Siemens HMS-D failures

Hey guys,

I have been getting a lot of Trouble reports of these HMS-D pull stations that “go missing” or have communication errors with the panel. (FS250, FC922 for example), I can use my DPU to test out these devices and the DPU can’t even find it. I’ve only been on service since September, and I’ve already had to swap out 5. Install ranges 1-3 years. Am I the only one with this issue? I’ve had one installed in a very humid indoor pool, so I don’t count that one.

We had a few of these "mysterious failures’ too, it turned out an electrician we had doing some work reversed the wires and the smoked the pull stations. “oh, polarity matters?” was their response.

Good luck

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Siemens labels wiring terminals with numbers instead of directly labeling them with their purpose - perhaps the intent is to get people to read the operations manual? It’s well intentioned, but backfires when people try to figure out the wiring themselves and end up breaking things.

Speaking of the operations manual, it’s available here - with a wiring diagram at the top of page 2:

You know, I’ve never actually paid attention to how it was wired when replacing. Next time one fails, I’ll check that out. Thanks for the idea!