Equipment Audits for LV, MV, HV for annual mandatory record keeping by Niels

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Technical Report SAFE™ Audit of 3.3 & 11kV Switchoards

Substation name Customer Location

2014/01/13

Infrastructure & Cities Sector

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Table of contents 1. General information ...................................................................................................... 3

2. Chart of Medium voltage condition ............................................................................. 5

3. Summary ....................................................................................................................... 6

4. Safety ........................................................................................................................... 13

5. Visual inspection when asset in operation ............................................................... 14

6. Environmental sustainability ..................................................................................... 25

7. Maintenance recommendations ................................................................................ 26


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1. General information

Audit

Customer

Country South Africa

Location

Substation name

Asset type Siemens 8BD 11kV & 3.3kV

Type Siemens 8BD Panels 3AC / 3TL5

Serial number B4E213765

Date 2014/01/13

Remarks Audit for assessing life-time status

Auditor

Name Niels Inderbiethen

Department AFR RC-ZA IC-SG SE MCS

Telephone +27 (10) 222-7315

Fax

E-mail [email protected]

Customer data

Contact person (technical)

Telephone number of the contact person TBA

Fax number of contact person TBA

E-mail of contact person TBA

Postal Code TBA

Town

Street, No.


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Technical Information

Manufacturer Siemens

Type designation of switchgear Siemens RSA Type: 8BD 11kV 25kA & 3.3kV with 3AC Circuit breaker & 3TL5 Contactor Trucks

Standard IEC 60298 / VDE 0670-6 (metall closed)

Year of manufacture of switchgear 1976

Substation arrangement Double busbar

Installation Indoor

Number of bays 5

Number of spare bays A few may become available once plant redundancy is established

Serial numbers TBA

Air insulated metall closed switchgear Yes

Gasinsulated metall closed switchgear No

Remark none

General remarks by auditor There is a serious water problem in the cable basement

General remarks by customer problems with corrosion and blow ups being experienced

Rated voltage 12 kV

Rated lightning impulse withstand voltage 95 kV

Control voltage (DC/AC) DC

Control voltage 110 V

Rated short circuit breaking current 25 kA

Maximum busbar current 2000 A

Rated current supply 2000 A

Rated current feeder 1600 A

Historical Information

Years of operation since first commissioning 36-40 years

Are maintenance reports available? No

Have circuit breakers been modified? Yes

When? Various occasions

Remarks some are from other switchgear panels


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2. Chart of Medium voltage condition (Weighted average of evaluated attributes. 0: very good --> 100: bad)

0

20

40

60

80

100Battery system

Busbars

Bushings

Circuit breaker

Condition of building

Current transformer

Grounding

Load-break switchLow voltage switchgearMeasurement

Metering

Natural

Ageing

Post insulators

Protection and

secondary system

Safety

Switchgear accessories

Voltage transformer

Maintenance requirements

Natural Ageing ████ Very critical attributes were found. Immediate action required.

Safety ████ Very critical attributes were found. Immediate action required.

Condition of building ████ Critical attributes were found. Repair or replace as soon as possible.

Switchgear accessories ████ Very critical attributes were found. Immediate action required.

Circuit breaker ████ Very critical attributes were found. Immediate action required.

Load-break switch ████ Very critical attributes were found. Immediate action required.

Grounding ████ No unfavorable attributes were found. No action is required.

Post insulators ████ Very critical attributes were found. Immediate action required.

Bushings ████ Very critical attributes were found. Immediate action required.

Busbars ████ Very critical attributes were found. Immediate action required.

Current transformer ████ Harmful attributes were found. Repair during next planned maintenance (monitoring).

Voltage transformer ████ Very critical attributes were found. Immediate action required.

Metering ████ Harmful attributes were found. Repair during next planned maintenance (monitoring).

Measurement ████ Harmful attributes were found. Repair during next planned maintenance (monitoring).

Prot & sec system ████ Harmful attributes were found. Repair during next planned maintenance (monitoring).

Low voltage switchgear ████ Very critical attributes were found. Immediate action required.

Battery system ████ Harmful attributes were found. Repair during next planned maintenance (monitoring).


