure 1: Cable Lug

An allowance of 400 mm length to a gland or cable support should be made for the cable termination. Appropriate brackets and clamps shall be provided to adequately support the cables in the compartment so that the weight of the conductor is not taken by the terminal or lug.

Sufficient clearance shall be provided between the cable screens and positive conductors, and between cable screens and the switchgear frame such that the minimum clearance distance of 36mm as specified in Table 2 is not compromised, allowing for installation tolerances.

20mm 50mm

>70mm

14mmØ



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14 Positive Busbar

14.1 1500V Positive Busbar Each cubicle shall contain a single busbar, mounted in the busbar compartment.

The busbar shall be designed to facilitate simple connections between any two adjacent cubicles.

14.2 Bus Measurement Transducers A bus voltage transducer (VT) shall be provided in the busbar compartment of one cubicle per bus, for connection to protection and measurement systems.

The VT should be accessible from the front of the cubicle.

15 Negative Strip A negative strip shall be provided through the assembly in the power cable connection compartments. It shall be insulated from the cubicle frame but provided with facility for connection in each cubicle.

The negative strip shall be able to be simply connected or disconnected to adjacent cubicles at the cubicle edges, similarly to the positive busbar. It shall be painted mid blue in accordance with AS 2700S:2011 (B15).

The negative strip shall be of a minimum cross sectional area of 185mm2 and shall be capable of carrying 125kA fault current for 0.25s.

The negative strip shall be constructed so as to facilitate the connection of cable screens to the strip without any modification required.

16 Short Circuiting Facilities

16.1 Line Short Circuiting Facility A fault make short circuiting facility shall be provided to short circuit the line/power cable connection in each DCCB cubicle. This shall be provided in the form of a fixed fault make short circuit switch or other fixed fault make arrangement, complying with the requirements in section 16.3.

Interlocking shall be provided to ensure that it is impossible to apply a short circuit when the line is not isolated from the bus. It shall not be possible to remove the isolation between bus and line while the short circuit is applied.

On Feeder DCCBs, the short circuiting facility shall be electrically interlocked to prevent the application of a short circuit onto a live line.

The short circuit shall be able to be manually applied and removed locally. It shall be possible to utilise a safety padlock to prevent the short circuit being removed.

It shall be possible to remotely electrically short circuit the line on Feeder DCCB cubicles through one or more control operations. It shall be possible to remotely electrically remove the short circuit.



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16.2 Bus Short Circuiting Facility A fault-make busbar short-circuiting facility shall be provided for the assembly.

This facility should be fixed mounted switch in a dedicated compartment in accordance with section 16.2.1, however a Bus Short Circuiting Truck which can rack into a Feeder DCCB cubicle (in place of the circuit breaker truck) may be acceptable in accordance with section 16.2.2. The facility shall comply with the requirements in section 16.3.

The short circuit shall be able to be manually applied and removed locally. It shall be possible to utilise a safety padlock to prevent the short circuit being removed.

16.2.1 Fixed Short Circuit Switch Requirements The short circuit switch shall be interlocked with all DCCB trucks and disconnectors on the bus.

It shall only be able to be closed when all trucks are in the test or disconnected position and all disconnectors are locked in the open position.

It shall not be possible to move any trucks to the service position or to close a disconnector when the bus short circuit switch is closed.

16.2.2 Short Circuit Truck Requirements The short circuit switch shall be interlocked with its truck, and shall only be able to be racked into and out of the service position with the short circuit switch open.

The truck shall be painted red and labelled “Bus Short Circuiting Switch”.

16.3 Short Circuiting Facility Requirements The short circuiting facility shall achieve the ratings specified in Table 7:

Table 7: Short Circuiting Facility Ratings Rating Line Short Circuiting Bus Short Circuiting

Rated Making Capacity ≥50kA ≥125kA Rated Short Time Withstand Current ≥50kA for 0.1s ≥125kA for 0.25s

It should be possible to directly view the contacts required to make the short circuit from the front of the assembly.

