INFO ABOUT BBC INTERPOSING XFMRS FOR 87T PROTECTION 1

[parramanuel]

I'M DOING THE CALCULATIONS OF THE SETTINGS FOR THE PROTECTION RELAYS ASSOCIATED TO A 33MVA (24/13,8 kV) GROUNDED WYE AUTOTRANSFORMER.

AWE HAVE A OLD BBC D21se RELAY AS A DIFFERENTIAL PROTECTION WITH INTERPOSING XFMR FOR THE CURRENTS OF THE 24 and 13,8 kV SIDES. THE ONLY DATA THAT I HAVE OF THAT INTERPOSING XFMR ARE THE FOLLOWING..

MANUFACTURER: BROWN BOVERI CORPORATION (BBC)
Typ W1 23 DS
HE 688691
I= 8...1,2 / 5-2,8-1-0,577

FROM THIS DATA I KNOW THAT THE CURRENT OF THE CT PRIMARY GOES FROM 8 TO 1,2A AND FOR THE SECONDARY I HAVE 5;2,8;1 OR 0,577A.

I WAS TRIYNG TO FIND INFORMATION ABOUT THESE INTERPOSING XFMR BUT I DID NOT FIND ANYTHING. I NEED A MANUAL OR SOMETHING THAT CAN SHOW THE CONNECTION DIAGRAMS FOR THE PRIMARY AND SECONDARY WINDINGS AND AVALAIBLE CURRENT TRANSFORMER RATIO.

THANKS BEFOREHAND FOR YOUR HELP.

 

[slavag]

OMG, it's very, very old relay
see attached manual of this relay, maybe you found something, information about interposing CT, I think, possible found only in Baden, Swiss.
Try ask your local ABB.
I have some very old catalog of BBC, tomorrow will check.

 

[parramanuel]

Thank you for your response slavag.
Right now I'm checking the relay manual and it shows some basic information about the interposing xfmrs. I hope that you find something in your old BBC catalog.

 

[slavag]

ufff. from catalog 1982.
please find attached, sorry not best quality.

 

[parramanuel]

Thank you so much for your support. That's the information that i was looking for.