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3. Summary

The 3.3kV Panel is being affected by the water moisture from the cable trench, rust & deterioration is evident on all parts and components. The copper has turned blue from oxidation although the equipment can be exchanged by retrofit and all parts can be restored by our artisans. It is however essential for further life expectancy not to be affected negatively from such a point forward, that all leaks from walls, basement and roof areas are fully repaired by major civil work, if required. A larger expenditure on the civil side will ensure that any refurbishment undertaken would last in simillar time period to a completely new panel. The circuit breakers and contactors can be retrofitted with new equipment as this is the heart of the switching & equipment.

3.3kV Panel photo’s


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Panel 01 Panel 02 Panel 03 Panel 04 Panel 05

Doors of the LT compartment are relatively easy to replace and new cut-outs could be introduced for the protection that is required, even if the relays are considered to be changed for any different application. Another advantage of leaving the old panel in place and refurbishing in situ, is that all cables can remain connected, or re-terminated if suspect, being left undisturbed without placing stress on them as would occur if panels are completely removed and replaced. The old front covers would naturally be replaced if the circuit breaker and contactor trucks are retro-fitted with new equipment giving the panel front a completely new appearance with the retrofit new front covers that would be completely re-sprayed (properly powder-coated). We noted that the LT compartment wiring and terminals are still in a good condition and this could even remain as it is without any new re-wiring costs, One would possibly only need to replace a terminal or re-do a connection here or there, but the present condition makes for easy new equipment wiring integration. There were a few melted trunking pieces noted however anything of this nature can be replaced quickly and easily at no major cost impact

3.3kV Panel photo’s (continued)


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CT housings, although they will become more porous with age and may attract moisture, fitting heaters in these panels in each tier can overcome these problems and really extend the life of this equipment. It is not to say that they are guaranteed to last forever, but from our past experience with retro-fitting we must mention that thusfar no major failures have been experiend simply due to age, as all failures are usually mostly triggered by a specific cause. Contacts within the busbar housing connecting the c/b arms can all be cleaned checked and replaced if necessary.

Circuit Breakers & Contactor Photo’s The circuit breakers and contactors are more problematic as these pose the greatest of all issues for further use. Due to oil fire hazzards, we would recommend to go for vacuum exchange breakers and contactors as this would be most cost effective. SF6 is slightly more expensive and can also be a lot more specialised & problematic to maintain. Vacuum you can basically install & not worry about.

3.3kV Panel photo’s (continued) – Busbar Chamber


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Circuit Breakers & Contactors continued If contactors are retro-fitted the advantage of fuse protection , esscpecially on motors is not lost. Fuses are relativelt easy to obtain and still provide the best and fastest protection.

3.3kV Panel photo’s (continued)


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In past experience we have seen many times that electromechanical relays can outperform much of the digital technology available today. Digital relays are very temperature sensative and generally there are many reports of relays failing or losing e-prom memory due to the temparatures in electrical panels sometimes exceeding 47 degrees in summer during heavy feeder loading when temperatures rise even within the LT compartment. Due to the fact that there is no forced cooling in the sub and that installing such system is very expensive, we must side with advising to stick with the present protection systems installed. If these are regularly tested and calibrated they will still work for a very long time without giving much trouble, as contacts, bi-metals and coils can be easily replaced.

11 kV Switchboard Panel photo’s


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11kV Panel 01 11kV Panel 02 11kV Panel 03 11kV Panel 04

All parts on the equipment now visibly damaged would be completely new with a retro-fitted solution. We would also advise to exchange the spouts as these are part of the safety and protection,

11kV Panel General Overview photo‘s

11kV Panels 01 to 04 visual front view


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11kV Panel Busbar Chamber internal photo‘s

The busbar chambers are in need of immediate attention, however it must be stated that repairing the existing copper, cleaning it so that the surface is again shiny and then rather ray-chem sleeving this or using a type of resin paint on all non-contact surface areas, would again renew and protect the copper for a very long time. Insulators can all be exchanged cheaply and all the contact spouts can also be replaced with new ones. Re-allignment can be checked if correct and set if not. Fire protection or proofing can also be done in any open areas toward the basement by closing any openings. Heaters can also be fitted in busbar chamber to retain dry conditions. For any chambers with prior damage they may also either be painted with glyptol, or a new piece of thinly cut haysite can be aplied to damaged metal areas to prevent future flashovers completely in these areas.

