Siemens Pyrotronics System 3-Trouble Alarm on Power Restore

I’d like to know if this is normal. I’m working on a Siemens Pyrotronics System 3 installed in 1977.

After power loss the unit runs on batteries fine. On power restore the unit rings the trouble alarm, and

some poor sop has to wake up to silence it.

Is this normal behavior?

A photo of the exact unit is at:

Hi! I believe the trouble buzzer should only sound on AC restore if there is a trouble in the system. If the trouble light is burnt out (which is very common on these), there may be a system-wide trouble such as a ground fault and you wouldn’t see it. Best way to check is to meter the trouble relay contacts. I have a CP-30 manual somewhere and can get you the terminal numbers as soon as I find it.

Yes, that sounds right. There IS a system wide trouble on this panel.

The CP-30 audible trouble yellow LED is always lit. The yellow neon trouble bulb is burnt out. All the individual zone trouble indicators work fine.

This apparently started happening after a lightning strike. So the power loss must be resetting the panel and re-reporting the trouble.

I have Pry-A-Larm 315-021302 Install and Maintenance manual, but it’s rather shy of pinouts or schematics. I’ll post separately about the CP-35.

Any tips you have on troubleshooting a panel-wide trouble (when the zone troubles are fine) would be a great help!

Disconnect all the wires except for the 120V power and the battery backup. Be sure you label each one. Stick end of line resistors on all the zones and NACs. If the panel is still in trouble after that, it is probably an internal fault. The next thing you can do is power down the system completely and disconnect all of the expansion cards so that the main cpu is the only thing left. If it is still in trouble, time for a new panel.

Your System 3 is so old that I would recommend getting a quote from someone for a replacement, since panels usually don’t survive lightning strikes anyway.

What kind of facility is this anyway?

This is a private mountain lodge.

An upgrade to <URL url="Converting a Pyr-A-Larm CP-30 to Siemens Pyrotronics CP-35 text=“viewtopic.php?f=4&t=6325”>Converting a Pyr-A-Larm CP-30 to Siemens Pyrotronics CP-35 is possible if the right cables can be made or found.

Note the CP-30 uses 50mfd capacitors, not resistors, at the ends of lines.

There’s one more step: at the end of the expansion cards there’s a supervisory wire back to the panel.

That makes the list as far as I can tell:


  • [*]Disconnect panel zones, replace with end of line device (50 mfd capacitors in my case)
  • [*]Disconnect bell, replace with end of line resistor.
  • [*]Disconnect the expansion cards and route the end of chain wire plug directly back to the panel.
  • [*]Clear the panel trouble with the switch.
  • [/list]

    I’m unclear what to do with the BC-30 charger. The panel initiates trouble if I remove it, so I don’t know if there is some special step needed to eliminate it as a cause of the panel trouble indicator.

    End story: I replaced the CP-30 and the issue went away: the system has operated ever since.

    A loose wire on a detector head was an additional unrelated problem.

    I am new to this area. I am the recent owner of a 14 room inn with restaurant in the lower level. There is a 20 year old Siemens Pyrotronics System 3-Trouble Alarm system that needs attention. I am in Baltimore, MD. Does anyone know where I can find someone who can help diagnose and repair? Thank you. David Shapiro 410-340-8911

    Try posting a new thread.

    Likely you’ll have to call all the fire alarm people in your area, and resist their calls to replace the system.

    Replacement may be warranted, but don’t be sure of that.

    Siemens bought out Pytrotronics. Try calling (301) 837-2850 and ask for their service department.

    OP here: the described system is still working great. I had to replace two of the three neon lights (power/trouble) that’s it. But the local inspection company that deals with this panel is not great, and nobody else will test it for local fire department purposes.

    System 3 will be discontinued in October 2019 - you may want to look at replacing the panel entirely.