What does a CT measure?

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Multiple Choice

What does a CT measure?

A current transformer measures current, using magnetic coupling to produce a scaled current in its secondary winding that mirrors the current flowing in the primary conductor. This works best with alternating current because the transformer relies on changing magnetic flux to induce the secondary current; a steady DC current doesn’t continuously change and can saturate the core, so standard CTs aren’t used for DC. That’s why a CT on an electrical system is used to monitor AC current on the line, not voltage. It won’t directly measure AC voltage or any DC voltage. In practice, CTs provide a safe, proportional current signal for meters or inverters to monitor how much current is flowing.

A current transformer measures current, using magnetic coupling to produce a scaled current in its secondary winding that mirrors the current flowing in the primary conductor. This works best with alternating current because the transformer relies on changing magnetic flux to induce the secondary current; a steady DC current doesn’t continuously change and can saturate the core, so standard CTs aren’t used for DC. That’s why a CT on an electrical system is used to monitor AC current on the line, not voltage. It won’t directly measure AC voltage or any DC voltage. In practice, CTs provide a safe, proportional current signal for meters or inverters to monitor how much current is flowing.

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