Special Test on HT Cables
For MV cable testing following
special tests are done :
1. Partial Discharge Test
2. Tan delta Test
3. Lightening Impulse Test
4. 4-hour test
Purpose of PD:
1. This test is performed to assess
electrical insulation health.
1. To find the discharge before it
leads to flashover and
catastrophic failure
2. PD is best described as a
failure of part of an insulation
system to withstand the
electrical field applied to it.
Technical parameter of PD
Rated Input
100 KVA, 50 Hz
Rated output for 33KV 2000KVA, 120KV, 16.7A
Rated output for 33KV
2000 KVA, 50 KV, 40A
Lightning Impulse Test System
Technical parameter of PD
Purpose of Lightening Impulse:
1. to assess the ability of
Electrical Insulation Systems
to withstand such highvoltage impulses.
Nominal Voltage
Rated Impulse capacity
Rated energy
Charging voltage range
Working Voltage
Series
400 KV
0.111 micro Farad
20 KJ
0-100 KV
20- 100 KV
4
Thermal Cycle Test System
Purpose of Thermal cycle Test:
1.
Thermal cycling tests
determine the ability of a
cable under test (or a part of
it) to resist extremely high
temperatures and extremely
low temperatures.
Technical parameters of Thermal Cycle
Test
Input power
380V, 200 KVA, 50Hz
Temperature
sample loop
current
System working
time
35-120
1000-6000 A
Not less than 2
hours