Where the contacts are not visible from the front of the cubicle, mechanical semaphores shall be provided at the front of the cubicle.

Where the contacts are directly visible, but not easily able to be viewed using only ambient light, internal lighting shall be provided in accordance with section 16.4.

Where a mechanical semaphore is provided, it shall be connected to the contacts by a direct and simple mechanical linkage.



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16.4 Short Circuit Switch Lighting The illumination shall be provided by a double insulated non-metallic light fitted to the compartment.

The light shall be able to be switched from outside the cubicle and should operate on a timer. A single switch may be provided on the assembly to switch all of the illumination lights.

17 Control, Protection & Measurement

17.1 General Each cubicle shall include a control system. The control system components shall be located so far as practicable within the control compartment at the front of the cubicle. Access to the compartment shall be by a hinged, dustproof door with a non-locking handle.

The following components shall be located or viewed from the front of the compartment:

• Control Switch (Device 72CS)

• Indicating Lights

• C & I Isolating Switch (Device 230) or Local/Remote Switch (Device 72LR)

• Protection Relay (Device 76)

All other equipment shall be mounted inside the compartment.

The control system shall be designed such that all external connections (for example, to the substation battery or SCADA system) are isolated or insulated to 2kV from the switchgear frame. All connections to high voltage equipment shall be insulated to 2kV from both the positive and negative conductors.

The control system should be provided using relay logic - the use of PLCs is not preferred.

The functionality required for each cubicle is described in Table 8 below.

Table 8: Control & Protection Functionality

Feeder DCCB

Cubicle

Rectifier DCCB

Cubicle

Bus Tie DCCB

Cubicle

Bus Tie DC Disconnection

Cubicle Indicating Lamps

Control Switches Rectifier Control

System Integration

SCADA Interface

Feeder Protection & Measurement System



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17.2 Indicating Lights Indicating lights shall be provided to indicate:

• Open (green) and Closed (red) position of the DCCB or DC Disconnector,

• Line Short Circuited (blue),

• Line Alive (red), and

• Bus Alive (red) (one per bus).

They shall be provided by long life, high reliability, and replaceable LED lights.

A lamp test facility shall be provided. A single pushbutton should be provided for testing all lights in the assembly.

The open and closed indications of the DCCB and DC Disconnector shall be provided using dedicated auxiliary contacts.

17.3 Control Switches Each DCCB shall be locally controlled by a control switch on the compartment door. It shall be a spring return to neutral type with a pistol grip handle. The two positions shall be labelled “Trip” and “Close”. The switch shall be turned anticlockwise to trip and clockwise to close.

For Feeder and Bus Tie DCCBs, a two position C & I Isolating Switch with a yellow escutcheon shall be provided to isolate the control and indication functions (by breaking the common) of the DCCB and DC Disconnector from the RTU. The switch shall also isolate the control function of the line short circuiting facility. The switch positions shall be labelled “Isolated” and “Normal”.

For Rectifier DCCBs, a two position Local/Remote Switch shall be provided to enable or disable operation of the DCCB as a slave of the corresponding Rectifier ACCB. In the Remote position, the local control switch shall be disabled, and in the Local position, remote control shall be disabled.

17.4 Rectifier Control System Integration The Rectifier DCCB shall act as a slave of the Rectifier ACCB. The Rectifier DCCB shall be closed by the successful closing of the Rectifier ACCB and opened by the opening of the Rectifier ACCB. It shall be provided with a single normally open auxiliary contact of the Rectifier ACCB to achieve this functionality.

Tripping of the Rectifier DCCB via its direct acting overcurrent release shall cause lockout of the rectifier unit. This functionality shall be provided by the Rectifier Unit Control System via an auxiliary contact, in accordance with MESP 020500-01 Technical Specification for a Rectifier Unit Control & Protection System for use in the 1500V DC Traction System.



