Mtekpro Service Profile

(-- Condition Monitoring Services --) Motors Cables Switchgear Generator Transformer Substation Overhead Transmission line Batteries Bank

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Condition Monitoring Services for Electrical Equipment

Condition Monitoring Services for Electrical Equipments

Abstract: - Condition monitoring of electric machinery can significantly reduce the cost of maintenance and the risk of unexpected failures by allowing the early detection of potentially catastrophic faults. In condition based maintenance, one does not schedule maintenance or machine replacement based on previous records or statistical estimates of machine failure. Rather, one relies on the information provided by condition monitoring systems assessing the machine's condition. Thus the key for the success of condition based maintenance is having an accurate means of condition assessment and fault diagnosis.

The goal of a predictive maintenance program is always the same. Reducing unscheduled downtime by predicting imminent failures and identifying problem areas, determining the root-cause problem of failures and, ultimately, to save money.

Electrical systems are among the most valuable assets in your plant and can have the biggest impact on your bottom line. Their production and management costs are high, and failures almost always lead to catastrophic losses. Electrical systems are being operated at higher levels, even while systems are aging—which affects both the life and the reliability of the assets.

Today’s asset managers are facing the increased challenge of maximizing their aging electrical infrastructure with fewer qualified technical in-house resources, stricter regulatory requirements for worker safety, and shrinking maintenance budgets.

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Motors:-Introduction: - Motors are a part of a “system” which includes the incoming power, the load and, of course, the motor itself. Maintaining the safe and profitable operation of plants and facilities, demands a high degree of motor reliability. The Refinery industry ranks at the top of this requirement for uninterrupted operation and safe, continued production.

Electrically testing motors is a major part of any well organized and executed predictive maintenance program. On-line and off-line testing and trending provides valuable information technicians need to make accurate decisions regarding the motors health. These technologies provide very different information as each looks at very different areas of concern. Both technologies are required to have a complete picture of operational health of a motor.

What are we really after? An effective Predictive Maintenance Program must include both static and dynamic motor testing if the program is to be successful. Each defines specific areas of concern regarding the motor system, each has its limitations, and each lends support to the other.

On Line Motor Testing:-Motor Current Signature Analysis (MCSA).Vibration AnalysisUltrasonic DetectionThermography(IR)Partial Discharge (PD)Bearing problem Analysis

Off Line Motor Testing Stator

Insulation Resistance & Polarization Index Measurement ,Dielectric Absorption TestStep Voltage TestDC / AC Hipot TestSurge TestingImpedance testCurrent Frequency responsePhase anglePartial Discharge MeasurementWinding Resistance MeasurementCapacitance and Tan Delta Measurement.

Rotor Insulation Resistance & Polarization Index Measurement Impedance Measurement Winding Resistance Measurement

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Cables:-It is noted that the insulating qualities of XLPE are very good, and that except in the case of major insulation damage such as physical puncture by a nail XLPE can withstand many times it’s rated voltage without failure (typically > 1.4 times Uo for new cable).

Most failures of XLPE cable are related to moisture ingress into joints or terminations or incorrectly applied terminations and joints (both workmanship and materials may be inadequate). One aim of testing of HV cables is to expose, in controlled conditions, any faults that will result in premature failure of the cable and associated terminations.

We have the capabilities to do following test:-

Cable Sheath TestingInsulation Resistance Testing VLF AC withstand test Tan Delta Testing DC Hipot of CablesCable Fault LocalizationPin Pointing of fault in cables and Route tracing,Partial Discharge (PD) measurement (On line/ offline)Cable Identification.Standards followed: IEEE 400.2, IEC 60060-3, IEEE P400.2

Partial Discharge (PD) measurement (online):- High voltage insulation breakdown has been the main causes of high voltage system breakdown. It is found that this phenomenon occurs due to the existence of partial discharge within voids found in the insulation of XLPE cables, which is produced accidentally

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during the extrusion process of the cables. The effect of partial discharge would lead to serious breakdown of power cable systems and electrical apparatus failures. Many appropriate techniques can be used to evaluate the condition of XLPE cables. Many appropriate techniques can be used to evaluate the condition of XLPE cables. One of the techniques is partial discharge testing.

Partial discharge detection is nowadays a very well established method for monitoring the insulation condition of an electrical apparatus. The breakdown of insulation while in service can cause considerable damage to an apparatus and to the system to which it is connected. It has been recognized that failures of this type often may be related to the occurrence and severity of partial discharges within voids and/or on the surface of the insulation medium.

