# Fire Alarm Question.



## Victory Pete (Jun 29, 2012)

I am adding some horn/strobes to an existing class B system. the local vendor supplied Cooper Wheelock Exceder units. The existing units have the 2 blues and 2 white wires on a common screw, the new ones show the whites on a common screw, but the blues has 2 screws, one for input and one for output. I have no way of determining input and output on the existing wires.


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## halfamp (Jul 16, 2012)

with a meter..

one leg will have power from facp, other leg should have your end of line resistor


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## Victory Pete (Jun 29, 2012)

halfamp said:


> with a meter..
> 
> one leg will have power from facp, other leg should have your end of line resistor


 Our system does not have an end of line resistor, it ends back in the panel.


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## MTW (Aug 28, 2013)

I've put in a gazillion of there. Input and output doesn't matter. Just make sure you observe polarity, and you will be fine.


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## Victory Pete (Jun 29, 2012)

MTW said:


> I've put in a gazillion of there. Input and output doesn't matter. Just make sure you observe polarity, and you will be fine.


 Okay thanks, but where do I put the blue wires, there are 2 places for them to go, in and out. the whites are common. There are 3 terminals in all, blue in, blue out and common white.


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## Southeast Power (Jan 18, 2009)

The guy that sold them will most likely say that inside, both of the blues are connected.
I wanted to say it like that so it didn't sound like an echo in here.


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## MTW (Aug 28, 2013)

Victory Pete said:


> Okay thanks, but where do I put the blue wires, there are 2 places for them to go, in and out. the whites are common. There are 3 terminals in all, blue in, blue out and common white.



Put one blue wire on each terminal. Done.


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## MTW (Aug 28, 2013)

Note: if anyone is reading this and going :blink: because of the blue and white wires on a NAC circuit, that's because the RI fire alarm code mandates those colors to be used.


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## Victory Pete (Jun 29, 2012)

What is the input and output for actually? I understand in my situation it may not matter, but I am curious.


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## halfamp (Jul 16, 2012)

if it returns to the panel it's not a class B system. just sayin


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## Victory Pete (Jun 29, 2012)

halfamp said:


> if it returns to the panel it's not a class B system. just sayin


My inspector said it was, he has been on this job many times.


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## halfamp (Jul 16, 2012)

this applies to notification circuits as well


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## don_resqcapt19 (Jul 18, 2010)

halfamp said:


> if it returns to the panel it's not a class B system. just sayin


It can be. If the wires that return to the panel only connect to an end of line resistor, it is still a class B system. I have done installations where the project specs required that.


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## halfamp (Jul 16, 2012)

don_resqcapt19 said:


> It can be. If the wires that return to the panel only connect to an end of line resistor, it is still a class B system. I have done installations where the project specs required that.


Correct. Except..



Victory Pete said:


> Our system does not have an end of line resistor, it ends back in the panel.


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## LARMGUY (Aug 22, 2010)

don_resqcapt19 said:


> It can be. If the wires that return to the panel *only *connect to an end of line resistor, it is still a class B system. I have done installations where the project specs required that.


You just contradicted yourself. Look at the diagram above you and read your post.


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## Victory Pete (Jun 29, 2012)

halfamp said:


> Correct. Except..


I measured to see what was on 2 sets of wires at a detector. 22 volts on a pair and 16 volts on the other pair, no end of the line resistor there I believe.


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## LARMGUY (Aug 22, 2010)

Victory Pete said:


> Okay thanks, but where do I put the blue wires, there are 2 places for them to go, in and out. the whites are common. There are 3 terminals in all, blue in, blue out and common white.


The two terminals that are left over are bussed and are mechanically and electrically the same.


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## Victory Pete (Jun 29, 2012)

LARMGUY said:


> The two terminals that are left over are bussed and are mechanically and electrically the same.


Okay, so why do they specify in and out?


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## MTW (Aug 28, 2013)

don_resqcapt19 said:


> It can be. If the wires that return to the panel only connect to an end of line resistor, it is still a class B system. I have done installations where the project specs required that.



The RI code requires that for all Class B systems (EOL resistors in panel terminated on a terminal block.)


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## B4T (Feb 10, 2009)

don_resqcapt19 said:


> It can be. If the wires that return to the panel only connect to an end of line resistor, it is still a class B system. I have done installations where the project specs required that.


It does make it easier to find the EOL.. I always mark the smoke detector or pull station where it is located... LOTS of guys don't..


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## LARMGUY (Aug 22, 2010)

Victory Pete said:


> Okay, so why do they specify in and out?


 
http://www.cooperindustries.com/content/dam/public/safety/notification/Resources/Instruction%20Sheets/P85066.PDF

There are several possible reasons. They supervise horn strobes by reversal of polarity. They have a syncing signal for the horns for temporal three audio patterns and they help in troubleshooting and locating up and down line devices. Resistors are in parallel so the value is halved. Are you saying the resistor is inside the FACP or the NAC?


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## Victory Pete (Jun 29, 2012)

LARMGUY said:


> http://www.cooperindustries.com/content/dam/public/safety/notification/Resources/Instruction%20Sheets/P85066.PDF
> 
> There are several possible reasons. They supervise horn strobes by reversal of polarity. They have a syncing signal for the horns for temporal three audio patterns and they help in troubleshooting and locating up and down line devices. Resistors are in parallel so the value is halved. Are you saying the resistor is inside the FACP or the NAC?


The inspector pointed to it in the FACP.


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## Southeast Power (Jan 18, 2009)

Victory Pete said:


> The inspector pointed to it in the FACP.


I have seen where the EOL was brought back for troubleshooting and testing and people called it a class A system.


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## NacBooster29 (Oct 25, 2010)

Is this a new system? I can't think of any place in r.I. that will accept a class"b" loop . 
That being said to extend your nac circuit legally (in r.I.) you cannot simply bring your feed and return anywhere into an existing loop. And splice in the box. I'm not saying it won't work, but per letter of their code can't make splices in anything but a hinged covered lockable, fire alarm term cabinet. 
Also it sounds like you may be a newbie to fire alarms, maybe get some hands on help so you don't impair a life safety system.


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## Victory Pete (Jun 29, 2012)

NacBooster29 said:


> Is this a new system? I can't think of any place in r.I. that will accept a class"b" loop .
> That being said to extend your nac circuit legally (in r.I.) you cannot simply bring your feed and return anywhere into an existing loop. And splice in the box. I'm not saying it won't work, but per letter of their code can't make splices in anything but a hinged covered lockable, fire alarm term cabinet.
> Also it sounds like you may be a newbie to fire alarms, maybe get some hands on help so you don't impair a life safety system.


 
This system is now all set and inspected, I am not a "newbie", I just assume nothing, and this was an old installation.


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