Can I use the same CT for Main & BK Protection?
Can I use the same CT for Main & BK Protection?
(OP)
Could any online expert tell me if I can use the same CT for Main & Backup protection for Transformer?
As I think the Main & Backup protection should use different CT. But I have not enough sets of CT in current Transformer. I don't know if there is a standard shows Main & Backup protection shouldn't use the same CT?
Thanks for your help.
As I think the Main & Backup protection should use different CT. But I have not enough sets of CT in current Transformer. I don't know if there is a standard shows Main & Backup protection shouldn't use the same CT?
Thanks for your help.






RE: Can I use the same CT for Main & BK Protection?
RE: Can I use the same CT for Main & BK Protection?
RE: Can I use the same CT for Main & BK Protection?
RE: Can I use the same CT for Main & BK Protection?
Depending upon availability, security and reliability standards, using a single set for two similarly applied relays should be carefully scrutinized. The relatively small cost compared to the protection investment does not sound like a very economic decision.
The incremental cost of a set of CTs seems minor and a relatively small portion of project cost. One forgotten shorting screw could make a real mess of everything.
Modern multifunction relays are wonderful and can give a lot of bang for the buck, but please don't shoot yourself in the foot.
RE: Can I use the same CT for Main & BK Protection?
RE: Can I use the same CT for Main & BK Protection?
I know of a simple, low cost item that will provide backup for the entire protection scheme from CT to interruptor without relying on DC power. They are available in a variety TOC curves that can be coordinated with your primary protection. Fuses still have their place.
RE: Can I use the same CT for Main & BK Protection?
RE: Can I use the same CT for Main & BK Protection?
Boy Howdy. 10-4 stevenal.
RE: Can I use the same CT for Main & BK Protection?
Bung
RE: Can I use the same CT for Main & BK Protection?