Need help with Simplex 4051 horn

Hi. this is a very technical question, but I am having trouble with my simplex 4051. It will give the panel a trouble and shut off the NAC when ever it is powered. The diode does work, and contacts are not corroded, and the varistor was fine. I have completely rewired it, and have the same problem: whenever the contacts are adjusted down so that the horn vibrates more, the panel gets a trouble and shuts off the NAC. I think that it may be drawing too many amps, but I am not sure. Please help! Thanks

What’s the panel? It sounds to me like a Back-EMF overload.

At least MountainBell9845’s panel has a fail-safe instead of totally frying itself.

The panel is a Simplex 4008. It has a very well designed fail safe function.

Ought to check the install guide for that panel to make sure it is able to handle mechanical horns. If I weren’t on break I’d look for you.

I have ran several 9833’s and a 4041 on it. The NACs are rated at 1.5 amps each. Also, they are using solid state relays for the NACs.

THe 9833s and the 4041 draw less power and produce less interference. I have found the 4051 to be a horn that produces the worst EMF interference. Are you sure the diode on the horn works though?

Yes, I just replaced it when I rewired it

You’re sure you put in the right kind of diode?
Do you have a multimeter?

Yes; it is a regular diode rated at 1 amp. This same kind of diode has worked in this 4051 for a while, and I did check it with a meter, and it works

Check the draw with a meter.

  1. The 4051 horn also has a capacitor wired in parallel with the diode. Is this present on yours?

  2. What is the part number on the diode? (e.g. xNxxxx)

Yes, it is a black cat PKM 4pP25 .25MKD, 400VDC.