Open CT detection?
Open CT detection?
(OP)
Does anyone know of a device or circuit that can detect an open CT? I have found devices that will detect an open CT while current is flowing through it, but I need something that will detect an open CT WITHOUT current flow. The application I am designing this for is a 3 phase 1000V system.





RE: Open CT detection?
RE: Open CT detection?
RE: Open CT detection?
RE: Open CT detection?
RE: Open CT detection?
Cancel the test current out with appropriate protection settings.
Bill
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"Why not the best?"
Jimmy Carter
RE: Open CT detection?
RE: Open CT detection?
RE: Open CT detection?
Does a given CT enclose one phase of your three phase system or all three-phases?
Do you have one CT per phase?
What type of protection does this CT feed into ?
If it's a differential, then as David as mentioned, it's pretty good at detecting open already, but does rely on primary current flowing. If this is not acceptable for you (assuming it is a differential), you'd want to add your test current flowing through CT's on both sides of the zone which accomplishes same thing as system current... will trip if one of CT's opens.
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(2B)+(2B)' ?
RE: Open CT detection?
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(2B)+(2B)' ?
RE: Open CT detection?
You could easily detect an open CT circuit by measuring the voltage across the secondary terminals of the CT and tripping the breaker at some voltage set point. Obviously this would only work if there is current flowing in the primary.
Are you sure this is a requirement and not just someone's interpretation of said requirement?
RE: Open CT detection?
RE: Open CT detection?
RE: Open CT detection?