11kV Panel Cable Compartment internal photo‘s

The cable compartments also look affected by corrosion due to the moisture, however these areas can also be treated re-painted or coated with resin to ensure a long life further forward. The cables however have been immersed in the water below the cable trench for some time now and ideally these should all be tested to ensure that the insulation has not been compromised.

However if civil work is done to stop the water problem this will no longer have any affect on the cable life expectancy and they will remain dry.


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4. Safety

Staff protection

Personnel protection insulation DIN VDE 0106 (IEC 60990)

Personnel protection insulation DIN VDE 0106 (IEC 60990) Bad, big impact deficiencies

Remark the moisture and carbon corrosion are posing serious dangers to safe ongoing switching

Operational safety DIN VDE 0101 (IEC 61936)

Load-break switch instead of disconnector Bad, big impact deficiencies

Remark corrosion

Switchgear interlocking unit Bad, big impact deficiencies

Remark corrosion

Operation from a safe distance Bad, big impact deficiencies

Remark operation has to be performed manually

Installation of suitable electro-sensitive protective equipment Bad, big impact deficiencies

Remark water dust & moisture creating semi-conductive earth paths

Country-specific standards

Country-specific standards considered? Yes

Which kind of? SANS

11kV Panel Circuit Breaker Chamber internal photo‘s


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5. Visual inspection when asset in operation

Environment

Altitude of site 1000 m up to 2000 m

Ambient temperature range - 5 °C up to + 40 °C

Current temperature on substation site 28

Quality of the ambient atmosphere Very humid

Installation in seismic zone No

Remark Coal dust present inside panel contributing to problems

Building

outside

Ventilation, air exhaust louver, pick safety Bad, big impact deficiencies

Remark no heaters & positive pressure

Pressure relief building Bad, big impact deficiencies

Remark high moisture content - cannot be rectified without civil works & damp / waterproofing

inside

Aisle widths sufficient / escape route available good, no defects

Remark none

Floor, floor plates Bad, big impact deficiencies

Remark Allows the water vapour to penetrate substation from basement

Cable basement, cable vault Bad, big impact deficiencies

Remark flooded permanently

Electro-installation, lighting Bad, big impact deficiencies

Remark everything in this station is losing life expectancy due to corrosion

Pollution, Humidity Bad, big impact deficiencies

Remark leaks & water from roof area, wall areas and basement


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Switchgear accessories

Isolating protective plates VDE 0682-552 Bad, big impact deficiencies

Remark some work & repairs will be required

Guide strips for protective plates Bad, big impact deficiencies

Remark corrosion

Grounding accessories VDE 683T100 Bad, big impact deficiencies

Remark Earth copper theft problem -suggestion to replace earth copper with aluminium / steel

Voltage tester VDE 682T411 Bad, big impact deficiencies

Remark was not functioning (equipment assessment to be done or replacement considered

Fuse tongs VDE 681T3 Bad, big impact deficiencies

Remark some equipment for panel operations maintenance is missing or lost

SF6-Maintenance unit available No

Switching devices


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First type of circuit breaker

Are circuit breakers installed? Yes

Principle of interruption Minimum oil

Number of circuit breakers 5 3AC type Circuit breakers and 3 type 3TL5 Vacuum contactors mixed in 8BD 11/3.3 kV Panel

Type designation of circuit breaker Various - but mostly feeders to plant transformers

Year of manufacture of circuit breaker 1976



Serial numbers 31175637

Type of operating mechanism Manual operating mechanism

Type of bodywork Trolley



Motor voltage (DC/AC) DC

Motor voltage 110 V

Number of operations in accordance with the operation counter low

Diagnosis Bad, big impact deficiencies

Remark mechanisms sliding surfaces are rusted and no longer support smooth operation affecting the closing and tripping speeds of the mechanisms


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Second type of circuit breaker

Are circuit breakers installed? Yes

Principle of interruption Vacuum

Number of circuit breakers 3

Type designation of circuit breaker Siemens 3AC & 3TL5

Year of manufacture of circuit breaker 1976



Serial numbers as per individual breakers

Type of operating mechanism Magnet drive

Type of bodywork Trolley



Number of operations in accordance with the operation counter N.A.


