Single Phase Feed to Transformer

[djdebolt]

I have an application to feed 200A 480Vac single phase (2 phases) from an MCC bucket to a single phase transformer. The MCC bucket available is a 6" bucket and is planned to be supplied with a 3 pole 200A circuit breaker. Due to space limitations and manufacturer primary wiring, I do not have access to the line side to wire the Phase A back through the Phase B Line side so all 3 poles will see load current. Is it acceptable to provide a secondary load center with 2 pole 480V OCP at the transformer location?

 

[arion]

if you post the exact reasons why such a system is needed?
you are not trying to use a 3 phase unit as 3 single phase units in paralel?
from the description it reads
two phases from a 3p 480v 200A mcc feeder
endpoint tied to the primary of a 1p transformer i assume this is a dry type indoor unit and you are trying to do the following.
combine two single phase 200A 480v feeders to create a 3phase 200A 480v source?
take this new 3rd phase and feed it back into a 200A 3phase 480v loadcenter.
you will simply do the following
overload the transformer and the two feeders and create a very bad backfeed i do not advise this route

 

[GoldDigger]

If you have two phases of a delta you have three wires and three phases (open delta). From there you could feed two single phase pots to get a new open delta. Or you could feed the open delta into a three phase transformer to get a new delta or wye.
But the open delta(s) make for poor voltage regulation and an overload on the two pots.
If instead you have two *wires* from a delta service you only have one phase and you will never get three phases from it.

 

[templdl]

I have an application to feed 200A 480Vac single phase (2 phases) from an MCC bucket to a single phase transformer. The MCC bucket available is a 6" bucket and is planned to be supplied with a 3 pole 200A circuit breaker. Due to space limitations and manufacturer primary wiring, I do not have access to the line side to wire the Phase A back through the Phase B Line side so all 3 poles will see load current. Is it acceptable to provide a secondary load center with 2 pole 480V OCP at the transformer location?

A picture on the bucket would be nice.
If I can make a wild guess what I picture and what you are trying to do is to feed you 1ph transformer from a 6" bucket with 3p200at breaker which is mounted horizontaslly. To supply power from the 3,p breaker to a 2ph transformer simply supply the transformer missing 2 of the load side poles. No need to make it more complicated than that which I think that you are trying to do. Also, the bucket should be removable anyway which you don't need to do to remove to access the load end terminals.
See once you did not include the KVA of a 1ph transformer I would like to understand th as t the 200a breasker's is correct for the primary of this transformer.
Please not that if is difficult to provide a specific and detailed answer when the information as provided is not very detailed asnd specific wher any response that has been provided is not correct for the actual application.

 

[iwire]

I do not have access to the line side to wire the Phase A back through the Phase B Line side so all 3 poles will see load current.

No reason to do that, use two poles of the three pole breaker and leave one unused.

The breaker will work fine, it does not need to see current on all the poles.