Current Transformers

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don_resqcapt19

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Location
Illinois
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retired electrician
In theory it is infinite. The CT will produce enough voltage to drive the secondary current through the load. This is the reason the secondary circuit of a CT should never be opened if there is primary current.
 

SG-1

Senior Member
There is no way to calculate that without knowing the burden of the meter. As stated before, by Don, the CT will generate enough voltage to drive the current through the meter.

Where is the voltage being measured ? X1 to X2 ? Or across the ammeter ?

Is one side of the secondary connected to ground ?

Can you supply a link to the spec sheet for the meter ?
 

Besoeker

Senior Member
Location
UK
What is the expected voltage on the secondary side of a CT? Installed on a 480 volt circuit with CT ratio 500:1
Think about what the CT stands for. Current transformer. At 500:1 you would expect 500A in the primary to produce 1A in the secondary - provided it has somewhere to go. Ammeters are usually quite low impedance so not much voltage would be developed across its terminals. As others have pointed out, the voltage depends on what is connected to the CT secondary.

A different take. Suppose you have a 480V to 120V single phase transformer.
Can you determine the current that it will supply based on just that information? Of course you can't.
 
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