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17.5 SCADA Interface Each cubicle shall include a SCADA interface. All points that are to be controlled by or indicated to the SCADA system shall be connected by a 3-wire system in accordance with MESP 081000-01 Technical Specification for SCADA Cabling in Substations

Each point to be controlled shall be operated via interposing relays. The relay coils of each controlled point shall be connected to an independent common. The current consumption of the Interposing Relay coil shall be 60 - 100 mA at the Control Voltage. The SCADA RTU provides a 1 second duration pulse to the Interposing Relay.

Hardwired indications shall be provided as pairs of voltage free contacts, such that failure is indicated by an invalid combination. Each point shall have its own independent common connection

Each point that is both controlled and indicated shall be brought to sequential terminals on a terminal strip.

The following indications must be provided as hard wired points:

• DCCB or Disconnector position

• Line Short Circuit Switch position

• Line Alive

• Protection Relay Healthy

• Bus Alive

• Bus Short Circuit Switch position (if fixed)

17.6 Feeder Protection & Measurement System Each of the Feeder DCCB Cubicles shall be provided with a measurement and protection system. This system shall comply with EN 50123-7: Measurement, Control and Protection of DC Traction Systems - Section 1: Application Guide.

The system shall be microprocessor based, and shall have a user-friendly interface. It shall provide line current and line voltage measurements, and the protection functions listed in section 17.6.3.

Since there is no backup protection provided, the system shall be failsafe. Failure of any of the following shall cause the DCCB to trip:

• Loss of control supply

• Failure of protection relay

• Failure of CTs or VTs



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17.6.1 Protection Relay Requirements The protection relay shall be a digital multifunction DC protection relay with multiple, selectable setting groups. As a minimum, the protection functionality described in section 17.6.3 shall be provided, with each function able to be selected to either provide a trip or an alarm.

It shall have a self-testing watchdog function, which shall provide an alarm if there is a failure of the system or any of its component functions, including a loss of connection to the measurement transducers. Failure of any critical part of the system shall cause tripping of the DCCB.

The relay shall permanently record the number of each type of trip given to the DCCB. The most recent trips (minimum 20) shall be recorded together with the measured voltages and currents at the time of tripping.

The relay shall provide oscillographic recordings, able to be configured to trigger from any combination of the protection functions provided. The recordings shall include the value of all analogue measurements and digital inputs and outputs. The relay shall store a minimum of 10 recordings of 0.3 seconds each in duration.

The relay shall have an integrated display and use a plain language menu system. The display shall provide indications of the current line current and voltage measurements, and allow for viewing of the most recent events and alarms. It shall be possible to enable and disable protection functions and alter protection settings from the integrated display.

Software and an appropriate interface shall be provided for interacting with the protection relay from a computer. Software and access shall be provided for MTM to make changes to all settings and configure the protection system as required. It shall be possible to view all data and view or modify all settings within the protection relay from the software provided.

The relay shall communicate with the SCADA RTU using a suitable protocol over a serial or Ethernet interface over optic fibre. The preferred protocol is DNP3. It shall be possible to remotely set the relay’s clock via the SCADA communication protocol.

The following indications shall be provided as soft points as a minimum:

• Line voltage

• Line current

• Bus voltage

17.6.2 Measurement Transducers Current and Voltage Transducers shall be provided for connection to protection and measurement systems. These shall comply with EN 50123-7, sections 2 and 3 respectively.

The Line CTs and VTs should be located on the DCCB truck to facilitate ease of access and maintenance. Where CTs and VTs are located within the cubicle, they shall not be located within the busbar or control compartments. It shall be possible to easily access VT fuses from the front of the cubicle.

The CTs and VTs shall be isolated to a minimum of 9kV from associated measurement and protection devices.



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17.6.3 Protection Functions The protection functions provided by the protection relay in addition to the direct acting releases on the DCCBs shall include the following as a minimum:

Uni-Directional Falling Voltage Overcurrent / Instantaneous Impedance Trip The uni-directional falling voltage overcurrent characteristic images the resistance of the overhead network section. It shall be possible to set a section resistance (R) and arc voltage (Va) and have the relay issue a trip command instantaneously where 𝑅𝑅 ≤ 𝑉𝑉−𝑉𝑉𝑎𝑎

𝐼𝐼.

