Fire alarm voltage drop program

[Npstewart]

Hi everyone. Im helping someone in my office do some voltage drop calculations using Notifier's "DRAG & VDROP" program. This is basically a program where you select a device, and drag it to a distance from the FACP. My problem is that these panels only have a 2.5A power supply maximum. As soon as I drag on about 9 strobes, the power supply gets over-whelmed. If we do additional NAC circuits, then we would end up with 9 of them. Does anyone have experience with this particular program, or any suggestions on how to get more devices per NAC circuit?

This is a CLASS A, Style Z. By the way.

Thanks!

 

[dhalleron]

What size wire are you using? What distance? How bright are the strobes? What brand are the strobes?

Normally I figure 14 AWG and estimate 7 or 8 75cd strobes per circuit on about 400 - 500 feet of wire. Depending on distance, wire size and strobe current this number can go up or down.

Unless you have 9 strobes at very high candela settings then I don?t believe the circuit is exceeding 2.5 amps. My bet is the voltage drop is hurting you due to wire size and/or distance.

You only really need to figure the longest distance on your class A circuit. Either the outgoing or incoming.

 

[Npstewart]

The program I am using is specifically designed for "Notifier" systems. My problem isn't the voltage drop, it is that the power supply is too small and it gets overwhelmed with only 9 devices. All you have to do with this program is select the device model number you want, and drag it onto the system.

I spoke with Notifier about this issue a little bit ago. Apparently the program they issued is only for very small systems. It does not have the ability to add additional power supplies etc. which is my problem.

Thanks

 

[jleise]

Use the NAC Outpouts on the panel to drive an FCPS-24S8 this will give you 8 amps of NAC Power. The unit will also follow selective silence so you can have strobes continue to flash with horns shut down over 1 pair of wires.

 

[dhalleron]

My problem isn't the voltage drop, it is that the power supply is too small and it gets overwhelmed with only 9 devices.

I still find it hard to believe that you overwhelm a 2.5 Amp power supply with only 9 horn/strobes. How much current does each one draw?

An example would be if you use System Sensor P2RH set at the highest setting of 185 candela then each one draws .265 amps. That would still be 2.385 amps total.