Remark corrosion affecting contactors in similar ways as circuit breakers with the smooth surfaces showing corrosion making these surfaces rough and slowing down contactor mag coil open and close operations-this is a common and general problem on all equipment

Third type of circuit breaker

Are circuit breakers installed? No but accessories


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First type of load break switch

Are load break switches or fuses installed? Yes

Design Fuse mounting


Number of load-break switches none (fitted are only fuses with striker pin mounting brackets on all contactor feeders)

Type designation of load break switch none

Year of manufacture of load-break switch none



Serial numbers not visible on all


Control voltage Other...

Which kind of control voltage? 30V DC

Number of operations in accordance with the operation counter Indeterminable


Remark corrosion

Second type of load break switch

Are load break switches or fuses installed? No

First type of disconnector

Are disconnectors installed? No

First type of earthing switch

Are earthing switches installed? Yes – however internal behind rear

Make proof earthing switch Yes


Number of earthing switches not determinable

Type designation of earthing switch cable earth switches if fitted

Year of manufacture of earthing switch same as panel

Manufacturer Other...

Manufacturer Siemens Italy

Serial numbers not determinable


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Second type of earthing switch

Are earthing switches installed? No

Earthable fixpoints

Are earthable points installed? No

Components

Post insulators

Are post insulators installed? Yes

Type Cast resin


Condition Dirty

Remark becoming saturated with moisture

Bushings

Are bushings installed? Yes

Type Cast resin


Condition Damaged

Remark damaged cover flaps & dirt / carbon build up is dangerously high

Busbars

Are busbars installed? Yes

Insulation Air insulated

Material Copper

Cross section 2 by 10


Remark as per pics the copper inside the panel has all turned seriously blue from oxidation, moisture, harmful atmosphere & the resulting corrosion

Current rails

Are current rails installed? No


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Current transformer incoming feeder

Are current transformers installed? Yes

Design Post insulator instrument transformer

Insulation Cast resin

Type Current Electric

Year of manufacture assumed same as panel

Manufacturer Current Electric

Quantity several spread out among feeders, incomers, etc.

Serial numbers Name plates are taped to the LT compartment walls

Core data of 1st core (Example: 200/1 A, 15 VA, 5 P 20) as plates

Core data of 2nd core (Example: 200/1 A, 15 VA, 5 P 20) as plates

Core data of 3rd core (Example: 200/1 A, 30 VA, 1 Fs 5) as plates

Core data of 4th core (Example: 200/1 A, 15 VA, 5 P 20) as plates

Diagnosis Medium, insignificant deficiencies

Condition of current transformers Very dirty

Remark the panels could be cleaned on in situ on site & re-insulated, treated and cleaned and re-painted

Current transformer outgoing feeder

Are current transformers installed? No


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Voltage transformer

Are voltage transformers installed? Yes

Design Conventional

Type 8BD - VT Rueksak

Year of manufacture same as panel


Quantity 1 on the 11kV Board & 1 on the 3.3kV board

Serial numbers not visible during operation

Primary voltage (Example: 110 000/√³ V) 11000

Secondary voltage of the measurement winding (Example: 110/√³ V) 110

Earth fault winding Yes

Class standard 11kV VT

Voltage factor (Example: 1.9 * Un, 4 h) standard


Condition of voltage transformer Very dirty

Remark a complete opening of VT housing is recommended and clean and full service and test

Surge Arresters

Are surge arresters installed? No

Over voltage limiter

Are overvoltage limiters installed? No

Secondary Systems

Metering

Is a counting facility available? Yes

Manufacturer various as per each panel LT relays mounted in relay compartment

Type also various


Remark we assume or suggest that all protection relays are all tested at least once each year for full functionality and records of this are/ must be kept in the substation


