Converting a Pyr-A-Larm CP-30 to Siemens Pyrotronics CP-35

I have a Pyr-A-Larm CP-30 panel installed in 1977 which took lightning damage and now constantly reports global trouble.

I’ve purchased a used Siemens Cerberus Pyrotronics CP-35 which seems very similar: is it possible to adapt this?

One challenge I see is the CP-30 has the module connector in the upper left corner of the board (labeled P1).

For no apparent reason, the CP-35 has the same connector located at the lower left of the panel (labeled P3).

The existing short jumper cables don’t reach unless I install the entire row of modules upside down.

Are there other gotchas? A ready source of longer module cables? Thanks.

Unfortunately the CP-35 won’t be compatible with the existing power supply or battery charger. You would need the PS-35 and BC-35. I think the rest of the modules will work but I’m not positive.

You mentioned that there’s an audible circuit trouble. Have you checked the replaceable audible circuit fuse located under the CP-30 cover? If I find my schematic which has suddenly gone MIA, I’ll pinpoint which fuse it is.

A schematic would be a big help.

I’ll be up this weekend looking at this system (which is a 4 hour drive from where I live).

I’m aware the CP-30 has an integrated power supply and the CP-35 is not only wider, but has a separate power supply.

contact mention you are a member of the forum. See if he can offer repair or replacment.

Meaning you’re recommending fixing the CP-30 main board, rather than upgrading to the CP-35?

All four fuses are good. 2 of 3 Gap caps are black but not shorted.

panel trouble persists on bare panel with just a 50 mfd cap on the main zone contacts 8 + 9.

All individual zone trouble lights and alarms function fine when hooked up.

Sounds to me like it’s time for a new panel. You should get quotes from some alarm companies for a replacement panel.

The building management has a budget of $1000 for the repair, including other needs. A used CP-30 last sold on eBay for $40 in December 2013, but present lowest price is $600.

Only $1000? You won’t be able to do much for replacing that panel with only $1000…

Trust me, it’s not worth fixing. You don’t know what else could have been damaged in that lightning strike… since the System 3 is a card based system, you could have also lost a zone or two – do all of the zones put the panel into alarm? has this been tested since the lightning strike?

Here is the deal… plain and simple.

You are not licenced. I do not care what educational background you have.

IF that alarm fails to trip and someone dies or gets hurt you will be held criminally responsible. If the building owner does not feel they need to budget for this to provide a quality and proper fix… that is on them. Do not put your self in the middle.

1,000 bucks will buy a low level conventional panel and a few hours of a licenced technicians time.

I am frankly tired of seeing people not qualified trying to fix a life safety alarm system to save a few bucks because there is no clear cut return on the investment or they think they can handle it.

The return on a few grand for a quality alarm? A life saved.

The return on a non qualified guy buing ebay parts to fix an alarm the boss is to cheap to pay for? Jail time and loosing many lawsuits.

It is very bad practice to swap out a damaged part with a used part, especially as a permanent fix.

Parts and Smarts for a conventional panel replace really shouldn’t go over your budget, unless of course they need to start replacing devices.

The lightning strike was over ten years ago. All zones trigger alarm, and all zone supervisory troubles function. I tested that myself using smoke in a can and a heat gun.

Last year a big name professional company was hired to certify this system and… botched the job… listing detectors on floors that had no detectors and missing an entire zone that had never been wired (the insulation on the panel end of the wire was not even stripped). I’ll pick up the pieces here, and at the end have a licenced firm recertify the system: but with enough client knowlege to ensure the job is done right. I appreciate the sentement regarding non-professionals touching a life safety system, but also see value in having the building representatives understand the system at least at a block level, able to properly oversee any professional work.

Oh, and if need be push back on that budget.

Note for the record that this property is in California, where a C-10 is all that’s needed to work on a FACP, a legal requirement that’s been met, sufficient or not. At least as of the records I can find, there no code upgrade on a like-for-like replacement ( <LINK_TEXT text=“ … 080910.pdf”></LINK_TEXT> ). I know other states are far stricter. The result in this case is system that covers no ducts, has no initiating devices in the kitchen, fireplace rooms, or electrical areas, no NAC on the sleeping floor, and no range hood anything. The system, even prior to the lightning strike, was underbuilt, and nothing in California code compells anything beyond adding a battery powered CO detector. That might wake the princess of the pea in a building this large, but everyone else will sleep right through.

Note: I verified the CP-35 works with the ZN-30 just fine, but requires a longer cable.

Where in California is this building at?

Nevada County.

(I found an improperly located EOL capacitor, meaning the panel always showed trouble clear on a certain zone, even when I pulled detector heads. That was not flagged in the professional inspection report either.

I ended up going removing the end detector from each zone to verify that no similar supervision flaw existed elsewhere.

That flaw was as old as the panel… 38 years… and never noticed in any prior recorded inspection).

Unfortunately that’s a bit outside of our service area, I was going to say you should have my company give you a quote for a new system see if they could cut you a deal. But no worries.


New here & this is my 1st post. I grew up on System 3 panels and have been working on Siemens equipment for 25 years. (worked for Pyro distributor then worked for the factory)

If you replace the CP-30 with a 35 you will need to move all the modules down to the second row. PS-35 goes top right, CP-35 takes up remainder of top rail. The BC-35 sits under the PS-35. You also get two new zones on the CP-35. I forget off the top of my head if the ZN-30 is a shorting zone for contact devices. Either way, the CP-35 zones will work in place of the ZN-30, so you can get rid of one of those modules.

I was just looking through an old manual I have for System 3. The CP-30 will light the trouble lamp if there is a ground fault anywhere on the system. There’s a ground fault jumper on the CP-30 to the right of P1 (a two pin connector). Remove that temporarily & see of the panel clears. If it does, there’s a ground fault. If no grounds, hold down the reset & silence buttons, remove the system buss connector from P1 to disconnect the modules and move the connector from the top left module (the one with the single wire) back to the CP-30. This will isolate the modules from the CP-30 to see if it’s a bad module or CP.

Also, the ZN-30 is NOT compatible with the CP-35, so you will need a ZU-35. Is that a ZN-31 in there too? If so, not compatible. It looks like only 4 zones, so you would just need one ZU-35.

Is there a way to upload or attach PDF’s? I can scan the cut sheet & post it (I have all the cut sheets for that panel).

Old alarm guy: yes I removed the CP-30 ground fault jumper and it did not clear. I have the original cut sheet in paper form. Since the audible trouble LED and the panel trouble are both lit, I think the fault is in the audible circuit. In the end I procured a replacement CP-30, protecting it with a really nice surge protector on the input power. For background, the owner and repair tech at says that the CP-30 fails quite easily due to lightning.

Note: the cut sheet for the CP-35 says it’s compatible with the ZN series modules. I would have tried it all, but fell down with finding the required longer cable to reach between the top row (CP-35, PS-35) and the bottom row (ZN modules). I could have made the cable using modern molex pins, but it just sounded like too much trouble.

On this building various zones should have, but did not, fail a professional inspection. I’ve now given the system an extra zone, love and attention, and a complete checkout, in cooperation with the local Fire Department. Though I stubled my way through, it’s better now. Thanks for the help.