Dale001289
Senior Member
- Location
- Georgia
Has anyone out there 're-set' a SEL-751 protective relay after a fault or temp power outage? I always thought the functions would 'auto-reset' once power was restored.
You are using an out of date browser. It may not display this or other websites correctly.
You should upgrade or use an alternative browser.
You should upgrade or use an alternative browser.
Schweitzer SEL-751 Protective Relay settings.
- Thread starter Dale001289
- Start date
Elect117
Senior Member
- Location
- California
- Occupation
- Engineer E.E. P.E.
The settings in a 751 shouldn't be reset because of a loss of power. They required passwords to be modified and changed. The settings are usually written to the device with SEL Software.
From my memory, there is a 4 pin or a 6 pin behind the front cover that can be used to bypass the login? Maybe there is a system reset there as well?
I haven't worked on protection systems in a while.
From my memory, there is a 4 pin or a 6 pin behind the front cover that can be used to bypass the login? Maybe there is a system reset there as well?
I haven't worked on protection systems in a while.
zbang
Senior Member
- Location
- Roughly 5346 miles from Earls Court
Is this "re-set" the functionality or "re-set" the parameters? The former should happen as part of normal operation..
Dale001289
Senior Member
- Location
- Georgia
The settings in a 751 shouldn't be reset because of a loss of power. They required passwords to be modified and changed. The settings are usually written to the device with SEL Software.
From my memory, there is a 4 pin or a 6 pin behind the front cover that can be used to bypass the login? Maybe there is a system reset there as well?
I haven't worked on protection systems in a while.
Thank you for this valuable feedback
Sent from my iPhone using Tapatalk
- Location
- Wisconsin
- Occupation
- PE (Retired) - Power Systems
It de
It depends on the function and how it was programmed. There are times when you want the relay to stay in a 'locked out' condition until a specific reset command is received. This safety feature is not overridden by a simple power cycle.Has anyone out there 're-set' a SEL-751 protective relay after a fault or temp power outage? I always thought the functions would 'auto-reset' once power was restored.
I deal with 751 relays about once a week.Has anyone out there 're-set' a SEL-751 protective relay after a fault or temp power outage? I always thought the functions would 'auto-reset' once power was restored.
What exactly do you mean by reset? And is it powered by AC or DC?
All ours are powered with DC.
Also, is it the 751 or the 751A?
Go to the terminal window and type in STA to see the status results-
There is also reset breaker data- BRE R that is to reset the breaker wear
Last edited:
D. Castor
Member
- Location
- Port Angeles, Wash
- Occupation
- Electrical Engineer
Fault indicators (targets) can be retained after a fault until the TARGET RESET button is pushed. This reset button will NOT change any settings in the relay. If the relay actually loses control power, the settings are still retained in non-volatile memory. It should power back up with no need to reset anything. If there are targets on the front of the relay, you can clear them with the TARGET RESET button.
baserunner4
Member
- Location
- CA
It really depends on how the relay is configured and programmed to trip. Depending on the relay type, auto-resets are possible, but they must be explicitly accounted for in the logic.