I’m having an issue with an EST 2 with an internal ground fault. We replaced the 2MCM, Power supply, and LCD. Same internal ground fault. The SLC shows no ground fault in status only shows one ground on the panel. MCM took database no problem, and mapped perfectly as well. All devices work, as with NAC, and Annunciator. We also replace the batteries. any help would be greatly appreciated.
Jack
Does the ground dissappear when you remove all field wiring from the MCM and the PPS? If not, remove it all then power it down and back up, still there?
Is this a new issue on a system that has been in service for years? The 2 is EOL now.
Many years ago the 2’s were notorious for phantom ground faults. The solution (and yes released via a tech bulletin) was to take 2x 1 megohm resistors, one side of one to positive battery and one side of the other to negative battery, other side of both tied together with a jumper wire to ground. If it truly is a phantom ground it will clear it and a true hard ground on the slc somewhere will still display at the panel.
It should also be said that often with the 2 if the ground is on the back side of the module you will only see the 005 system ground. The newer systems are better about giving you the system ground AND a trouble on the module it’s happening on.
I’d also like to give you an example of how fickle the ground fault issues are on the 2.
I had a courthouse we fought with for YEARS. This system had many t taps. I spent 2-3 weeks at one point eliminating taps and leaving them off for a day or two at a time while combining a list of which pairs triggered a ground fault over those times. Made no sense, whatsoever.
We got fed up and threw an EST3X on a free standing rack we built temporarily and moved all the wiring to it. Literally sat and ran for 2+ months without a peep. Not the first ground fault trouble ever.
TheESTGuy,
Thanks for the quick response. I will give it a try and keep you posted on the results
Sounds good. I try to check the forums atleast daily.
Thanks for the info, it did clear the internal ground fault, but it created another issue, we now have the monitor light lit, and the trouble contacts on the MCM are closed. When we did a status, we showed everything at 0 including monitor points. Any ideas?
When looking at the main screen. Is AP @ 0?
Does this go away when you pull the resistors off?
We removed the ground wire, and the monitor light was still lit. we did not remove the resistors from the battery terminals.
Pull it all off. Cycle power - See if it’s still there… Also hit status and scroll through and see if anything is off normal there.