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Transformer Commission & Testing

Transformer Testing and Substation Maintenance

Transformer Testing Substation MaintenanceNPM Services, Inc. offers a full line of substation maintenance services. We offer both preventative maintenance transformer testing and transformer commissioning, vacuum breaker, magnetic breaker, air blast breakers, SF6 Breaker, Regulators, Metal Clad Switchgear, Relays, Cables, Bus, If it carries current there is a good chance that we have experience with it.

We have the capability to perform the following tests: Power Factor Testing, Turns Ratio Testing, Winding Resistance, Insulation Resistance, Tap Changer Contact Testing, High Current Testing, Relay Testing, CT Testing, Cable Testing, Ground Resistance Testing, etc.

Power Factor Testing

Instrumental in Substation Maintenance programs. Power factor testing is used to measure the suitability of electrical equipment for continued service by measuring the insulation characteristics of electrical apparatus. Power factor testing is very useful in determining moisture present in insulation.

Turns Ratio Testing

Used to measure the turns ratio of the high voltage winding to the low voltage winding of transformer. Turns ratio testing identified early turn to turn shorts within the transformer.

Winding Resistance

Detects loose electrical connections within the transformer, and or tap changer. Test can also measure the resistance of each individual coil within the transformer.

Insulation Resistance

DC Megger test used a down and dirty insulation check. The DC Megger can also be used to perform a polarization index test. The PI test is the 10 minute insulation reading divided by the 1 minute reading. The PI test is an indication of moist or dirty insulation.

Tap Changer Contact Testing

Test which measure the make and break of tap changer contacts. Can determine contact condition and misaligned contacts.

High Current Testing

Used to verify proper trip operation of low voltage circuit breakers. Injects high current through the poles of circuit breaker so that proper trip operation can be verified.

Relay Testing

Relay testing inject low secondary current into the relay to verify trip operation of the relay.

CT Testing

Key substation maintenance test used during commissioning. Used the verify proper polarity, excitation, and knee points on current transformers.

Cable Testing

We use an AC VLF hi- pot tester to determine cable quality, and suitability for continued use. The test sweeps out a 0.1hz signal at test voltage for a duration of typically 30 minutes.

Ground Resistance Testing

Ground resistance testing can be used to measure soil resistivity, ground rod resistance, or complete grounding grid evaluation.

We would be happy to discuss you substation maintenance needs and develop a program which meets your reliability needs.
Electrical Testing and Electrical Maintenance

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