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Joined: Jul 2004
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If the above sequence is correct, then I would look for other problems besides the relay board.
1) Did anything happen to door electromagnet. Physical abuse, excessive water get into it, was it replaced, etc.
2) Did something happen to the door? Removed and replaced, door changer closed, ran into by a large cart, someone removed the mating magnetic plate, etc.
3) Does the electromagnet have the correct resistance, does it draw the correct amount of current, are the connections secure, etc.
4) Did someone touch the wiring between the electromagnet and the alarm panel? Did any other work get done recently that could have affected the wiring? Are the wires in the alarm cabinet in good shape, could a wire been broken, etc.
5) Is there fuse in the circuit that could have blown?
A simple continuity test and an amp draw measurement on a good electromagnet and then repeated on the suspect electromagnet, could answer a bunch of the questions.
LarryC
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Joined: Feb 2013
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Just a thought. Being its a FA panel isn't anyone concern that by "field modifying" it is voiding the panel listing or is it going to get reevaluated by the listing organization?
What about just replacing the board in question? I know it sucks to throw out so much for so little. However that's what a customers signs on for with such high tech equipment. One if my biggest gripes about techie equipment and the industry in general. Excellent question and one I had thought of myself. On Friday I contacted a Canadian Siemens rep who deals with Fire Alarm Systems. He said that modifying the circuit board would definitely warrant having it re-certified either immediately or during the next inspection.
A malfunction at the junction
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Dwayne
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Joined: Feb 2013
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Have you cut open one of the bad relays and looked at it. The problem might be obvious. I am not sure I understand tho. What fixes it, a new relay or a new board? The driver that picks the relay may be shorted so it is picked all the time. If you can get the cover off the relay you should be able to see that. Haven't tried that but if time permits I will try cracking one open Monday.
A malfunction at the junction
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Dwayne
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Joined: Feb 2013
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If the above sequence is correct, then I would look for other problems besides the relay board.
1) Did anything happen to door electromagnet. Physical abuse, excessive water get into it, was it replaced, etc.
2) Did something happen to the door? Removed and replaced, door changer closed, ran into by a large cart, someone removed the mating magnetic plate, etc.
3) Does the electromagnet have the correct resistance, does it draw the correct amount of current, are the connections secure, etc.
4) Did someone touch the wiring between the electromagnet and the alarm panel? Did any other work get done recently that could have affected the wiring? Are the wires in the alarm cabinet in good shape, could a wire been broken, etc.
5) Is there fuse in the circuit that could have blown?
A simple continuity test and an amp draw measurement on a good electromagnet and then repeated on the suspect electromagnet, could answer a bunch of the questions.
LarryC
Unfortunately I was asked to get involved after the issue was resolved. And as with so many things I work on day-to-day this is another area where I haven't had much experience. Since I didn't know much about this system I've been researching and looking it over when I had a chance last week. Of all the questions you asked I do know the following: (1) 2 of the door magnets were weak before the issue with the module began and I replaced the one that I was asked to replace after the issue was resolved. (2) The electrician who resolved the issue did not sound certain why the original module failed and why 3 subsequent replacements were "shorting out". He mentioned tracing the circuitry on the 120V side and said there was some confusion with the neutrals (he may have switched the neutrals - not certain). In the end, something corrected itself but he is not sure what that something was.
A malfunction at the junction
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Dwayne
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Joined: Jul 2004
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From my field service days, take all history with a grain of salt. People make mistakes and don't necessarily own up to them. Just like the residential guys who align the cover screws in certain orientation to detect when other fingers get into their work, "helpers" don't always own up to their deeds.
I am glad the issue is fixed. If you have a chance, I would still measure the current draw and just hold on to that number.
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Joined: Mar 2004
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From my field service days, take all history with a grain of salt. People make mistakes and don't necessarily own up to them. Just like the residential guys who align the cover screws in certain orientation to detect when other fingers get into their work, "helpers" don't always own up to their deeds.
I am glad the issue is fixed. If you have a chance, I would still measure the current draw and just hold on to that number. This is good advice.
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