help with adding device to FA system.

[electrofelon]

I never learned any FA stuff, its kinda a separate trade where I learned. I know some basics, but thats it. I have a job that I just need to add in one strobe and one smoke, just looking for some guidance. The device/system programming will be taken care of by others, but I need to run and tie in the wiring to the existing loop. I dont know if it is class A or not, and Im not sure if that matters. This is in upstate NY, its pretty unregulated but I dont know what code or standard if any applies. Attached is a picture of the strobe, its simplex. So here are my questions:

1) So basically when I add a device, can I tee/splice off an existing loop with a branch, or do I need to rearrange it so the loop goes both in and out of the new device?
2) Can someone point to a basic smoke detector for this system? I got the new strobe by looking at what was there, but I forgot to look at a smoke and the job is kinda far away.
3) The NAC conductors are red and black as expected, but the smokes are a cable assembly consisting of two ~18 guage wires. I am used to seeing blue and white. Is that abnormal?

Thanks.

 

[gadfly56]

I never learned any FA stuff, its kinda a separate trade where I learned. I know some basics, but thats it. I have a job that I just need to add in one strobe and one smoke, just looking for some guidance. The device/system programming will be taken care of by others, but I need to run and tie in the wiring to the existing loop. I dont know if it is class A or not, and Im not sure if that matters. This is in upstate NY, its pretty unregulated but I dont know what code or standard if any applies. Attached is a picture of the strobe, its simplex. So here are my questions:

1) So basically when I add a device, can I tee/splice off an existing loop with a branch, or do I need to rearrange it so the loop goes both in and out of the new device?
2) Can someone point to a basic smoke detector for this system? I got the new strobe by looking at what was there, but I forgot to look at a smoke and the job is kinda far away.
3) The NAC conductors are red and black as expected, but the smokes are a cable assembly consisting of two ~18 guage wires. I am used to seeing blue and white. Is that abnormal?

Thanks.

1) You must add the device in series. You can do it via feed and return with a 4-conductor cable.
2) This is kinda tough, as you don't indicate if it is addressable or conventional. Here is something for conventional, and here is something for addressable.
3) Do you mean "wires" as in 2 conductors or "cables", as in a total of 4 conductors?

 

[electrofelon]

1) You must add the device in series. You can do it via feed and return with a 4-conductor cable.
2) This is kinda tough, as you don't indicate if it is addressable or conventional. Here is something for conventional, and here is something for addressable.
3) Do you mean "wires" as in 2 conductors or "cables", as in a total of 4 conductors?

1) Ok, its a single 3/4 pipe I brought from an existing 4 sq box to the new devices so I will go in and then back out.
2) Oh of course, looking at the strobe wont tell you if its addressable, duh..
3) Its a cable consisting of two conductors, that they interconnected the SD/HD with.

Edit: thanks for the help!

 

[gadfly56]

1) Ok, its a single 3/4 pipe I brought from an existing 4 sq box to the new devices so I will go in and then back out.
2) Oh of course, looking at the strobe wont tell you if its addressable, duh..
3) Its a cable consisting of two conductors, that they interconnected the SD/HD with.

Edit: thanks for the help!

Prototypical "fire wire", 2-conductor



Prototypical "fire wire", 4-conductor

 

[electrofelon]

Prototypical "fire wire", 2-conductor

View attachment 20387

Prototypical "fire wire", 4-conductor

View attachment 20388

Yup thats it. Most of my FA experience is actually in RI which I know is pretty strict.
There I always see THHN.

So Ill probably have to go back to find out if its addressable so I can get the appropriate detector.

 

[gadfly56]

Yup thats it. Most of my FA experience is actually in RI which I know is pretty strict.
There I always see THHN.

So Ill probably have to go back to find out if its addressable so I can get the appropriate detector.

Ahhh, yes, RI, which has more ridiculous laws than NJ, which I'd never have believed prior to coming to this forum.

 

[Fire Pro]

help with adding device to FA system.

You can t-tap off an slc circuit, smokes, pull stations, etc. Not a nac circuit.

If I read correctly, you're trying to find a compatible detector? What kind of control panel is it?

 

[electrofelon]

You can t-tap off an slc circuit, smokes, pull stations, etc. Not a nac circuit.

Why is that? almost seems like it would be the other way around.

If I read correctly, you're trying to find a compatible detector? What kind of control panel is it?

Yes but I will have to go back to get more info. I dont have any equipment info other than the picture of the strobe in the OP. I should be going back there tomorrow.

 

[electrofelon]

Next question. What is the procedure for disconnecting or interrupting a NAC or SLC loop? Will this set off the system or just give some sort of fault message at the control panel? What about taking the SD off its base?

 

[gadfly56]

Why is that? almost seems like it would be the other way around.



Yes but I will have to go back to get more info. I dont have any equipment info other than the picture of the strobe in the OP. I should be going back there tomorrow.

Assuming that the SLC loop is configured Class B, you can t-tap from a device to a nearby location because each device has a unique address and if it drops off the loop the panel knows right away, regardless of circuit configuration. You can't do this with the IDC of a conventional panel.

The vast majority of notification appliances, even for addressable panels, are dumb. Supervision is provided by an end-of-line resistor (EOLR). If you t-tap the circuit and lose that branch, the panel will never know that those devices are missing because they don't run through the EOLR.

 

[gadfly56]

Next question. What is the procedure for disconnecting or interrupting a NAC or SLC loop? Will this set off the system or just give some sort of fault message at the control panel? What about taking the SD off its base?

Check in with your point-of-contact (POC) and let him/her know you will be working on the fire alarm system so they can make the appropriate announcements to the occupants. If required, contact the fire department or AHJ and tell them you will be taking the panel off line. Contact, or have your POC contact, the central station (if there is one) and have the panel put on test.

