CT Earthing (grounding)
CT Earthing (grounding)
(OP)
I have three protection CT's (1 in each phase) in the delta loop of a star-delta starter. The original installation had the CT secondary's (s2)connected together and grounded, and the s1's are connected to a motor protection relay (MPR)
However the protection relay manufacturer's generic data sheet recommends that for star-delta starting the 3 CT's must not be grounded. How does the operation differ between grounded and non-grounded CT secondary's
However the protection relay manufacturer's generic data sheet recommends that for star-delta starting the 3 CT's must not be grounded. How does the operation differ between grounded and non-grounded CT secondary's






RE: CT Earthing (grounding)
Grounding (earthing ) of Star point of 3xCT it's safety issue only. Grounded or not are not influence on the protection functionality.
But it's very dangerous current wiring w/o grounding, please check with mnf. what is a reason.
I think it's some missunderstanding. " Must not be grounding" is not mnf. issue.
Regards.
Slava
RE: CT Earthing (grounding)
RE: CT Earthing (grounding)