Tapping a Starter or Breaker for CPTs

[designer82]

When they tap a 3PH starter or circuit breaker for control power transformers or any other transformer for auxiliary loads, how do they actually make the bus tap? with a multi lug connector bolted to the bus?

 

[Jraef]

Depends on a number of things. If there is bus bar after the breaker you can drill and tap it. If it is wire, you can use splitter blocks, or get some breaker lugs with listed tap-off screws on them. Some starters have tap points on the line lugs. Lots of different ways to skin that cat.

 

[designer82]

do they make these taps line or load side, usually?

 

[Jraef]

1

 

[designer82]

I'm trying to tap this starter like shown. Have you seen this done? Maybe there's issues against doing this

I could even tap it ahead of the breaker and add another breaker, it doesn't matter.

 

[Jraef]

I'm trying to tap this starter like shown. Have you seen this done? Maybe there's issues against doing this

I could even tap it ahead of the breaker and add another breaker, it doesn't matter.

Almost all combination starters are done that way. usually the tap is done on the line side of the starter (contactor) because they generally have lugs on them for doing this. 4160V though, that's a different story. Assuming that's a Draw-Out breaker, it likely has tap lugs available for the breaker terminals.

 

[designer82]

Almost all combination starters are done that way. usually the tap is done on the line side of the starter (contactor) because they generally have lugs on them for doing this. 4160V though, that's a different story. Assuming that's a Draw-Out breaker, it likely has tap lugs available for the breaker terminals.

Thank you

That auxiliary tap would be a 75KVA transformer though with #1/0 conductors. Wouldn't be for control voltage, it would be for a pump motor for a chiller chilled water pump.

 

[kwired]

Thank you

That auxiliary tap would be a 75KVA transformer though with #1/0 conductors. Wouldn't be for control voltage, it would be for a pump motor for a chiller chilled water pump.

75kVA is just a little larger than the average control power transformer usually is