handheld comms radio "interference"

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zooby

Senior Member
Location
Indiana
Occupation
maint. electrician
I was shown a video yesterday of an employee keying a handheld radio (to talk) and when he did the pump for the dry fire system started running. I am going up there soon to check this out but........thoughts anyone? All I can add right now is that we do have repeaters on our radio system and from a print it appears there is possibly a radio charging station on "a" circuit involved with the fire stuff --which if true seems like a big NO. Appreciate you guys.
 
ptonsparky said:
I've heard of handheld radios tripping GFCIs so this does not surprise me.
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this building has been open about a year now but i suppose it could have gone unnoticed until now. tried going down this rabbit hole last evening and it does seem reasonable that certain frequencies could work their magic on low voltage relays and such....I think.
 
VCS.jpg So it no doubt is turning on when radio is keyed. I have a short video of my own but dont think i can put that on here. 4SQ is toggle switch for it. Panel schedule says ....compressor & general plugs. thats it for now.
 
zooby said:
I was shown a video yesterday of an employee keying a handheld radio (to talk) and when he did the pump for the dry fire system started running. I am going up there soon to check this out but........thoughts anyone? All I can add right now is that we do have repeaters on our radio system and from a print it appears there is possibly a radio charging station on "a" circuit involved with the fire stuff --which if true seems like a big NO. Appreciate you guys.
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I saw something similar last century. On a research ship there was a trawl winch below decks. If you keyed a radio, it would start doing the hurdy-gurdy.
 
TwoBlocked said:
I saw something similar last century. On a research ship there was a trawl winch below decks. If you keyed a radio, it would start doing the hurdy-gurdy.
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I reached out to "Gast" and they actually responded saying " they have seen this a few times and we may try changing frequencies and/or channels
( neither of those is going to happen) and that they are working with their pressure switch supplier. well thats a starting point for sure.
 
zooby said:
I reached out to "Gast" and they actually responded saying " they have seen this a few times and we may try changing frequencies and/or channels
( neither of those is going to happen) and that they are working with their pressure switch supplier. well thats a starting point for sure.
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Just so we're clear, based on the information you provided later, this is the compressor that starts running, not the "pump". And it's technically known as an "air maintenance device", but even sprinkler guys still call it a compressor. So, with that said, there is no restriction on having other loads served by the same circuit that serves the air maintenance device, either by code or by the manufacturer. On the other hand, we always recommend a dedicated circuit.
 
gadfly56 said:
Just so we're clear, based on the information you provided later, this is the compressor that starts running, not the "pump". And it's technically known as an "air maintenance device", but even sprinkler guys still call it a compressor. So, with that said, there is no restriction on having other loads served by the same circuit that serves the air maintenance device, either by code or by the manufacturer. On the other hand, we always recommend a dedicated circuit.
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Thanks for clarifying. I do appreciate it. I will be getting the "AMD" onto its own circuit now that we realize it wasn't. It just seems like it should be.
So looking at your occupation line.....have you seen this before?
 
zooby said:
Thanks for clarifying. I do appreciate it. I will be getting the "AMD" onto its own circuit now that we realize it wasn't. It just seems like it should be.
So looking at your occupation line.....have you seen this before?
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This particular issue, no. On the other hand, now that I know about it, I'll keep it in the back of my mind in case some sprinkler tech runs into a similar situation. The fire protection industry is pretty conservative, so moving to things like digital pressure switches takes a while. And this is an excellent illustration of why that is so.
 
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