Hello everyone!
In our power plant, we have three black start diesel generator (BSDG) with the generator's protection, control and metering being handled by GE SR489 protection relay and Siemens s7-400 (or so ) PLC.

The SR489 relay on BSDG 3 control panel display has been blank (not showing anything) even though there was control power on H11 and H12 and this caused the alarm "Self test fault" to show (and unable to be reset) on the simatic touch panel (HMI).

We are currently stucked on the next step (though the relays on the other two units - 1 & 2) are functional, BSDG 3 is presently the most reliable unit in the station as it stands. Any help in this regard will be much appreciated

 

Hi

Is there a message code warning **

 

Not at all
Just an alarm code which is interpreted as "Self test fault"

 

@Matthias Oduh,

Can you tell us what you've done to try to resolve the issue? You say you are stuck for the next step, but we don't know what the previous steps were (it seems a voltmeter was used to verify the mains power was present at the mains power terminals, H11 and H12.)

Is there an "easy" way to cycle the mains power to the SR489 relay? (Because you haven't told us what you've done, I needed to ask this question.)

What does the manual for the SR489 relay say about the "Self Test Fault"? Could it be a relay that changes state when the relay senses it has an issue, and that relay output is connected to the Siemens PLC?

Is/Are there any internal fuses which can be manually checked and replaced if necessary?

What happened prior to the relay display being found blank? (A plant black-out; a lightning strike; an earthing/grounding issue? (I presume

My first response would be to cycle the mains power to the SR489 relay and wait to see what happens (this, of course, AFTER having a look at the manual for the device to see if it offers any helpful suggestions). If the display remains blank and there is no indication that the "brains" of the relay are powered, then it might be time to try to order a new relay OR get a relay repair person to site to help with the problem.

 

@WTF
Thank you for this wonderful response.

Actually, we had a partial grid collapse. Unfortunately, our battery DC supply wasn't reliable and could not sustain the station for up to 10mins as at the time the collapse occur (we had to quickly resort to alternative DC supply from our PEECC to our MV/LV SWGR to be able to close our 6.6kv incomer breaker when backfeed was restored)

Prior to the collapse, we have no information regarding the functionality of SR489 relay - it was after we were called by our Operation department when they wanted to test the availability of the BSDG after the backfeed was restored that we found out that the SR489 has gone blank.

Immediately, we tried the following:
First check the availability of the Control power (which turns out possible)
Recycle power to the relay

The above were how far we could go.

To add, from the manual the relay R6 responsible for this alarm is a fail safe relay and what can trigger the relay according to the manual is "either there was loss of control voltage or an internal issues".

Thanks for the reply once again

 

Good luck