Petroleum Storage Tanks Erection and Repair
i. TYPES OF Electrical Tests
Electrical tests accurately measure these important values:
- 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, medium and high voltage circuit breakers
- Dielectric Absorption
- Insulation resistance test, winding-to-winding and winding-to-ground.
- Turn to Turn Ratio Test: to determine actual vs. calculated voltage
- Power Factor Test: to assess condition of electrical insulation in high voltage apparatus
- Breaker and relay tests of contact resistance, conductivity, insulation resistance, current and /or voltage trip levels
ii. Test Report and Analysis
Test results are compared to manufacturer's specifications and/or performance standards set by NETA, IEEE and NEMA, and establish a baseline for comparison with future tests. Repairs or calibration needed to bring equipment into specification can be easily identified, and post repair testing assures that proper corrective action has been taken. In many cases, testing identifies the need for simple repairs and adjustments that preclude costly repairs and downtime in the future.
After the test program is completed, a test report is compiled and submitted to our customer. The test report presents the actual data taken at the customerís site and the results of any calculated values. Out of specification conditions are highlighted and maintenance recommendations are presented.
ii. Test Equipments
- Microprocessor based circuit breaker test sets for high current injection
- 5KV Insulation Resistance testers
- Automated Insulation Power Factor Test Set
- Protective Relay Test Set
- Digital Low Resistance Ohmmeters
- 10KV automated power factor test set
- Turn to Turn Ratio Test Set