3 pole transfer switches in series
3 pole transfer switches in series
(OP)
I have a 4w+G system in which generators and utility feed a common 3P automatic transfer switch. The load then goes to a 3w+G switchboard and then to another 3P transfer switch.
The utility is 2000kVA OA, 12470 pri Y 480/277v sec and the Generators are connected Y through a 3 pole transfer switch. The Gen's are not a seperatly derived system. I know if you have multiple switches in a row that you want to switch the neutral, but what if my new switch is 3W+G with no neutral connection?
The current will not have parallel paths due to the fact the new system is without a neutral and having multiple 3P switches in row would not be an issue if the load is 3W+G - correct?
The utility is 2000kVA OA, 12470 pri Y 480/277v sec and the Generators are connected Y through a 3 pole transfer switch. The Gen's are not a seperatly derived system. I know if you have multiple switches in a row that you want to switch the neutral, but what if my new switch is 3W+G with no neutral connection?
The current will not have parallel paths due to the fact the new system is without a neutral and having multiple 3P switches in row would not be an issue if the load is 3W+G - correct?






RE: 3 pole transfer switches in series
Yes, I know that there are some installations where the neutral must be switched. I only do so after I make a good attempt to arrange the installation so that the neutral may remain solidly connected through the transfer switches.
If you are able to comply with the "One connection to ground" condition you may use three pole transfer switches even with four wire systems feeding line to neutral loads.
Bill
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"Why not the best?"
Jimmy Carter
RE: 3 pole transfer switches in series
Rafiq Bulsara
http://www.srengineersct.com
RE: 3 pole transfer switches in series
Alan
"The engineer's first problem in any design situation is to discover what the problem really is." Unk.
RE: 3 pole transfer switches in series