Today is...
Saturday, April 21, 2018
Welcome to, the global online
community of automation professionals.
Featured Video...
Featured Video
EtherCAT with CTC’s master lets your multivendor network play well together...
Our Advertisers
Help keep our servers running...
Patronize our advertisers!
Visit our Post Archive
How Many Devices in Serial on a Set of CT
We want to add some measurement devices at the secondary of a set of CTs. Is it possible without perturbing the measurements?

Hello folks,

I work on a new power plant project. We are looking to add some measurement devices on a set of CTs (secondary side of course) which are already use for different purposes. (protection, SCADA etc...)
I am wondering if this can induce some problems, like falsifying the measurments. Cause as far as I know, if we increase the line length it will increase the line impedance which is probably not so good to get accurate measurement values.

Thank you


If you check your CT secondary terminals you will be able to tell the number of cores. Mostly multi core CT's are used with maybe two for measurements and two for protection. If you are lucky you might find a spare core on on your CT you can use that one. If not check on the rated burden on the CT name plate and compare with the load you are trying to connect. Try not to use the protection core for your measurements.

I think one of the parameters on the CT label is Burden, that indicates how much load in series they will handle.