Oh, I did not know that.
Destin, I use to hook up 5-6 NA’s in series and nothing happened to my panel, they were all obviously the same type or similar but nothing ever happened? Why can’t we?
In series? I think you mean parallel.
I mean series, that’s when you connect POS or one device to the next and NEG to the next device, right?
Think P-P-P Plus to plus parallel, If you connect plus to the plus on the next device it is parallel.
You’re free to do what you want, but it’s not a good idea. Your panel may be more tolerant, but somehow I accidentally wired a Wheelock 34T, SAE AV32, and NS together in series and it smoked a NAC on my MS-5UD. It may have drawn too much current, but I can’t say for sure what caused it. Either way, there’s no reason to wire anything in series on a modern low-voltage panel.
5 24V NA’s in series is 120V. How the hell does that work on a 24V NAC?
Actually, five devices in series on a 24VDC NAC would each be receiving 4.8VDC. When you wire in series, the voltage is evenly divided across each device.
Didn’t quite think that through, but it still makes no sense.
When doing an upgrade you sometimes find that when you remove the wires in the terminal connections in the fire panel they have turned dark brown or black, meaning that you might not get the best no resistance contact at your new terminal connection. You can also find this discoloration problem when removing Marrette connectors in electrical connection boxes. Sometime even stripping the insulation back shows the same discoloration problem. I always carry a small 1" X 6" strip of 150 grit emery cloth with me in my tool pouch and and half wrap it around the stripped copper end and roll the emery cloth back and forth between my fingers with light pressure until I see clean, shiny copper again, so I know I will get a good no resistance connection.
Do you mean Parallel?( Not trying to show anyone up, but rather curious. 
)
Or am i not getting the point?
He’s correct.
When you wire in parallel, the amps are evenly divided, not the voltage.
Ok thanks Andrew! I probably misread something :roll:
“I don’t have a wristband grounder. Am I able to just wrap the grounding wire that comes with the hot and neutral in AC power? I don’t really touch anything on the circuit board besides the screw terminals, and obviously, the keypad.”
I think something is being missed when talking about “grounding”. Grounding is supposed to be an alternate pathway for electricity to discharge into the earth instead of traveling through a person. If you are “grounded” your body then becomes that alternate route. That is why electrical workers use fiber glass ladders and heavy leather gloves. They want to be a high resistance path to earth so that electricity can’t pass them, unlike a metal ladder, and also them subsequently.
The wrist band “grounders” are to be used when working around CMOS chips that are subject to being easily damaged due to a static shock. The purpose of the wrist band is that it will allow static electricity to leak away into the grounding network to which you are attached that may build up on you if you are standing on a rubber mat with shoes that have soles that can create static electricity.
You never want to be “grounded” because you become part of the circuit.
You see at science halls people that have their hair standing out straight from a static electricity charge. They have basically become a human capacitor. However, nothing happens to them because the stored electricity can’t discharge out because they are insulated from letting a discharge to occur, as opposed to grounding. If they were grounded a high static charge couldn’t build up.
Just to add my $.02…
I’ve worked with these sorts of boards for many many years. Especially with the newer circuit boards you would always want to handle them (while unpowered) with a grounding wriststrap. They are relatively cheap, and can prevent the static buildup (particularly worse in the cold dry winter months) from damaging sensitive electronics. Nothing worse than turning some long-awaited piece of electronics into a fancy doorstop.
$15 is a pretty cheap investment to protect your collection.
I would never suggest using the ground wire from the AC wiring as a means to ground yourself. It would certainly work, but you would probably be in close proximity to the dangerous live wires.
Lastly, I would never suggest playing around with such equipment while the system was hot. Touching the wrong thing can damage your prized piece of equipment, or worse, yourself.
Above all, be safe.
some panels can have multiple ground inputs for static protection
I agree. Just to clarify though… I was under the impression (perhaps falsely so), that the idea of grounding oneself by touching the bare ground wire in the AC bundle coming in (sometimes referred to as romex) was being suggested. This I feel is extremely dangerous.
Agreed. I would not endorse doing this, because if your ground lead touches hot, touches neutral, or connects the two, you’re out of luck.
Just put your ground clip onto the can/chassis of the panel, because it should be grounded. Check to see if there’s a green/bare wire attached to the can.
I’ve never used a ground strap before on anything and everything has been fine, but it’s an extra layer of protection.
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“because if your ground lead touches hot, touches neutral,”
Your ground and neutral are tied in together. It is the “hot” that you have to worry about.
The ground is an alternate pathway to the neutral that shunts an electrical current into the earth to help you from getting shocked from a faulty piece of electrical equipment that has a ground prong on its’ plug.
Take a voltmeter and check the voltages of a 120 VAC feed between Hot-Neutral and Hot-Ground, they should be the same.
Power down and check the resistance between the Neutral-Ground and it should be < 0.5 Ohms.
To add more confusion, fire alarm panels for the most part use a “Floating” ground, which is why you can get a “Positive” and Negative" ground fault from a DC circuit.
A floating ground is also used in car stereos. That is why you can get AC sound output coming out of a car 12 VDC system.
Simply put, an “AC” sound wave is a result of voltage being higher or lesser positive from a CIRCUIT BOARD fixed(floating) ground point of about 6.0 VDC and not your car’s chassis which is 0.0 Volts by being connected to the car battery’s negative terminal.
Toronto, Ontario guy
Not going to beat this dead horse to death, but just to clarify. Imagine the point that the AC comes into the panel. The Hot, Neutral and ground are all in close proximity. You are probably taking a pretty big risk by attaching yourself either via wriststrap or direct connection to the bare ground lead with it being so close to the hot. My impression from previous comments was it was being suggested that in lieu of a grounding wrist strap, one could just grab the grounding wire.
I’m only dragging this out, because I’ve noticed that there are quite a bit of younger folks in this forum. The power available in these panels can make for a very bad day if you touch the wrong thing. Above all, be careful. If you are experimenting and don’t have a lot of experience, please consult someone who knows before you touch something questionable. On another safety note, a lot of the panels have components that store voltage (capacitors). Most are relatively harmless, but some of the larger ones can give you a pretty unpleasant shock even after the panel has been powered down.
Bottom line. Fire panels are fun to play with and very educational. Live systems can be extremely dangerous, so take proper precautions and error on the side of safety.
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