Here’s a quick list of rules for those who own control units. These are delicate electronic devices that are generally designed to be hung, wired, and programmed once in their lifespan, and only tested periodically. They aren’t designed to take abuse, and are easy to destroy.
- Never, never, NEVER, under any circumstances, power your panel up on battery power alone, without first applying AC power. This is bad for the charger/power supply circuit, and WILL eventually cause damage. It may seem harmless if done once or twice, but that’s all it could take. Is it worth the risk? Get yourself a power cord and do it right.
a. Plug the panel in without the batteries connected.
b. Wait for the panel to start and the software to load (if applicable).
c. Wait for the “AC power indicator” to illuminate, and for the system to indicate a battery trouble.
d. Carefully connect the batteries, observing polarity. The battery trouble should clear.
For resound systems, set the trouble silence switch back to the normal position.
I did this once on a 4002, hooked the batteries back up before the AC power, and sure enough, I blew several fuses on the board. Just took one shot. I think powering up my 4004 on batteries before AC is what killed the charger. When powering down, disconnect the batteries first, then the AC power.
- Don’t buy, power up, or try to wire a panel unless you have and understand the diagrams and technical manuals. There are a few great resources online for diagrams and technical documents for control units. Don’t “tinker” with the zone connections if you’re unsure of what you’re doing. Some systems have auxiliary outputs for the zones next to the zone loop terminals. Accidentally backfeeding panel voltage into a zone, just once, could destroy it. I destroyed both of my Miniscan 112s by “tinkering” with the supervisory zone terminals, only to find out after looking at the manual, that the supervisory connections are normally closed, unlike the zones. Why buy a panel, only to find out you need certain devices, or an external programmer that you don’t have access to? Why buy a 12-volt 5110XM panel and a number of 24-volt signals, without knowing the difference? (Yes, there’s a reference to someone here.)
- If you have a card-based system (Simplex likes to do this), NEVER disconnect or insert cards with power applied to the panel. Always power the system down, plug the cards in, then power it back up. This applies to monitor cards, signal cards, suppression/disconnect cards, whatever you have. A tech killed a 4005 by inserting a zone monitor card with the panel powered up. Only had to do it once. If you have a 2001, which is a modular system, hold in the reset button when removing and inserting cards. if you have a 4207/4208, you can usually turn the reset keyswitch to kill power to the system.
- Only strip enough wire for what you need. Modern systems have clamp-style screw terminals so that open-end spade connectors or hooked ends of wire (not preferred) aren’t necessary. You only need to strip about 1/8" of insulation from the wire. When you insert the wire into the terminal clamp, no copper should be showing, insulation should go underneath the clamp a little bit. Bare copper here is an excellent spot for a short circuit. When you strip the outer insulation from the cable, be very careful not to nick the insulation on the inside wires – it’s VERY easy to do. The best way is to use an oversized hole in a pair of wire strippers, use the strippers to make a “ring” around the cable without actually piercing the insulation, and pull it off with your hands. Then pull back the foil shield (if it’s there) and trim it off. If you can’t pull the insulation off, grip it with the strippers in a new spot that isn’t cut, and gently pull. The hole for 10 AWG wire works excellent for removing the outer insulation from 18/2 fire alarm cable. To prevent a ground fault, wrap the area where you cut the foil in electrical tape.
- Use strain reliefs and bushings in panel knockout holes. the inner edges of those knockouts can be jagged and are good spots for short circuits and ground faults. If you’re using EMT conduit, ream the inside edge with a file or the handle of a pair of pliers (an old electrician trick, works great) so that you don’t feel any sharp or jagged edges. Use a setscrew fitting and a plastic threaded bushing for conduit that terminates in open air. For conduit that terminates in the panel or junction boxes, use a plastic threaded bushing inside the panel or j-box for the remainder of the fitting threads.
- If your panel is used, carefully clean it out before setting it up. A lot of times, panels are surface-mounted to walls, and holes are cut in the back of the panel for wires. When this is done, there’s a small jagged metal disc left behind, and a bunch of metal shavings, somewhere in the world. They may be in a junkyard in Phoenix, Arizona, or they may be in a scrap metal yard in Tennessee, or they may be on the floor in a dusty electrical room where the panel was once hung. Or, they could still be in your panel, touching the circuit board somewhere. They could have been in the bottom of the panel when it was hung, but in shipping, could have been shaken around and lodged between the board and chassis. It takes a minute to look.
- Just a recommendation, but not critical: use good batteries. Panels aren’t meant to charge old, worn, or defective batteries. Batteries that have sat while discharged are usually damaged because of battery sulfation. Because batteries in series are charged at the same amperage, you should use two batteries from the same manufacturing date and lot (indicated by a stamp on the battery). An older battery will have a different internal resistance than a newer battery, and one of the two may demand more charging current. If a higher charging current is forced into the other battery, you could destroy it, it could corrode and leak… or whatever. and be careful, that’s a very corrosive acid in there. Periodically check the batteries for leaking and corrosion (corrosion indicates acid leakage. panel batteries are sealed and should NOT corrode - if the terminals corrode, it’s physically damaged and must be replaced). Check the charging voltage periodically. As a general rule, 26 to 28 volts is good. For a 12-volt system, 13.5 to 14.5 volts is good.
- And finally… just be careful. Always power the system down when making connections to the panel. you may know that you’re hooking up to the right zone terminals, but, you could still do something - touch a wire somewhere it shouldn’t touch, like a circuit board, or you could drop something, or your screwdriver could slip and make a connection you didn’t want. Check and double-check your connections before powering up. Know what the amperage rating of your signal circuits are, and make sure you don’t exceed that. Understand that just a brief short can kill the panel, and the magical blue smoke means you’re out of luck.