Transformer Delta Nuetral?

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blue302

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I am working with a trans. that is 208 primary and 277/480 secondary,3ph Delta-Delta. I need a nuetral for some of the 277v loads. The trans does not have a X0 connection. The service that the trans is fed from is 3 ph 4 wire 120/208 and is close by. I have not dealt much with this type of transformer, but from reading some posts it appears that I might be able to derive a nuetral? If so how would I accomplish this.I do need the 480v 3 PH without a nuetral for some loads, I only need a nuetral for some 277v single phase loads. Thanks for any help.
 
I am working with a trans. that is 208 primary and 277/480 secondary,3ph Delta-Delta. I need a nuetral for some of the 277v loads. The trans does not have a X0 connection. The service that the trans is fed from is 3 ph 4 wire 120/208 and is close by. I have not dealt much with this type of transformer, but from reading some posts it appears that I might be able to derive a nuetral? If so how would I accomplish this.I do need the 480v 3 PH without a nuetral for some loads, I only need a nuetral for some 277v single phase loads. Thanks for any help.

You have contradicting information. A 277/480 volt transformer is a wye connected transformer. The voltage is 277 volts phase to neutral and 480 volts phase to phase. If you do not have a neutral connection I would suspect it is a delta connection on the secondary. If it is delta you can not get a neutral. You could install a single phase 480 volt to 277 volt transformer for you single phase loads.
 
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The fact that your service has a grounded (neutral) conductor has no impact on if you can or cannot get a neutral on the secondary of your transformer.

As Bob said, the information you gave is not helpful. The correct answer depends on what your nameplate actually reads.
 
Blue,
You might investigate a 'ZigZap' autotransformer connected between the Secondary Delta Phases. This would provide a 'neutral'. This is not a 'natural' neutral,
and has some limitations.

Why would you want a neutral on a Delta Secondary? 277 lighting?
You might investigate using an additional transformer for your system,
which could provide a 277 WYE secondary, which does have a proper neutral.

Please bring back more questions along this line.
There are engineers here who can provide insight into these interesting topics.

Hope you find this forum stimulating ...
 
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