I was at a location recently where they utilize a Schlumberger type J5S meter to monitor heat loads (heat loads receive a discount). I noted that whoever did the installation had used two separate current transformers and then wired them in parallel. Is this standard practice? Wouldn't this reduce the net load calculated by the meter?
Meter / Pararllel CT connection
- Thread starter dlip
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jtester
Senior Member
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- Las Cruces N.M.
I'm not sure I understand your description of the installation. The J5S is a self contained single phase watt hour meter. It doesn't use CT's. The CT's might have been there to run another portion of the metering.
If the CT's were truely in parallel, thiier measured loads would add if the polarity was correct, but I wonder if they were really in parallel.
Jim T
If the CT's were truely in parallel, thiier measured loads would add if the polarity was correct, but I wonder if they were really in parallel.
Jim T
It's definitely a J5S and is connected with two CTs tied together in parallel right before the meter (one CT is at a remote location and that is why they are using two), and then the two parallel connected outputs from the CTs are run into the meter. It seems to me that if they were in series their measured loads would add? In parallel, when there is only current in one the impedance of the other would attenuate the measured load - right?jtester said:
The CT's generate a current according to the amount of current flowing through them. So if they are wired in parallel, the currents would add together.
It sounds like one CT is around one wire going to one load, and the other CT is around another wire going to another load. So the CT's are measuring the total energy used.
It sounds like one CT is around one wire going to one load, and the other CT is around another wire going to another load. So the CT's are measuring the total energy used.
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