1500V DC Under-Voltage Release The 1500V DC under-voltage release shall cause a trip when the bus and line voltages drop below a set value. The setting shall be adjustable between 100V and 800V and should have a hysteresis characteristic. It shall be failsafe.

Thermal Overload The thermal overload setting is an inverse-time overcurrent characteristic that images the thermal characteristics of the overhead wiring.

The characteristics of the thermal curve shall be adjustable.

Rate of Rise (di/dt) and ΔI Protection The protection functionality described in Annex B of EN 50123-7-1:2003 shall be available within the protection relay.

Control Voltage Under-Voltage Release The control voltage under-voltage release shall trip when the control voltage is insufficient to guarantee the correct operation of the circuit breaker and the measurement and protection system. It shall be failsafe.

Circuit Breaker Failure The system shall have a function that checks the resultant opening of the DCCB. If the DCCB does not open, a backup tripping system shall be initiated. This may involve other DCCBs.

Automatic Reclosure An automatic reclosure function shall be provided for Feeder DCCBs that should operate when both the bus voltage and line voltage are normal after an automatic trip, provided there has not been a control trip. The function shall be able to be switched on and off by the SCADA System.

17.7 Contacts All auxiliary contacts of switchgear and contacts of control relays for connection to external devices shall be suitable for carrying 20A and breaking 5A at the control voltage.



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17.8 Wiring All conductors used for control voltage secondary wiring shall be stranded and have a cross sectional area of not less than 1.5 mm².

A system of permanent labelling for identification of all cables shall be used in accordance with MESP 000003-04. The label shall appear on each end of each wire. The label shall be securely attached to the cables and be easily readable.

The control and auxiliary terminations for connection to external circuits shall be provided at a convenient and accessible position inside the Control Compartment.

17.9 Test Links Test links shall be provided to facilitate testing of the control, protection and measurement system. The preferred test link types are Phoenix URTK/S slide links or Weidmüller WT series test terminals.

As a minimum, test links shall be provided for all inputs/outputs of the protection relay.

Links shall be mounted such that the field/primary system/earth connection is physically located on the right side, or the bottom side of the terminal rail. The device/secondary connection shall be located on the top or left side. Slide links shall be opened by sliding towards the top or left.

18 Construction

18.1 General The assembly shall be constructed in such a manner that any cubicle can be removed from the assembly, and in particular, if an internal arcing fault develops inside a cubicle it shall not damage the adjacent cubicles and shall not prevent the cubicle from being subsequently removed.

The assembly shall be as compact as possible. It is desirable that the switchgear is constructed such that all installation and maintenance tasks are able to be completed from the front of the cubicle.

The assembly shall provide a minimum ingress protection of IP 21 in accordance with AS 60529 on all accessible faces, with the circuit breaker trucks in any position. The top of the switchgear shall be constructed so as to prevent the ingress of dust – a horizontally mounted mesh shall not be used.

All metalwork shall be suitably prepared and painted to protect it against corrosion for the expected life of the equipment. The method shall be submitted and shall be approved in writing. The external colour shall be mid blue in accordance with AS 2700S:2011 (B15).

Where provision is made for padlocks, the holes for the padlocks shall be 10 mm in diameter.

A lifting facility shall be provided for each cubicle.

The entire assembly (including all trucks, interrupters and cubicles) shall contain no asbestos or materials containing asbestos fibres. A statement certifying that the product is free of asbestos containing materials must be completed and signed, and shall be delivered to MTM prior to despatch.



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18.2 Labelling All cubicles, compartments, control switches, components and indicators shall be labelled in accordance with MESP 000003-04 Substation Signage and Labelling and have appropriate warning signs. The external labels shall be of the Traffolyte type and shall be fastened by screws.

Each cubicle will be assigned a section number as part of the 1500V DC traction supply system.