If you short the NAC loop or open it you'll get a trouble message on the panel. If you remove a smoke detector you'll get a trouble message at the panel. If you short the SLC loop, you'll get a trouble message on the panel AND you'll bring down every device on the loop. If you don't have an addressable panel and short the indicating device circuit (IDC), which is the equivalent of the SLC, you'll get an alarm. Back in the day, if I was lifting a loop I'd do it one wire at a time and tape the end or put a wire nut on it to prevent shorts.

Once your are done, make sure the panel is clean and reverse the steps in paragraph one.

 

[Strathead]

You probably aren't going to like this answer. Right off the top, the picture you included shows Simplex. Simplex is a proprietary system for which you will have to get parts from them if they need to be new and have a factory warranty. Second you give no indication of the year the system comes from. Way back all systems were what we refer to as conventional. Then around the 90's systems became "addressable' this referred only to the signalling devices like smoke detectors, just recently Simplex has been pushing addressable notification devices, (horns and strobes).

The short answer for you is that you just need to bite the bullet, call Simplex. You can do parts and smarts install where they just provide the device and programming, but they will also walk you through the installation.

Regarding other questions:
The reason smoke detectors don't generally require tandem wiring is because they each have a unique digital address so the panel "knows" when one gets disconnected. NAC circuits require wiring such that they are hooked up lie a ladder with a resistor at the end. If a wire comes loose or shorts the resistance changes and the panel detects it. If a "branch" was sent off, then those wires could come loose and have no effect on the resistor, hence not legal.

In the old days, smoke detectors were hooked up similarly. This is still an acceptable system, just not often economical so usually not done any more.

 

[Strathead]

Check in with your point-of-contact (POC) and let him/her know you will be working on the fire alarm system so they can make the appropriate announcements to the occupants. If required, contact the fire department or AHJ and tell them you will be taking the panel off line. Contact, or have your POC contact, the central station (if there is one) and have the panel put on test.

If you short the NAC loop or open it you'll get a trouble message on the panel. If you remove a smoke detector you'll get a trouble message at the panel. If you short the SLC loop, you'll get a trouble message on the panel AND you'll bring down every device on the loop. If you don't have an addressable panel and short the indicating device circuit (IDC), which is the equivalent of the SLC, you'll get an alarm. Back in the day, if I was lifting a loop I'd do it one wire at a time and tape the end or put a wire nut on it to prevent shorts.

Once your are done, make sure the panel is clean and reverse the steps in paragraph one.

Sort of good advice, but not if one isn't comfortable with fire alarm. For example, in a high rise in Oakland which had a Simplex system in the 1990's there was a ground fault that couldn't be found. Because of that, a short of the positive wire on a NAC circuit would send the entire 12 floors in to alarm. That is the moment that electrofan will wish he had just called Simplex first.

 

[gadfly56]

Sort of good advice, but not if one isn't comfortable with fire alarm. For example, in a high rise in Oakland which had a Simplex system in the 1990's there was a ground fault that couldn't be found. Because of that, a short of the positive wire on a NAC circuit would send the entire 12 floors in to alarm. That is the moment that electrofan will wish he had just called Simplex first.

First, I am under the impression that this is a small system and only the NAC is under discussion for modification.

Second, I do not see how shorting the NAC can cause them to actually ring. For one thing, you have to reverse polarity to get the horns to rock and roll, for another you shouldn't have more than one floor on a NAC.

 

[Strathead]

First, I am under the impression that this is a small system and only the NAC is under discussion for modification.

Second, I do not see how shorting the NAC can cause them to actually ring. For one thing, you have to reverse polarity to get the horns to rock and roll, for another you shouldn't have more than one floor on a NAC.

it isn't surprising that you don't "see" how ground faulting (not shorting) the NAC can cause an alarm. The best we could figure, the positive ground fault caused a voltage in the conventional initiating circuit (this was pre SLC) that led the panel to believe an initiating circuit had gone in to alarm. For further reference, the ground fault actually ended up being in the fireman's communication jacks int he elevator, but was intermittent. I personally remover resoldered and replaced all 12 floor's jacks. I very good solderer. I am nuclear submarine trained in soldering. The problem finally went away.

Also, I believe the OP was asking about a NAC and a smoke detector.

 

[electrofelon]

Thanks guys for the crash course in FA. To clarify I am adding one strobe and one SD. Nothing is real high stakes here, its in a boiler room that is off line now, not like an apartment building or anything.

Ill be going to tomorrow and Ill call simplex too.

 

[gadfly56]

Thanks guys for the crash course in FA. To clarify I am adding one strobe and one SD. Nothing is real high stakes here, its in a boiler room that is off line now, not like an apartment building or anything.

Ill be going to tomorrow and Ill call simplex too.

Not to add to your woes, but if the device is going in a boiler room you may want to confirm that the ambient temperature doesn't exceed 100°F. This is the operating temperature limit for smoke detectors, whether conventional or addressable based on the UL listing, although Simplex says that the operating limit can be up to 122°F. If the heat detector is addressable it has the same limits. See the cut sheets I linked to up-thread. In addition, it is typical to place heat detectors in a boiler room in case you have any smoke as a result of startup or maintenance procedures.

 

[JohnCA]

Thanks guys for the crash course in FA. To clarify I am adding one strobe and one SD. Nothing is real high stakes here, its in a boiler room that is off line now, not like an apartment building or anything.

Ill be going to tomorrow and Ill call simplex too.

I always design the boiler room with a Heat Detector instead of a Smoke Detector. It really help if we know the model of the FACP

John.
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