SEL- which give BF protection?

[mbrooke]

Apologies ahead of time if this is not the right place to ask, but I figure one of you would know. What SEL differential relays intended for transformer protection also provide breaker failure? I'm not getting much info from SEL's site.

 

[mivey]

Apologies ahead of time if this is not the right place to ask, but I figure one of you would know. What SEL differential relays intended for transformer protection also provide breaker failure? I'm not getting much info from SEL's site.

387, 587 will. would have to look for others. easiest to call rep for specifics.

 

[Bugman1400]

387, 587 will. would have to look for others. easiest to call rep for specifics.

I don't think the 387 or 587 provide specific BF protection like the 400 and 700 series relays. However, you could achieve BF functionality by using a timer and latch which is in most SEL relays, old and new.

 

[mbrooke]

387, 587 will. would have to look for others. easiest to call rep for specifics.

I looked at the manuals, nothing specific in them, especially the 587 which seems to be out of the question in terms of BF.

 

[mbrooke]

I don't think the 387 or 587 provide specific BF protection like the 400 and 700 series relays. However, you could achieve BF functionality by using a timer and latch which is in most SEL relays, old and new.

I am familiar with the BF on 487e and 787 relays, but have no clue how to set it one say a 587 which seems impossible to me. As is OUT 101, OUT102, ect all seem to be dedicated to the breaker functions (trip low, trip high side and 87 lockout).

 

[Bugman1400]

I am familiar with the BF on 487e and 787 relays, but have no clue how to set it one say a 587 which seems impossible to me. As is OUT 101, OUT102, ect all seem to be dedicated to the breaker functions (trip low, trip high side and 87 lockout).

Protection schemes that use a 587 relay typically have a backup OC relay like the 551 that also perform a BF function via timer and latch.

 

[mbrooke]

Protection schemes that use a 587 relay typically have a backup OC relay like the 551 that also perform a BF function via timer and latch.

How would I go about this though? As is all the out/in contacts are used, unless I simply trip both breakers on differential via OUT1 and OUT 2 while reserving the normal 87 trip (OUT 3) for BF trip?

 

[mivey]

I don't think the 387 or 587 provide specific BF protection like the 400 and 700 series relays. However, you could achieve BF functionality by using a timer and latch which is in most SEL relays, old and new.

that's the ticket.

 

[mbrooke]

that's the ticket.

Any idea how to set those timers?

 

[Bugman1400]

With using a 587,
OUT1=TRP1
OUT2=TRP1
OUT3=XT
OUT4=XT

X=whatever is in the MTU1 eqn.
TXPU=15 cycles (or whatever typical BF timer your utility uses)
TXDO=9 cycles

 

[mbrooke]

With using a 587,
OUT1=TRP1
OUT2=TRP1
OUT3=XT
OUT4=XT

X=whatever is in the MTU1 eqn.
TXPU=15 cycles (or whatever typical BF timer your utility uses)
TXDO=9 cycles

Thanks