"Battery Trouble" and "Bell Trouble" are two independent troubles on the system.
means that the system has determined that there is something wrong with the battery.
means that system has determined that there is something is wrong with the building-wide bell circuit.
You've replaced the battery, but the Bell Trouble still needs to be taken care of.
The bell circuit is also called the NAC circuit; NAC means Notification Appliance Circuit. That's the building's circuit that carries power to the horns, strobes, or bells throughout the building.
The panel is always checking the continuity of the wires in the bell circuit. To sound the alarm for everyone, in case of fire or other danger, the panel is making sure all the horns, strobes, or bells remain connected.
If a wire comes loose from a bell, or if a wire breaks, some or all of the bells won't work, so the panel is saying that this should be checked out.
If the wiring is shorted out for some reason, the panel is also calling that a "Bell Trouble". Again, to sound the alarm for everyone, in case of fire or other danger, the panel is making sure all the horns, strobes, or bells remain connected.
If there's a short circuit anywhere on the bell circuit, none of the bells will work, so the panel is saying that this should be checked out. When the panel detects a short on the circuit, the panel won't even try connecting power to the circuit, even in an actual fire.
If a wire came loose inside the panel, that is fairly easy to find. But that doesn't happen very often. Usually, the "Bell Trouble" is somewhere else in the building.
When the loose wire or short circuit can be seen when just walking around, the circuit is easy to fix. However, the wiring is usually hidden in the walls, so problems are not that easy to find.
There are two instruments useful in finding the location of the open circuit or shorted circuit: a voltmeter and an ohmmeter. The voltmeter is the best bet for finding where in the building a wire is broken, the ohmmeter is the best bet for finding where in the building a short is located.
To fix the trouble, you will have to go around the building to find it.
Pathway with Two Ends
The Bell Circuit is a loop of wires; it's a pathway that has two ends. One end of the pathway is connected to the panel, the end that originates the power. The other end of the pathway is connected to the end of line resistor. Between the two ends are connected all the horns in the building.
Check the voltage on the Bell Circuit at the panel and at the end of line resistor.
- If there is voltage (5 volts to 24 volts) at the panel, and no voltage at the end of line resistor, somewhere in between, the wire is broken. Find the break, and reconnect the wire.
- If there is voltage (5 volts to 24 volts) at the panel, and the same voltage at the end of line resistor, there may be something wrong with the panel.
- If there isn't any voltage at the panel, there is either a short in the building's Bell Circuit, or the panel isn't working right.
As far as polarity goes, the voltage on the Bell Circuit reverses when the alarm is sounding. Because of this reversal, when the alarm is not sounding, and the voltage is being measured using a voltmeter, the wire that is measured as positive goes on the minus terminal of horns and strobes, and the wire that is measured as negative goes on the plus terminal of the horns and strobes.
The trouble you are experiencing may be deeper. When more than one unrelated trouble shows up at the same time, like a battery trouble and a bell circuit trouble at the same time, sometimes you need to consider what could be in common to both troubles.
Remember. the wires for the battery and the wires for the bell circuit all are connected to the panel. The cause of the battery trouble could be:
- A bad battery
- The failure of the battery to charge because of a problem in the panel, which could also be an indirect trouble with the Bell Circuit
Then again, while changing the battery, a Bell Circuit wire could have been knocked loose. It's been known to happen, even to me.
The panel is also old, the age of the panel is also something to be concerned with.
According to what I can look up, the FIRE-LITE MINISCAN 424 panel's instruction manual is dated 1984. Often times, these older panels lasted only 15 years. However, some of them can last much longer, like this one. The problem, though, isn't really with how long they hang in there, the problem is what happens when something goes wrong with the panel.
Fire-Lite isn't making this panel anymore.
If the manufacturer was still supporting the panel (the manufacturer was still making parts for the panel), when something goes wrong with the panel, the panel can be easily fixed.
This is not a supported panel. Even if you can find parts or a substitute panel, when - not if - something else goes wrong, you may not be able to find the needed parts and the panel will then have to be replaced on an emergency basis.
It's not just the panel that needs replacement, it's the whole building wide fire alarm system that's involved. Overtime-labor costs and possible fire walks will be included in the replacement. If the panel is not replaced now, while there isn't an emergency, the panel will be replaced later, when there is an emergency.
The biggest issue with emergency replacement fire alarm systems is that you don't get to pick the best installation company or the best system, "You takes what you gets".
A scheduled replacement now is cheaper than an emergency replacement later.
The panel is getting old. My personal recommendation is that you replace the panel now. Everyone will be happier in the long run. And you will have a panel you can service more easily.