Transformers and Lockout Relay 86, can you say you don't need it?
Transformers and Lockout Relay 86, can you say you don't need it?
(OP)
Basic question on Lockout Relay 86 and power distribution transformers used as voltage step down for industrial sites. Typical transformer sizes are from 10MVA to 500kVA with LV secondary (600V or 480V distribution).
Curious to know at what transformer size do you typically not use the relay 86? I have seen Engineers use lockout relays for 5MVA XFMRS (4kV to 600V) while other Engineers do not.
Safer is always better, but sometimes, your upstream relay doesn't have the 86.
Just like an opinion on it.
Thanks,
Majesus
Curious to know at what transformer size do you typically not use the relay 86? I have seen Engineers use lockout relays for 5MVA XFMRS (4kV to 600V) while other Engineers do not.
Safer is always better, but sometimes, your upstream relay doesn't have the 86.
Just like an opinion on it.
Thanks,
Majesus






RE: Transformers and Lockout Relay 86, can you say you don't need it?
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If we learn from our mistakes I'm getting a great education!
RE: Transformers and Lockout Relay 86, can you say you don't need it?
RE: Transformers and Lockout Relay 86, can you say you don't need it?
RE: Transformers and Lockout Relay 86, can you say you don't need it?
RE: Transformers and Lockout Relay 86, can you say you don't need it?
On the low voltage side, it is done by putting "DO Not Operate" Tags. Again, it do not guaranty idiot thing won't happen (we had an incident that a person close one DC breaker that has a tag on)
RE: Transformers and Lockout Relay 86, can you say you don't need it?
"If the 86 is operated, notify the shift engineer or maintenance engineer and let THEM decide what the next step is."
old field guy
RE: Transformers and Lockout Relay 86, can you say you don't need it?
RE: Transformers and Lockout Relay 86, can you say you don't need it?
Tagged or Tag Out is operations lock out, same as disable the scada control, it follows the utility work protection code.
Most LV breakers protection do not have a 86 function after a trip and have to be tagged before the root cause found.
RE: Transformers and Lockout Relay 86, can you say you don't need it?
What is the procedure when an upstream breaker trips, that's a different topic.
RE: Transformers and Lockout Relay 86, can you say you don't need it?
I have seen clients who required it on transformers >2500 kVA.
There has also been discussion about using a separate reset button on microprocessor relays in lieu of a separate, physical and somewhat clunky and archaic 86, but I take a conservative approach and when an 86 is desired, I specify the old, clunky thing.
old field guy
RE: Transformers and Lockout Relay 86, can you say you don't need it?
RE: Transformers and Lockout Relay 86, can you say you don't need it?
RE: Transformers and Lockout Relay 86, can you say you don't need it?
RE: Transformers and Lockout Relay 86, can you say you don't need it?
RE: Transformers and Lockout Relay 86, can you say you don't need it?