Problem Identification

Using our integrated Partial Discharge testing and monitoring solutions, our test engineers can identify:

Defective Cable InsulationLocation of DefectsExtent of Insulation DegradationDefective SplicesDefective Terminations

Benefits of Partial Discharge testing on cable

Performed online without disrupting plant or facilities, or offline when requiredNon-destructive, non-invasive predictive maintenance toolsOptimizes capital expenditures and improves system reliabilityHelps eliminate unplanned outages and lost profit as a result of system Downtime Identifies and prioritizes cable sections and terminations for replacementFocus on the right cables for targeted investment—minimizes unnecessary spending.

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Switchgear:-Online Partial Discharge Testing is performed online without disrupting plant or facility operations. This non-destructive, non-invasive predictive maintenance tool assesses the condition of switchgear, feeder cables, and bus duct to provide critical information regarding the levels of partial discharge and its potential impact on the health of the electrical asset. The cost to perform online testing is relatively inexpensive compared with offline testing that requires interruption of service and production. For critical facilities that operate 24x7, online testing is considered the single best option for detecting insulation condition.

Benefits Performed online without disrupting process operations offline for commissioning

new gear. Non-destructive, non-invasive predictive maintenance tools Optimizes capital expenditures and improves system reliability Helps eliminate unplanned outages and lost profit as a result of system downtime

Problem Identification

Using our Integrated Partial Discharge Testing and Monitoring Solutions, our test engineers can identify:

Surface TrackingCoronaPartial discharges within insulators and insulating componentsDefective insulation in cable terminationsSurface contamination or moistureDefective potential transformers and current transformersDefects in circuit breaker insulation structure

Fig: Acoustic sensors on panel.

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PD Testing Services can be classified in two parts:-

1) PD Detection :- We have the capabilities to detect Partial Discharge by following methods:-

Acoustic: Band Width- 20 kHz- 300 kHzTEV (Transient Earth Voltage): Band Width- 3 MHz- 100 MHz UHF (Ultra High Frequency): Band Width- 300 MHz- 1500 MHzHFCT (High Frequency Current Transformer): Band Width- 500 kHz- 50 MHzUltrasonic: Band Width- 40 kHz

2) PD Localization and Pin Pointing: - It includes result analysis and pinpointing of PD in switchgear Panel.

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Generator:-

Tests offered by us:-

Insulation Resistance and Polarization Index Capacitance and Tan Delta Measurement Partial Discharge Measurement DC/AC leakage Current Measurement(Hi Pot) DC Winding Resistance measurement.

Transformer:-Page 8 of 13


Power transformers are the central hub in the field of energy distribution and transmission. As such, their condition is critical for reliable, fault-free operation. Any failures can have serious consequences. The resulting overloads of grid sections can lead to far-reaching supply and production failures. A total failure of the insulation can lead to personal injury as well as to immense damage of property.

Preventive replacement after a certain number of operating years is often not an economically viable alternative, since the associated costs of replacing this asset can be enormous and the aging depends on the conditions in which the transformer is operated. Therefore, condition- or time-based asset testing and diagnostics have established themselves as the better option. Monitoring systems can also represent an effect solution, if problems are suspected or the transformers are positioned at strategically important locations.

Test Performed by us:- Turns Ratio and Vector Group

Measurement Magnetic Balance and Magnetizing

Current Measurement % Impedance Measurement at Low

Voltage Insulation Resistance & Polarization

Index Measurement DC Winding Resistance Measurement Dynamic Contact Resistance

Measurement of OLTC SFRA (Sweep Frequency Response

Analysis) Testing

Tan Delta and Capacitance Measurement.

Partial Discharge (PD) Measurement (On-line & Off-line)

Magnetic Circuit (Insulation) Test Functionality Check of all Protective

Devices Stability Check Oil Analysis. Standards followed: IEC 60270 (for

PD), IEC 60060-1, IEC 60060-3, IEC

Substation:-

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Sr. No. Test Objects Test Parameters

1

PowerTransformer &Reactors

Turret CT testing for Insulation Resistance, Magnetizing Current, Ratio, Winding Resistance & polarity of CT before erection. After Filtration, Insulation Resistance Measurement with PI & DAI, Vector Group, Magnetizing Current, Magnetic Balance, Turns Ratio, capacitance & Tan delta of winding and bushing, Winding Resistance, OLTC Operation, Operational checks for Buchholz, WTI,OTI, Fan control, Failure Protection checks, SFRA, Partial Discharge Testing. Spill Current Measurement, Stability measurement.