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Measurement

Is a measuring facility available? Yes

Manufacturer Various

Type KWH Relays



Protection

Are protection devices installed? Yes

Protection electromechanical

Distance Protection

Distance Protection Yes

Manufacturer GE

Type Electromechanical



Differential Protection

Differential Protection Yes

Manufacturer GE

Type Electromechanical




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Over current protection

Over current protection Yes

Manufacturer Other

Manufacturer various

Type Over current & Earth fault



Busbar protection

Busbar protection No

Low voltage switchgear

Are low voltage switchgear installed? Yes


Type LV 400V Isolators & feeder circuit MCB's

Year of manufacture unknown

Personnel protection insulation in accordance with DIN VDE 0106 (IEC 60990)

No


Remark Safety PPE like 1kV Electrical insulated gloves and specially insulated tools need to be available for the staff, including all panel electrical documentation on LV & MV

Battery system

Does DC auxiliary supply equipment exist? Yes


Type various

Year of manufacture various




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Compressed air generation

Is a compressed air generation available? No

Other

Other none

Documentation

Documentation

Documentation Not available/not installed

Remark we could only visibly see the single lines, all sundry documentation for every control circuit present in the sub should be openly available and accessibly labelled

Files

Attach file 1 All pics Ziped1.zip

Attach file 2 All pics Ziped1_2.zip

Attach file 3 All Pics for 11kV Board 1 of 2.zip

Attach file 4 All Pics for 11kV Board 2 of 2.zip

Audit Configuration

The first level of the audit is complete. How do you want to proceed? -The customer requests FUTURE consulting or thorough investigations


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6. Environmental sustainability Conclusion

Important status parameters of the tested system indicate high risk of environmental hazard. Please observe the maintenance recommendations. The general status of the substation environmental condition is presently poor due to the water and damp leaks into the substation. Although one must mention that the general safety applied in the station is good.


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7. Maintenance recommendations Safety Personnel protection insulation DIN VDE 0106 (IEC 60990) - The located weakpoints regarding personnel protection insulation have to be removed immediately Operational safety DIN VDE 0101 (IEC 61936) - The located weakpoints have to be removed immediately Natural Ageing - The actual ambient conditions may require additional maintenance works Condition of building outside - The located weakpoints on the building have to be removed immediately inside - The located weakpoints on the building have to be removed immediately Switchgear accessories - Exchanging equipment - (start planing for older equipment exchanges) - Exchanging equipment - (Check enough critical spares are still on hand to have sufficient time to implement) - Exchanging equipment - (after anual testing, if found faulty, exchange with new as necessary or advised) - Exchanging equipment - (circuit breakers can easily be exchanged (oil fire hazzard) rather for new vacuum) - Exchanging equipment – (contactors can easily be exchanged / retrofitted with new ones at minmal outlay) Load-break switch First type of load break switch - Maintenance of operating mechanism. Post insulators - Maintenance of insulators.


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Bushings - Maintenance of insulators. Busbars - Maintenance of insulators. Current transformer Current transformer incoming feeder - Maintenance of the equipment Voltage transformer - Maintenance respectively repair of the instrument transformer 1

Please note: This audit report summarizes only the existing condition of the customer’s electrical equipment and system at the time when the audit was performed. Please note that any subsequent changes of the equipment, system or equipment’s operation may cause inconsistency between the report’s summary and the subsequently changed conditions. Siemens cannot be held liable for such inconsistency. Charts, diagrams and graphics in this report are merely illustrations to summarize and to provide an overview of the condition of the customer’s electrical equipment and system at the time the audit was performed. No conclusions should be made and no further measures should be taken based exclusively on the graphic presentations included in this report. Siemens shall not be liable if the information included in this report is not handled or otherwise used with the necessary expert knowledge and thereby damage of any kind is caused. Siemens shall not be held liable for technical developments which supersede or invalidate the information in the report, if these could not have been reasonably known or identified prior to the time when the audit was performed.

Services

Equipment Audits for LV, MV, HV for annual mandatory record keeping by Niels