Cut Sheet

3M™
Cold Shrink QT-III Silicone Rubber Skirted Termination Kits,
7620-S, 7680-S and 7690-S Series
11 of 14
Performance Tests
(continued)
Partial Discharge (Corona) Tests
The purpose of corona testing is to determine whether all properly installed terminations
operate corona-free at a minimum of 150% of their operating voltage. For the test, an
applied test voltage is gradually increased until discharges appear on the test set
oscilloscope display. The voltage at which these discharges reach a magnitude of 3
picocoulombs is recorded as the corona starting voltage (CSV). The applied voltage is
then lowered until the discharge level drops below 3 picocoulombs, and this is recorded
as the corona extinction voltage (CEV).
Power Frequency (AC) Withstand Tests
All 3M™ Cold Shrink QT-III Silicone Rubber Skirted Termination Kits, 7620-S, 7680-S
and 7690-S Series exceed the IEEE Standard 48 requirements for a Class 1 termination.
Lightning Impulse Tests
For these tests, a 1.2 x 50 microsecond voltage wave is applied to the termination’s lug.
The testing consists of both positive and negative polarity surges per IEEE Standard 48
BIL requirements. The 3M™ Cold Shrink QT-III Silicone Rubber Skirted Termination
Kits, 7620-S, 7680-S and 7690-S Series terminations kits exceed these BIL
requirements.
Sealing Tests
Termination top and bottom seals are tested by applying 7 psi (0,05 mPa) to the cable
conductor strands with the termination submerged in water. Both seals withstand this
internal air pressure for 6 hours without leaking.
Typical Results, IEEE Standard 48 Long-Term Test Sequence
Insulation Class Test
5 / 8 kV (2 Skirt) 15/25 kV (4 Skirt)
35 kV
(8 and 12 Skirt)
Require-
ments
Results
Require-
ments
Results
Require-
ments
Results
Partial Discharge
Extinction voltage @ 3 pC
7.5 kV Passed 13 / 21.5 kV Passed 30 kV Passed
Cycling Aging
30 days, 130°C cond. temp
Power Frequency Voltage
Withstand
15 kV Passed 26 / 43 kV Passed 60 kV Passed
Partial Discharge
Extinction Voltage @ 3 pC
7.5 kV Passed 13 / 21.5 kV Passed 30 kV Passed
Lightning Impulse
Voltage Withstand (BIL)
95 kV Passed 110 / 150 kV Passed 200 kV Passed