One CT - two different sources

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Joined: Thu Feb 22, 2018 5:17 pm

One CT - two different sources

Post by Bodoelectric » Thu Feb 22, 2018 5:25 pm

A customer of mine asked me if he could use one set of CT's to measure both street power AND generator power. I wasn't sure how to answer because at some point - whether the utility power came back and the house was on generator or the utility power was normal and the generator was being exercised - it's conceivable that both sources would be live and likely way out of sync with each other. Will it drastically affect the accuracy of the CT to have both sources live even if only one source is actually supporting the load?

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Re: One CT - two different sources

Post by Jameson » Fri Feb 23, 2018 12:03 pm

Yes, this could work in theory.

By definition your generator's electricity and utility electricity should either not both be on at the same time, or they should be in sync. Either there is a disconnect so that your generator does not feed power to your home at the same time as the utility, or an inverter is used to sync the frequency of your generator to match that of the utility. It is similar to how a grid tied solar inverter works.

Our meter could be on either the utility, or the generator, or the combined line that comes from the utility/generator.

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