Voltage Sensing Device Interlock
Voltage Sensing Device Interlock
(OP)
Hi, I am conducting reviews on the design contractor's switchgear with separate earthing switches at their associated cable termination cubicle. I am looking on the interlocking scheme of these earth switches and noticed that part of the earth switch interlock is a "provision of a voltage sensing mechanism to inhibit earth switch closing if voltage is present on the cable". does this device exist in the market? If yes, may I request for any link related to it?
Respectfully....
Respectfully....
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RE: Voltage Sensing Device Interlock
But, define "if voltage is present on the cable". The whole purpose of a grounding switch would be to remove the voltage on the cable, so if you can't close the switch with voltage on the cable, when will you ever close the switch?
RE: Voltage Sensing Device Interlock
On the other hand (for 11kV or 3.3KV nominal voltages), even if the cable supply voltage is disconnected, a voltage is still present in the cable due to stored capacitance.
GO PLACIDLY, AMIDST THE NOISE AND HASTE-Desiderata
RE: Voltage Sensing Device Interlock
This type of set up is sometimes used to prevent electric operation of a Ground/Test device also. Saw some older Federal Pacific 15kV, 1200A, 1000MVA MC breakers use this set up to allow for actual electric racking in of the Ground/Test device into the cell.
Worked well enough until they blew a PT fuse and racked a closed G&T into the cell.
RE: Voltage Sensing Device Interlock
On the other hand, I will just suggest to place a capacitive voltage indicator at the cable termination cubicle.
respectfully...
GO PLACIDLY, AMIDST THE NOISE AND HASTE-Desiderata
RE: Voltage Sensing Device Interlock
thread279-121313
I never did find a source for them in the US, it just isn't done here and nobody understands it. We ended up using switchgear from the UK.
Eng-Tips: Help for your job, not for your homework Read FAQ731-376
RE: Voltage Sensing Device Interlock
Our client, wants to have both electrical and mechanical interlock separately for the same earth switch.
Thank you...
GO PLACIDLY, AMIDST THE NOISE AND HASTE-Desiderata
RE: Voltage Sensing Device Interlock
RE: Voltage Sensing Device Interlock
Respectfully...
GO PLACIDLY, AMIDST THE NOISE AND HASTE-Desiderata