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TESTING OF H.T.

MOTORS

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RANGE OF MOTORS & TYPE OF

M/Cs.

RANGE : 140 KW TO 40 MW

TYPE OF M/Cs

INDUCTION : SLIP RING INDUCTION MOTORS: SQ. CAGE INDUCTION MOTORS

SYNCHRONOUS : MOTORS & GENERATORS

VFD MACHINES ( VARIABLE FREQUENCY DRIVE )

FLAME PROOF , PRESSURISED MACHINES.

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TYPES OF TESTS

1.0 IN PROCESS OR STAGE TESTS :

MEASUREMENT OF

RESISTANCE, IMPEDANCE, IR , PI, TAN DELTA

AND HV

TEST . MAGNETIC CENTRING .

2.0ROUTINE TESTS : TO CHECK GENERAL

PERFORMANCE

OF ASSEMBLED MOTOR ON TEST BED.

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LIST OF ROUTINE TESTS.

1.0 COLD RESISTANCE.

2.0 PHASE SEQUENCE / DOR

3.0 MECHANICAL RUN OF MOTOR AT NO

LOAD.

4.0 NO LOAD CURVE , SHAFT VOLTAGE &

VIBRATIONS.5.0 LOCK ROTOR TEST.

6.0 POLARISATION INDEX ( >1.5).

7.0 AC H. V. TEST AT (2XU+1) FOR 1

MINUTE.

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TYPETESTS1.0NO LOAD SATURATION CURVE( FROM 125 %RATED

VOLTAGE TO 25% RATED VOLTAGE.)

2.0 DETERMINATION OF STARTING CURRENT &

STARTING

TORQUE BY LOCK ROTOR TEST.

3.0 LOAD POINTS AT 100 %, 75% & 50 %.

4.0 OVER LOAD AT 160% RATED CURRENT.

(SUBJECT TO

TEST PLANT LIMITATION.

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1.0IP 55 (IInd NUMERAL)

2.0TAN DELTA TEST ON MACHINES ABOVE 3.3 KV

3.0IMPULSE TEST AT (4 U+5) KV . U=LINE VOLTAGE

4.0RETARDATION TEST.

5.0 PRESSURISATION TEST.

6.0 VOLTAGE DECAY

7.0 WORKING OF BACKSTOP

8.0 EXTENDED NO LOAD RUN

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.

-FRICTION & WINDAGE LOSSES FROM NO LOAD CURVE-IRON LOSS FROM NO LOAD CURVE

-STATOR Cu LOSS ( 3X Isq.R )

-ROTOR Cu LOSS (Slip X AIR GAP POWER)

AIR GAP POWER= INPUT-St. Cu LOSS-IRON LOSS-STRAY LOAD LOSS = 0.5 % OF OUTPUT

-OUTPUT=INPUT-LOSSES

-EFFICIENCY= (OUTPUT/INPUT)X100

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TOTAL LOSSES : +10%

POWER FACTOR (Min 0.02 & Max 0.07) : 1/6(1-Pf)

STARTING CURRENT : +20%

STARTING TORQUE : -15%,+25%

PULL OUT TORQUE : -10%

RESISTANCE VARIATION(M/C TO M/C) : +/-10%

RESISTANCE VARIATION(PH TO PH) : +/-2%

PHASE CURRENT : +/-2%

VIBRATION AS PER IS 12075 OR VDE

NOISE AS PER IS 12005

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M/C VOLTAGE (KV) IR(AMBIENT) IR(75 C)

UP TO 1.0 KV 30 M OHMS 1 M OHMS

UP TO 3.3 KV 120 M OHMS 4 M OHMS

UP TO 6.6 KV 250 M OHMS 7 M OHMS

UP TO 11.0 KV 500 M OHMS 15 M OHMS

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-15 MVA MG SET-10 MVA MG SET-5 MVA MG SET

-2 MVA MG SET-1750 KVA MG SET-650 KVA MG SET-2000 KVA MG SET

-HIGH ACCURACY DIGITAL INSTRUMENTATIONS-POWER ANALYSERS-NOISE , VIBRATION , TEMPERATUREMEASURING DIGITAL INSTRUMENTS.-DIGITAL CONTROL OF MG SETS& M/c U/TEST.

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1. Geometrical center of stator and rotor,is not the magnetic center of machine

due to asymmetry of core & other components.

2. Magnetic force pulls the rotor to-ward centerof the stator axially.

3. Motor bearing thrust shoulders are notdesigned to carry any axial thrust exerted fromdriven equipment side.

4. Motor may hunt if it is coupled off center, and

specially w/o Limited End Float coupling .

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1.Ensure that the rotor is "level" beforeStarting the procedure

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