8/13/2019 Electrical Test and Maintenance of Transformers,
Relays, And Circuit Breakers at Transformer Service Inc.
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Electrical Test and Maintenance of Transformers, Relays and
CircuitBreakers
Transformer Service, Inc. has been a leader in improving
transformer and switchgear reliability andperformance since 1952.
TSI has developed preventive maintenance strategies that identify
and curepotential problems before they affect operation or
longevity.
The cornerstones of TSIs preventive program are oil sampling,
electrical test and visual inspection.Together, these three methods
provide the information to analyze the condition of your
transformer and switchgear and to determine the steps needed to
assure reliability and top performance.
Electrical Testing
Electrical tests accurately measure these importantvalues:
Insulating value of insulation (DC Megger)
Resistive and Capacitive loss (DC Hipot)Power Factor (tests of
transformers & bushings)Relationship of primary and secondary
voltages(TTR)Trip levels and accuracy of relays and low, mediumand
high voltage circuit breakers
Test results are compared to manufacturers specificationsand/or
performance standards set by NETA, IEEE andNEMA, and establish a
baseline for comparison withfuture tests. Repairs or calibration
needed to bringequipment into specification can be easily
identified, andpost repair testing assures that proper corrective
actionhas been taken.
In many cases, testing identifies the need for simplerepairs and
adjustments that preclude costly repairs anddowntime in the
future.
Tests PerformedThe suite of tests include the following:
Dielectric AbsorptionInsulation resistance test,
winding-to-winding andwinding-to-ground.Turn to Turn Ratio Test: to
determine actual vs.calculated voltagePower Factor Test: to assess
condition of electricalinsulation in high voltage apparatusBreaker
and relay tests of contact resistance,conductivity, insulation
resistance, current and /or voltage trip levels
Equipment Used
Microprocessor based circuit breaker test sets for high current
injection5KV Insulation Resistance testers
Automated Insulation Power Factor Test SetProtective Relay Test
SetDigital Low Resistance Ohmmeters10KV automated power factor test
setTurn to Turn Ratio Test Set
RepairsOur breaker and relay test process compares the
performance of your equipment to manufacturersmaintenance
specifications. In addition to testing, our technicians perform
on-the-spot repairs such as:
Cleaning cubiclesBurnishing and adjusting contactsLubricating
moving parts
Retrofitting trip unitsRepairing faulty subassemblies
More extensive repairs are performed by returning the faulty
item to TSI or on a subsequent site visit.
http://www.transformer-svc.com/electrical_testing.htm
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