19 Testing

19.1 Type Tests The Feeder, Rectifier and Bus-Tie DCCBs, Bus Tie Disconnection Facilities, and Short Circuiting Facilities shall have type test certificates complying with BS EN 50123. The tests shall be performed with the device in its cubicle and all power cables connected. The certificates shall include oscillograms and drawings of the test circuit. Copies of these certificates shall be supplied with the tender documentation.

The following type test certificates shall be provided as a minimum:

• DCCBs:

o Verification of conformity (clause 8.3.1 of EN 50123-2),

o Mechanical operation (clause 8.3.2 of EN 50123-2),

o Impulse withstand voltage (clause 8.3.3.2 of EN 50123-2),

o Power frequency withstand voltage (clause 8.3.3.3 of EN 50123-2),

o Temperature rise (clause 8.3.4 of EN 50123-2),

o Electrical endurance (clause 8.3.6 of EN 50123-2),

o Mechanical endurance (clause 8.3.7 of EN 50123-2),

o Verification of DCCB making and breaking characteristics (clause 8.3.8 of EN 50123-2),

o Verification of short time withstand current of rectifier DCCB (clause 8.3.9 of EN 50123-2),

o Verification of behaviour under short time withstand current (clause 8.3.9 of EN 50123-2),

o Verification of the adjustment of relays and releases (clause 8.3.5 of EN 50123-2), and

o Search for critical currents and low current test duty (clause 8.3.10 of en50123-2).

• Fixed Disconnectors and Short Circuit Switches






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o Power frequency withstand voltage (clause 8.3.3.3 of EN 50123-3),

o Temperature rise (clause 8.3.4 of EN 50123-3, for fixed disconnectors only),

o Mechanical endurance (clause 8.3.6 of EN 50123-3),

o Verification of behaviour under short time withstand current (clause 8.3.8 of EN 50123-3), and

o Verification of the sturdiness of manual control device and reliability of position indicator (clause 8.3.9 of EN 50123-3).

• Short Circuiting Facilities:

o Verification of the rated making and breaking capacities (clause 8.3.7 of EN 50123-3),

o Verification of behaviour under short time withstand current (clause 8.3.8 of EN 50123-3), and

o Verification of the reliability of position indicator (clause 8.3.9 of EN 50123-3).

• Assembly:


o Operation (clause 8.3.2 of EN 50123-6),


o Main circuits power frequency voltage withstand (clause 8.3.3.3 of EN 50123-6),

o Control circuits power frequency voltage withstand (refer section 19.1.1),

o Short time withstand current – main circuits (clause 8.3.4.1 of EN 50123-6),

o Short time withstand current – busbars (clause 8.3.4.2 of EN 50123-6),

o Short time withstand current – earthing circuits (clause 8.3.4.3 of EN 50123-6),


o Verification of degree of protection (clause 8.3.6 of EN 50123-6),

o Temperature rise (clause 8.3.7 of EN 50123-6),

o Electrical operation (clause 8.3.8 of EN 50123-6), and

o Arc containment (refer section 19.1.2).

19.1.1 Control Circuits Power Frequency Voltage Withstand Tests shall be conducted generally in accordance with clause 8.3.3.3 of EN 50123-2, with the voltage applied between the control wiring, and the positive and negative busbars and cubicle frame. A minimum voltage of 2kV shall be applied for 60s.



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19.1.2 Arc Containment Type Test Type testing shall be conducted in accordance with Annex A of AS 62271.200:2005. Tests shall be conducted with the control compartment door open. The test current shall be DC.

Access shall be AFLR, that is, authorised persons only, to the front, rear and sides of the assembly.

19.2 Routine Tests The assembly shall be subjected to routine tests at the manufacturer’s workshop complying with EN 50123, which shall include the following tests as a minimum:

• DCCBs:



o Power frequency withstand voltage (clause 8.3.3.3 of EN 50123-2), and

o Verification of the adjustment of relays and releases (clause 8.3.5 of EN 50123-2).

