I got a 4050-80 light plate with a 4051 horn last weekend.
The seller noted in the description on eBay that the bulb would need to be replaced. When I got the alarm in the mail, I noticed there was a 120 volt GE bulb in there. I replaced the old bulb with a 30 volt bulb that I got today.
After wiring it up to my 4004, I was disappointed to find out it didn’t work. I think I may need to polarize it, but I’m not sure. What I’m concerned about is the fact there is a large “X” drawn on the bottom of the lens in ink, and that the socket may be defective.
That, however, is not the same problem I am having. Mine doesn’t trigger any circuit breakers or anything; It just doesn’t work. It doesn’t have a diode on it, though.
Any help would greatly be appreciated. Thanks in advance.
First thing you want to do is to put a diode on it.
Then, power the NAC and check the voltage in the socket (be careful not to touch the leads).
If you don’t have power, you likely have a bad socket, or a bad NAC.
Alright, I’ll start by picking up a diode from Radio Shack tomorrow. I know for one thing that the NAC is not bad. It was working with a different alarm before (this is my hobby system). Right now, I do not have access to to a voltage meter. I do not have a trouble when it’s wired up. I might need some help with the diode, but I’ll read what Newageserveralarm wrote and see if I understand it. I don’t want to get the polarity wrong, since both wires coming out of the socket are black.
No trouble when the lamp (without diode) is wired to the NAC indicates an open circuit. Either the socket or the bulb or both is bad. A good socket and bulb wired to the NAC without a diode would be a short circuit condition to the NAC and cause a trouble.
Diodes are easy. Having a negative on the cathode (banded end), the diode conducts. Of course the diode goes in series with the lamp. The cathode (banded end) points to ALARM- of the NAC. The diode blocks the reverse polarity of the supervision voltage and passes the alarm polarity to the lamp.
Start saving for a VOM. Even a very low priced one is a valuable troubleshooting aid.
I see. Darn, that’s not what I wanted to hear. The bulb is brand new, so I can eliminate that. So I should be getting a trouble even with an end of the line resistor? Would you recommend still trying a diode?
And yeah, I did have a new cheap meter, but when I tried to test two 12 volt batteries with it, it created a short and the wires started smoking. I’m really still learning electronics, and this fire alarm hobby is helping me to understand them better.
If the 4004 is working correctly the NACs are supervised for open circuit and short circuit conditions. Both will generate a trouble. A short circuit condition will also prevent the panel from activating the NAC. This is to protect the panel from damage.
Testing the NAC supervision is easy.
Power up panel and leave in normal supervisory (non-alarm) state.
Remove EOLR. NAC trouble? If yes panel is working.
Reconnect EOLR.
Place a jumper or low value resistor across NAC. NAC trouble? If yes panel is working.
NEVER place a jumper across an activated NAC! Panel damage likely will occur.
Any incandescent bulb is a very low resistance to the NAC so should cause a trouble.
I don’t think the missing diode is relevant at this time. Get one because you will need it to get this working once the socket / bulb conditions are corrected.
I am guessing it was an analog meter that fried. Analog meters are available at quite reasonable prices but can be easily damaged by using an incorrect range or function setting. Digital meters are more forgiving of incorrect use but are also more expensive.
Thanks for the help. I got it working today. The 4004 was not giving a trouble because a piece of metal inside the socket was not making contact with the bulb. Bending that back with a needle-nose pliers fixed it. I then picked up some diodes, and now it’s working great. Thanks again!