Paralleling ct's of two circuits into one meter
Paralleling ct's of two circuits into one meter
(OP)
My question is can I meter two three phase circuits with 200:5 cts. with one form 9S meter? Will these cts be additive.
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Paralleling ct's of two circuits into one meter
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RE: Paralleling ct's of two circuits into one meter
Gunnar Englund
www.gke.org
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100 % recycled posting: Electrons, ideas, finger-tips have been used over and over again...
RE: Paralleling ct's of two circuits into one meter
David Castor
www.cvoes.com
RE: Paralleling ct's of two circuits into one meter
Bill
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"Why not the best?"
Jimmy Carter
RE: Paralleling ct's of two circuits into one meter
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(2B)+(2B)' ?
RE: Paralleling ct's of two circuits into one meter
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(2B)+(2B)' ?
RE: Paralleling ct's of two circuits into one meter
I believe that the spec on metering class CTs is to maintain acceptable accuracy at rated burden and 200% current.
Saturation is an issue with protection class CTs. Acceptance testing includes checking saturation voltages to verify acceptable operation at anticipated fault current levels.
Bill
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"Why not the best?"
Jimmy Carter
RE: Paralleling ct's of two circuits into one meter
Metering class CTs are designed to saturate to protect the meter from high secondary currents in the event of a through-fault.
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RE: Paralleling ct's of two circuits into one meter
The more direct calc (instead of doubling impedance) would of course be:
Va = Ia * Za_unshared + (Ia + Ib) * Za_shared
Since Scotty mentioned protecting the meter, it brings to mind a question what kind of thermal limit the meter input has? (and could it be challenged?)
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(2B)+(2B)' ?