• Fixed Disconnectors and Short Circuit Switches


o Mechanical operation (clause 8.3.2 of EN 50123-3), and

o Power frequency withstand voltage (clause 8.3.3.3 of EN 50123-3).

• Assembly:


o Operation (clause 8.3.2 of EN 50123-6),

o Main circuits power frequency voltage withstand (clause 8.3.3.3 of EN 50123-6), and

o Control circuits power frequency voltage withstand (refer section 19.1.1).

The Control, Protection and Measurement System shall be tested in accordance with a test plan approved by MTM.

MTM reserves the right to appoint a representative to witness these tests. Seven working days’ notification shall be given to MTM of intention to carry out routine testing.

A chart of the direct acting series overcurrent release calibration charts for the full range of all settings shall be provided for every DCCB. A calibration chart showing the full range of settings shall be provided in a suitable location on the DCCB truck.

19.3 Test Certificates The results of all tests shall be recorded on test certificates. The test certificates shall clearly show the performance of the equipment and shall be accompanied by tables showing the actually measured values and all calculations.

The routine test certificates shall be forwarded to MTM and the results approved by MTM prior to delivery.



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20 Documentation and Support

20.1 Collaboration The manufacturer should work collaboratively with MTM to refine and further develop their product to meet MTM’s unique requirements.

20.2 Contract Documentation One set of PDF copies of the drawings and documentation described in sections 20.5 and 20.8 should be provided for review and approval by MTM approximately 4 weeks after the contract award date.

No manufacture shall commence until the drawings have been approved. An allowance of ten working days should be made by the supplier for the review of submitted drawings

20.3 Design Documentation A hard copy and a soft copy of the following documentation shall be provided to MTM for every design of switchgear cubicle produced at the conclusion of design, and prior to delivery of the switchgear:

• Technical Maintenance Plan

• Maintenance Manual

• Installation Instruction Manual

• Operating Instruction Manual

• Storage, handling, loading and off-loading instructions

• Approved drawings

• Training Material

Whenever a design change is made, new copies of the updated design documentation shall be provided to MTM.

20.4 Delivery Documentation Each delivery shall include a hard copy of the following documents:

• Technical Maintenance Plan

• Maintenance Manual

• Installation Instruction Manual

• Operating Instruction Manual

• Storage, handling, loading and off-loading instructions

• Test Certificates

• Approved drawings

In addition, a soft copy of the test certificates shall be forwarded to MTM.



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20.5 Design Drawings The drawings described in Table 9 shall be provided to MTM at the nominated design stages for review, and at the completion of design.

Table 9: Drawing Requirements

Drawing Concept / Tender

Preliminary Design

Detailed Design

Construction details of the Assembly including dimensions.

Physical layout and arrangement of the components of the Assembly.

Physical layout and arrangement of the DCCB and Disconnection Cubicles.

Physical layout and arrangement of the Short-Circuit Facilities.

The interlocking arrangement of the Trucks, DCCBs, Disconnectors and Short-Circuit Switches.

Mounting requirements for the Assemblies.

Control circuit diagrams of each Cubicle.

Physical layout and arrangement of the Power Cable Connections.

Details of control and auxiliary wiring terminations.

Details of the 1500V DC Negative strip.

Details of manual operation of the equipment and any tools to be provided.

All other drawings required for Installation, Testing, Commissioning, Operation and Maintenance

20.6 Technical Maintenance Plan A Technical Maintenance Plan which establishes the maintenance policy for the Assembly recommended by the supplier shall be provided. This shall detail the preventative servicing schedules and maintenance intervals for all components of the Transformer. The servicing schedules shall reference appropriate detailed instructions in the maintenance manual.

The Technical Maintenance Plan shall contain a list of any spare parts, suppliers, indicative pricing, lead times and recommended spares holdings.

The Technical Maintenance Plan shall detail safe disposal procedures applicable for when the Assembly is no longer serviceable (recycling, hazardous waste etc.).



