TESTING PLAN

Testing plan is divided into three types of tests.

Routine tests

To be carried out by the manufacturer on all the units, for which a routine test certificate will be supplied.

Acceptance tests

To be carried out on capacitors, the number of which is to be decided between the customer and the manufacturer mutually.

Type tests

tests on single unit at extra costs and with previous arrangement.

Routine Tests

A

Visual examination

B

Sealing test at 80⁰C + 5⁰C for 3 Hours.

C

Capacitance will be measured directly across a Schering bridge and KVAR will be calculated from same. Unbalance between phases will not exceed 5%.

D

Insulation resistance will be measured on a microampere ammeter across a 500 volts stabilised, ripple-free D.C. supply between all the terminals together and container and the value so measured will not be less than 50 MW .

2) Readings with hand Megger are not reliable.

E

1. A D.C. Voltage Vt = 4.3 rated voltage (Vo) will be applied for 10 seconds between terminals. The capacitor will withstand this test.
2. We do not offer A.C. voltage test between terminals. It requires a very high KVA capacity from the source.

On subsequent repeated testing, test voltage applied will be equal to 80% of the above value.

F

An A.C. voltage will be applied as per table below between all the terminals together and body for the period of 1 minute. The capacitor will withstand this test.

Power Frequency and Impulse Test Voltages.

KV (r.m.s.)

KV (r.m.s.)

KV (peak)

3.6

16

45

7.2

22

60

12

28

75

17.5

38

95

24

50

125

36

70

170

52

95

250

72.5

140

325

140

275 (For full Insulation)

650 (For full Insulation)

2) For Type test, the duration will be 1 minute & for routine test the duration will be 10 seconds.

G

This test will be similar to the above except that all the fitting like voltmeter, instrument transformer or any other phase to earth apparatus may be disconnected during this test.

H

A D.C. Voltage equal to 1.41 times the r.m.s. rated voltage of capacitor will be applied along with its discharge resistance. The voltage will be switched off and time will be measured to reduce this voltage upto 50 volts. This time will be less than 5 minutes.

I

This will be measured across the Schering bridge at rated voltage. Output test will be repeated at the end of above series of tests.

Acceptance tests

All the routine tests are offered as acceptance tests.

Type tests

Following type test are identical to similar tests under routine test

A

Test for output and capacitance.

B

Voltage test between terminals and container (for capacitor unit)

C

Voltage test between terminal and container (for capacitor bank)

D

Voltage test between terminals

E

Measurement of tan delta.

F

Thermal stability test will be carried out as per clause 15 of IS:2834.

G

Tangent of dielectric loss angle at elevated temperature. Tan delta during the thermal Stability test at the voltage of the thermal Stability test will be as per declared value.

H

Impulse Voltage test between all live terminals together and the container as per table and conditions of clause (f) in routine tests.

I

Partial discharge test.

J

Capacitance discharge test.

A capacitor unit will be charged to D.C. voltage at twice the rated R.M.S. voltage and discharged through a gap situated as close to capacitor as possible without a current limiting resistance. Five such discharges will be carried out within an interval of 2 minutes between two shots. The unit has to withstand a voltage test between terminals after this test. Capacitance before and after this test will not vary by more than 2%.