4002 Freak Out

As some of you know I own a Simplex 4002 that was torn out of my old elementary school during an upgrade. The panel was fine at removal when I tested it it was fine as well, and it has been fine until it tested it today, planing to finally get around to making a video about it.

I went and pulled the pull and the system went into Alarm as expected, then before the first march time pulse could finish the panel reset, as if it were in walk-test. It then since I didn’t reset the pull in time went back into alarm and acted like before, I then pulled the plug.
(Seen here: https://youtu.be/SzBiBjiFl-4)

Here is my programming and wiring for the panel: 4002 issue - Album on Imgur

Here is it powering on. I doubt this will be of any help: https://youtu.be/3HPiEqgSWRA

In the Imgur post I have attached the programming reference I am using from the field wiring diagrams.

Thanks for any help!

Just so you know, the resistors look bad as I will eventually be using them behind devices and I didn’t want to clip them. I have a bunch but with all the RadioShacks closed other then this small one that dosent carry any electric components it’s hard to get these sometimes. THEY ARE NOT SHORTED!

The 4002 is quite susceptible to spikes generated by signal devices. That old bell probably does not have suppression built in as newer versions have. The bell probably is sending spikes into the panel when the contact opens and the magnetic field collapses on the coil. This causes the CPU to reset. A 39 volt MOV installed inside the bell mechanism across the coil may fix the problem.

There was a version of strobes back then that could restart a 4002 if the first strobe was closer to the panel than 50 feet of wire.

Here is a bell mechanism with the MOV factory installed directly across the coil.

I pulled the bell mechanism out and it appears to have the MOV installed (see picture).
Although the wire run is less then 3-5 feet, I wonder if that could be the issue, as thinking back to how the system was setup there was no bell for at least 75-100 feet from the panel. Later I’ll try putting a 4903-9236 electronic horn on the panel. Could the really short wire run be the issue? The voltage spike back into the panel does make sense. This is of no relation to the issue, what strobe is able to cause the panel to restart so I can avoid it?

Yes, a longer wire run could help, especially twisted/shielded cable. It adds capacitance which can damp out the part of the spikes the MOV doesn’t clip off. That was one of our tricks back in the day for the strobes that caused a problem.

I don’t remember or have a reference for the strobe model numbers but they were early version ADA strobes.

I did find the old FSB that offered these solutions for the problem strobes.

The wire-wound resistors in the FSB work as a choke coil which has impedance to the sharp edge of the spikes.


Subject: 4002 Fire Alarm - Corrections to the ADA Strobe Circuits

Replaces FSB-568 dated January 9, 1996. Revised sections of the FSB are in italic.

ADA strobes can cause the 4002 Fire Alarm Control Panel (FACP) to reset after going into alarm. This condition often occurs when ADA strobes are mounted close to the 4002 FACP (approximately 20 feet or less). You can correct this problem in one of two ways.

Add a 208-9028 Isolated Loop Circuit Protector to each ADA strobe circuit connected to the 4002 (see illustration below).


Install a 2-ohm, 50 watt wire-wound resistor (Part No. 382-122) or a 3-ohm, 50 watt wire-wound resistor (Part No. 382-090) in series with each leg of the ADA strobe circuit.[/i]


Ok, I believe this is the issue, I also just remembered one thing, the NAC on the 4002 only had one device on it, a 4009 NAC extender, which then had the bells and strobes, it may of been the installers way of getting around this issue. Thanks a lot, will update when I get a different device installed.

Today I got around to testing it with the -9236, all went well, the issue was the bell.