06-07-2012, 02:23 PM
TESTING, MAINTENANCE and PROTECTION OF DISTRIBUTION TRANSFORMERS
TESTING,MAINTENANCE&PROTECTION.ppt (Size: 3.04 MB / Downloads: 310)
DISTRIBUTION TRANSFORMER
TRANSFORMER WHICH IS USED FOR THE PURPOSE OF DISTRIBUTION OF POWER.
11KV/433V is the standard voltage rating.
STANDARD KVA ratings are
25,63,100,160,200,250,315,400,500,630,750 , 1000 , 1250,1500,2000,2500 KVA.
IS-2026 is the NATIONAL I S STANDARD.
MAIN FEATURES
OUTDOOR,OIL COOLED, 3 PHASE,50HZ
PRIMARY IS DELTA CONNECTED AND SECONDARY IS STAR CONNECTED.
NATURALY COOLED (ONAN TYPE).
AMONGST ALL THE TYPES OF TRANSFORMERS THIS IS THE MOST REQUIRED AND MOST USED TYPE.
TYPE TESTS
THESE TESTS ARE CARRIED OUT ONLY ON ONE TRANSFORMER OF THE LOT.
All routine tests
Additionally following tests are included in type tests
Lightening Impulse test.
Temperature rise test
ROUTINE TESTS
2.Measurement of insulation resistance
Measures the insulation resistance of HV & LV windings with respect to earth (body) and between LV & HV winding.
INSULATION TESTER OR MEGGER IS USED.
Recommended Values are
2000Mohms for HV & 500 Mohms for LV.