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20.7 Maintenance Manual A Maintenance Manual shall be provided which shall detail:

• The theory of operation of the equipment.

• All servicing activities.

• Overhaul instructions.

• Adjustment procedures.

• The changing of components for repairs.

• Fault-finding procedures.

• The spares support schedule.

The maintenance manual shall also include a complete set of as-built drawings and a comprehensive parts list for the Assembly.

The maintenance manual shall include an instruction manual of the Control, Protection and Measurement System which details all of the viewing, setting, modification of settings, the viewing of currents and the recording of events and alarms.

20.8 Installation Instruction Manual An Installation Instruction Manual shall be provided

The instructions shall enable the assembly to be properly installed, tested and commissioned. This shall include all necessary drawings.

20.9 Operating Instructions Manual An Operating Instruction Manual shall be provided which shall clearly describe the required procedures for physically operating all of the components of the Assembly.

The operating procedures shall be consistent with MTM’s requirements.

20.10 Training Material An operator training package and a maintainer training package shall be provided for the switchgear including the necessary audio-visual resources and suitable packages of the relevant information. The supplier shall provide training to MTM’s nominated trainers.

20.11 Tools & Equipment A complete set of operating tools and any other equipment necessary to operate and maintain the assembly shall be provided with each assembly. This shall include any special device required to test the assembly. Storage facilities for the tools and equipment shall also be provided.

The software and a PC interface for loading and downloading of settings and the latest fault current data to a laptop PC shall be provided. This shall include all peripheral interfacing equipment and connection cables necessary to connect and communicate with the system.

Any special lifting and installation equipment shall be supplied with the assembly.



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20.12 Documentation Requirements All documentation shall be provided in English.

Every page of the documentation shall be clearly identified in relation to the document to which it belongs and the version of that document. All pages of multi-page documents shall be uniquely numbered. It shall be possible to readily determine if all pages of a document are present.

Manuals shall be A4 size and shall be bound in durable covers or in 4-D ring binders.

Electronic copies of the Maintenance Manual, Installation Instructions Manual and Operating Instructions shall be provided in both PDF and Microsoft Word formats.

20.13 Drawing Format All drawings shall comply with PTV Infrastructure Drafting Standard and shall be submitted for MTM approval prior to manufacturing.

Drawings shall be provided in Microstation format and PDF.

One electronic and a minimum of two paper copies of the each document shall be provided and the content shall be identical in each copy.

21 Appendix A – Technical Data Schedule Form The Tenderer shall supply the following information and guaranteed performance thereof.

21.1 Compliance a. Does the Assembly fully comply with this Specification? YES / NO

b. If not, has a list of non-compliances with justifications been provided? YES / NO

c. Are type test certificates attached, including oscillograms? YES / NO

d. Are general arrangement drawings attached, clearly showing the overall dimensions of the assembly and each cubicle, and details of the YES /NO proposed cable terminals and cable entry requirements?

e. Are preliminary control circuit drawings attached? YES / NO

f. Have relevant pamphlets and technical information for the DCCB been attached? YES / NO

g. Have relevant pamphlets and technical information for the protection system been attached? YES / NO

h. Is an analysis of the mean time between failures (MTBF) causing the unavailability of failure of a Feeder DCCB cubicle including an analysis YES / NO to the component/device level attached?

i. Is a list of recommended spare parts, holdings and costs attached? YES / NO

j. Is an explanation of the interlocking and padlocking facilities included? YES / NO



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21.2 General a. Rated Operating Voltage (V DC) ………………………… b. Rated Insulation Voltage (V DC) ………………………… c. Rated Power Frequency Withstand Voltage (1 min)

(kV RMS) ………………………… d. Rated Impulse Voltage (kV peak) ………………………… e. Rated continuous busbar current (A DC) ………………………… f. Cross sectional area of negative strip (mm2) ………………………… g. List of metal clad compartments in each Cubicle: …………………………

………………………… ………………………… ………………………… …………………………

h. MTBF for Feeder DCCB (years) ………………………… i. Maximum acceptable deviation from flatness of floor

