B Phase CT on the Load Side , A & C Phase CT on the line side of bkr
B Phase CT on the Load Side , A & C Phase CT on the line side of bkr
(OP)
Dear all,
Does anyone know why A and C Phase CT located on the line side of the main breaker (Polarity towards the top of the breaker) and the B Phase CT located on the load side of the main breaker (polarity towards the bottom of the breaker)?
I've never seen this application before. Please let me know if anyone has any experiences with regards to this design.
Thanks
Does anyone know why A and C Phase CT located on the line side of the main breaker (Polarity towards the top of the breaker) and the B Phase CT located on the load side of the main breaker (polarity towards the bottom of the breaker)?
I've never seen this application before. Please let me know if anyone has any experiences with regards to this design.
Thanks






RE: B Phase CT on the Load Side , A & C Phase CT on the line side of bkr
old field guy
RE: B Phase CT on the Load Side , A & C Phase CT on the line side of bkr
Bill
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"Why not the best?"
Jimmy Carter
RE: B Phase CT on the Load Side , A & C Phase CT on the line side of bkr
RE: B Phase CT on the Load Side , A & C Phase CT on the line side of bkr
If this is true on your gear, that would explain the reverse polarty.
RE: B Phase CT on the Load Side , A & C Phase CT on the line side of bkr
Probably to do with the phyiscal size of the CT
RE: B Phase CT on the Load Side , A & C Phase CT on the line side of bkr
On LVCB's that have smaller CT's they can be mounted on the Line Side in the same physical direction,and they will have the same polarity.
The reason that yours is different is due to the size of the CT's and the physical spacing between the Line Side Primary stabs.
If the physical spacing doesn't exist between the Line Side Bus Stabs then you can install the CT on the Load Side Bus Stabs, but you must reverse the CT'S polarity.
You can reverse the polarity by physical flipping the CT or by reversing the secondary wiring from the CT.
If you do not have the same polarity for all your CT'S the trip unit will trip the LVCB when you bring up load.
As pointed out by others this is a typical installation.