Alarm Reset SEL relay

ATSman

Senior Member
Location
San Francisco
Occupation
Self Employed
I have a SEL 351A Protection Relay and, without hooking up a loptop, is their
a way to reset the "LO" alarm. Yes I did try cycling the control power.
 

paulengr

Senior Member
It’s totally programmable. If someone did not leave a way to do it then no. I’ve made mistakes like that accidentally.
 

Macbeth

Member
Location
Livonia NY
You can not alter set-points through the display, they are considered engineering not operator set-points.
You must alter them through the software.
The software is downloadable through the SEL site for free.
With any luck the passwords are still default..
The software works like a Command Line Interface (CLI).
The hardest part is getting the DB9 to make a cable..
 

Hv&Lv

Senior Member
Location
-
Occupation
Engineer/Technician
I have a SEL 351A Protection Relay and, without hooking up a loptop, is their
a way to reset the "LO" alarm. Yes I did try cycling the control power.
I’m with Mivey here...
that’s the lockout led.
either the breaker is open or you have it some other way where the 79LO relay word bit is a “1”
 

Hv&Lv

Senior Member
Location
-
Occupation
Engineer/Technician
You can not alter set-points through the display, they are considered engineering not operator set-points.
You must alter them through the software.
The software is downloadable through the SEL site for free.
With any luck the passwords are still default..
The software works like a Command Line Interface (CLI).
The hardest part is getting the DB9 to make a cable..
The sell a cable, no need to make a special one.
 

ATSman

Senior Member
Location
San Francisco
Occupation
Self Employed
Thanks for all the replies.
Sorry for the delay. Let me supply more info.
This is a simple transfer (throw-over) scheme that employs 2 MV vacuum breakers: Utility and Generator.
The logic is controlled by 2 Multilin relays: M60 and G60 (Main and Generator) and the SEL relay which I think is for redundant protection.
A power failure occurred, generator started, Main opened and Gen bkr closed.
Utility power returned, but instead of the Gen bkr opening and the Main bkr closing the Gen bkr stayed closed
and the LO alarm showed on the SEL and Failed To Transfer showed on the M60 and G60 relays.
I don't remember what I did to reset the alarms (this happened last year) but when I did, the Gen bkr immediately opened but the Main did not close. Found out later that the close spring charge circuit failed on the Main bkr (C-H VCP .) We manually charged the springs to get the Main bkr closed.
Our next step is to repair the charge circuit on the Main bkr or replace bkr with a spare that was just received.
Can someone answer how I was able to reset the alarms without accessing the program with a laptop.
 

Hv&Lv

Senior Member
Location
-
Occupation
Engineer/Technician
Thanks for all the replies.
Sorry for the delay. Let me supply more info.
This is a simple transfer (throw-over) scheme that employs 2 MV vacuum breakers: Utility and Generator.
The logic is controlled by 2 Multilin relays: M60 and G60 (Main and Generator) and the SEL relay which I think is for redundant protection.
A power failure occurred, generator started, Main opened and Gen bkr closed.
Utility power returned, but instead of the Gen bkr opening and the Main bkr closing the Gen bkr stayed closed
and the LO alarm showed on the SEL and Failed To Transfer showed on the M60 and G60 relays.
I don't remember what I did to reset the alarms (this happened last year) but when I did, the Gen bkr immediately opened but the Main did not close. Found out later that the close spring charge circuit failed on the Main bkr (C-H VCP .) We manually charged the springs to get the Main bkr closed.
Our next step is to repair the charge circuit on the Main bkr or replace bkr with a spare that was just received.
Can someone answer how I was able to reset the alarms without accessing the program with a laptop.
To be quite honest, it’s hard to tell without the AcSELerator file. The logic can be programmed so many ways other than default.
Couple of things I noticed in your post..
The spring charge circuit isn’t in the logic? If the charge state has an IO point, it should be wired into the relay. That way you can put In logic so that the breaker won’t open without the charge spring being charged.

There is a reason the LO is a 1. Could the LO be tied to the 25 sync check also? Could have been this was a DTL event and the last time it happened it could have been some other type of event.

I would be more concerned over why the breaker opened last time when you hit reset. There should be some logic in there to make sure that doesn’t happen as it did.

Hook the laptop up. Pull a HIS, SER and an EVE from the terminal window. See what’s up with it...
 

ATSman

Senior Member
Location
San Francisco
Occupation
Self Employed
Hey Hv,
I found this:
11. Hard Reset:
A hard reset can be performed on the F60 and the G60. This will reset the logic, however if any
inputs are operating within the logic these will still be active and will still operate logic after a
relay hard reset.
To perform a hard reset on the F60: Open the Trip circuit breaker (CBTR) for the Utility breaker.
This will remove the control power from the F60. Wait 3 seconds and close the breaker. This will
cycle power to the relay. Relay will re-boot on its own. Make sure that the system is in auto after
a hard reset by checking the indicator lights in section 106.
To perform a hard reset on the G60: Open the Trip circuit breaker (CBTR) for the Gen breaker.
This will remove the control power from the G60. Wait 3 seconds and close the breaker. This
will cycle power to the relay. Relay will re-boot on its own. Make sure that the system is in uto
after a hard reset by checking the indicator lights in section 106.
It appears that the reset did come from recycling the control power to the relays.
Thanks for your help and glad to know there are people on this forum that have the same interests in my
world.
Tony
 

paulengr

Senior Member
SEL relays have a separate TR (trip) and reset logic. The internal trip code latches. A beginner mistake when programming them is to not provide reset logic. I’ve done it myself. Once you do this about the only way out is to fix the reset logic. Common methods are to clear when the breaker aux contact signals open or program a button as a reset or say the open button is dual function. The target reset button does NOT clear the trip logic and neither does power cycling. You could flash a new program but that’s just covering up a programming bug.

There are some things you can’t edit from the front panel but these are two you can change. Unlike the access terminals write permissions in SEL are all software. There are two levels of passwords and defaults in the book.
 

Hv&Lv

Senior Member
Location
-
Occupation
Engineer/Technician
Unlatch trip is generally default, but not knowing the OPs situation it’s hard to figure out what he needs to add.
I just assumed ULTR was done with a 52A or B contact the way he had it set up.

FWIW, the target reset can be set to unlatch trip.
Its “ORed” in there with some other unlatches
 

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