(mm in 1m) ………………………… j. Minimum clearance positive to negative (mm) ………………………… k. Minimum clearance positive to frame (mm) ………………………… l. Minimum clearance negative to frame (mm) ………………………… m. Minimum clearance across an isolation (mm) ………………………… n. Cubicle ingress protection rating …………………………



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21.3 DCCB Cubicles a. Overall dimensions of Cubicle:

i. Height (mm) ………………………… ii. Width (mm) ………………………… iii. Depth (mm) …………………………

b. Weight, fully equipped including truck (kg) ………………………… c. Weight of DCCB truck (kg) ………………………… d. Clearance above cubicle for air ventilation (mm) ………………………… e. Clearance required in front of cubicle (mm) ………………………… f. Clearance required behind cubicle (mm) …………………………

21.4 Bus Tie Disconnection Cubicles a. Overall dimensions of Cubicle:

i. Height (mm) ………………………… ii. Width (mm) ………………………… iii. Depth (mm) …………………………

b. Weight, fully equipped (kg) ………………………… c. Clearance required in front of Cubicle (mm) ………………………… d. Clearance required behind Cubicle (mm) …………………………

21.5 Control Supply a. Control Voltage (V DC) ………………………… b. Maximum Current at Nominal Voltage per Cubicle (A) ………………………… c. If a voltage other than 48V DC has been chosen, has documentation supporting this

been attached? YES / NO

21.6 Protection System a. Relay Manufacturer ………………………… b. Relay Model ………………………… c. Is full access available to MTM to alter relay settings and configuration? YES / NO d. MTBF at 45° ambient temperature (years) …………………………



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21.7 DCCB a. Manufacturer ………………………… b. Model ………………………… c. Rated Mechanical Endurance (operations) ………………………… d. Rated Operating Voltage (V DC) ………………………… e. Rated Insulation Voltage (V DC) ………………………… f. Rated Insulation Level

i. 1 min Power Freq. Withstand Voltage (kV RMS) ………………………… ii. Impulse Voltage (kV peak) …………………………

g. Maximum Transient Arc Voltage (kV) ………………………… h. Rated Short-Circuit Current

i. Prospective (peak) Current (kA) ………………………… ii. Rate of Rise (A/μS) …………………………

i. Rated Continuous Currents i. Feeder DC Circuit Breaker (A DC) ………………………… ii. Rectifier DC Circuit Breaker (A DC) ………………………… iii. Bus-Tie DC Circuit Breaker (A DC) …………………………

j. Overload duty cycle ………………………… k. Feeder DCCB Direct Acting Overcurrent Setting Range

(A DC) ………………………… l. Rectifier DCCB Direct Acting Overcurrent Setting (A DC) ………………………… m. Operations under load before maintenance required

(operations) …………………………

21.8 Bus Tie Disconnection Facility a. Manufacturer ………………………… b. Type Fixed / Link Truck c. Model ………………………… d. Expected life (operations) ………………………… e. Isolating Distance (mm) ………………………… f. Rated Operating Voltage (V DC) ………………………… g. Rated 1 min Power Freq. Withstand Voltage (kV RMS) ………………………… h. Rated Making Current (kA) ………………………… i. Rated Short-time Current (250 ms) (kA) ………………………… j. Rated Continuous Current (A DC) …………………………



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21.9 Short Circuit Switches a. Manufacturer ………………………… b. Model ………………………… c. Mechanical Endurance (operations) ………………………… d. Method of Isolation from Busbar Racking / Disconnector e. Isolating Distance (mm) ………………………… f. Rated Making Current (A) ………………………… g. Rated Short-time Current (250 ms) (A) ………………………… h. Busbar short circuit switch mounting Fixed / Truck

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TECHNICAL SPECIFICATION FOR A 1500V DC … · This document is the MTM technical specification for a indoor metal-clad 1500V DC n ... • busbar compartment ... TECHNICAL SPECIFICATION