2 DistributionTransformer

IR Test, Vector Group, Ratio, Magnetizing Current & Magnetic Balance.

3 Circuit BreakerIR, Static Contact Resistance, Closing & Opening time & DCRM with Analyser, Travel Measurement, Functional Checks, and Close/Trip coil Current & Resistance, Dew point of SF6 Gas.

4Currenttransformers

IR test, Polarity, Ratio test, Knee Point voltage for PS class, capacitance & Tan delta.

5 ISOLATOR IR test, functional Check of counter, Earth Resistance, LCM & Tan delta is offered as optional).

6

Control & relayPanel

Secondary Injection Test for all Relays by conventional 1 Ph current Test set, Protection, Control & Annunciation scheme checking. Relay testing with 3 Ph Automatic kit with configurations.

7Battery & batteryCharger

Charging/ Discharging cycle by conventional method, measuring of voltage per cell. Deputation of Engineer 24 Hrs during charging cycle.

8 ACDB/DCDB IR test, Functional check of counter.

9 CVT/PT Capacitance & Tan Delta of each stack and total, IR test, Ratio Test

Over Head Transmission Line:-Page 10 of 13


Many transmission and distribution lines in world are very old. Some conductors and shield wires have been in service for more than 40 years—well past their intended design life—with rates of deterioration largely unknown. As lines continue to age it becomes increasingly important for utilities to know the existing physical condition of the aged conductors to optimize management of these important assets.

LineVue:-

A new device, called LineVue, uses this technology to non- destructively inspect conductors with steel cores (i.e. ACSR and ACSS) and steel Shield wires in the field.

LineVue™ tool assesses the integrity of transmission conductors to help reduce transmission line failures, maintain reliability of service, and reduce safety risks.

Remote controlled and easy-to-use in the field Detects local faults such as severe pitting or broken steel wires over ~ 1 inch Measuring the remaining steel core cross-section provides a direct assessment of the

most important conductor parameter—actual remaining strength—and LineVue™ does this.

How Does LineVue Work?

Permanent magnets are used to saturate the steel core with a magnetic flux. Magnetic flux is proportional to the cross-sectional area of steel Point discontinuities will also cause the magnetic flux to “leak” radially from the steel

in the immediate vicinity of the flaw.

Two Inspections:-

1) Loss of Metallic Cross-Sectional Area (LMA) Inspection- quantitatively measures the remaining steel area caused by corrosion and wear using Hall Effect Sensors

2) Localized Flaw (LF) Inspection - qualitatively detects discontinuities such as broken steel wires and corrosion pitting using coils.

Corona Testing:-

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Corona discharge is a luminous partial discharge from conductors and insulators due to ionization of the air, where the electrical field exceeds a critical value.Corona cameras can direct maintenance engineers to the exact location of the failure, and cut sharply both direct inspection costs and indirect costs of un needed washing, un needed replacements, unexpected shutdown, extending parts lifetime, deferring aging processes.

Corona has the following damaging and environmental disturbing effects:-

Corona causes damage to HV insulators, especially non-ceramic ( NCI) insulators

Radio interference (RI/ RFI) mainly to AM transmissions. Audio noise. Radio interference and audio noise may raise customer

complaints. Corona generates only little heat and therefore is not detected with

thermovision cameras.

Benefits:

Perfect for long distance and remote inspectionExtended yet comfortable working hoursImmediate results with playback of the captured findingsMulti system inspection streamlines inspection procedures and reduces manpower costsAccurately pinpoints sources of: audio noise, radio/TV interference, micro arcing, corona and arcingFly in a safe distance and high speed without missing coronas

Battery Bank:-Why battery backup is needed?

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Batteries are used to ensure that critical electrical equipment is always on. There are so many places where batteries are used and it is nearly impossible to list them all. Some of the applications for batteries include:

Electric generating stations and substations for protection and control of switches and relays

Telephone systems to support phone service, especially emergency services

Industrial applications for protection and control Back up of computers, especially financial data and information “Less critical” business information systems.

Why to test battery systems?

There are three main reasons to test battery systems: to insure the supported equipment is adequately backed-up to prevent unexpected failures by tracking the battery’s health to forewarn/predict death

Testing services offered by us:-

Battery Bank Condition Monitoring Voltage Measurement Impedance Measurement Sulfation measurement. Dryout Measurement. De- Sulfation of Sulfated Battery Battery Bank Discharging Services. Specific Gravity Measurement.

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Mtekpro Service Profile