# High voltage junctions inside the FACP



## firemanx (Jan 29, 2016)

I've come across a situation that I'm looking for some guidance and code snippets for.  In a fire alarm control panel, there is a transformer that steps down the structure electricity down from 120v to 24v.  The 120v structural wiring connects to the transformer with wire nuts inside of the FACP.  It has been my understanding that there were to be no high voltage splices allowed inside of the FACP, however I am unable to locate a code snippet discussing this.  It appears that the manufacturer of the FACP doesn't take a stance on the connection, however they direct the installer to use a terminal block inside of the FACP to make the high voltage connection to the transformer when the AHJ doesn't allow wire nuts.

I've been through NFPA 72 and 70 some and am having some trouble in direction.  Any help or pointing me the right way would be very much appreciated.  Thank you in advance.


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## cda (Jan 29, 2016)

Wonder why the terminal block was not used?

If manufacture says it can be done either way, I would go with that.

I guess is there much difference between a wire nut connection and a terminal connection?

Yes I would prefer the terminal, and I think you could require it also


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## firemanx (Jan 29, 2016)

> Wonder why the terminal block was not used?If manufacture says it can be done either way, I would go with that.
> 
> I guess is there much difference between a wire nut connection and a terminal connection?
> 
> Yes I would prefer the terminal, and I think you could require it also


I agree, a splice is a splice.  Although I can't find a code reference, the impression that I was given was that NFPA 70 prevents splices to be made inside of the FACP as it is not approved for that purpose.  Again, I can't find code to support that and my intent isn't to find code to interpret so that splices must be made outside of the FACP.  I'm simply trying to find out the truth of the matter, if high voltage splices are or not allowed in the FACP based upon any existing code in 70 or 72.


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## cda (Jan 29, 2016)

Where are the electricians / electrical inspectors on this site???

It kind of is in a junction box!!


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## mtlogcabin (Jan 29, 2016)

The connection should be located behind the galvanized plate with the yellow high voltage sticker. If there is not a separate compartment then the connect must occur at a terminal block.The high voltage must terminate at this point. It cannot pass through and power another device.

View attachment 2178


View attachment 2178


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## firemanx (Jan 29, 2016)

Thanks for this.  Is the terminal block requirement found in 70?


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## north star (Jan 29, 2016)

*@ ~ @*

firemanx,

As I understand Power Limited Fire Alarm circuit wiring,

( PLFA ) in the NEC, all connections must be made in a

listed box or enclosure [ *RE:* Article 300.15  ]........Since

your FACP has an integral enclosure built in to it, that

it where your connections should occur, ...from normal

premise wiring 120V down to the 24v........The connections

can be either through the use of wire nuts or through a

terminal block.........You have stated this yourself in your

OP.



> * " ...however they direct the installer to use a terminal block inside of the**FACP to make the high voltage connection to the transformer when the AHJ*
> 
> *doesn't allow wire nuts.  "*


According to the NEC, it is up to you to find out if theAHJ allows wire nuts inside the FACP,  [* RE:* Article 110.2

& 110.3  ].

FWIW, ...IMO, a listed & approved type of terminal block is a

much better choice .

Hope this helps !

*@ ~ @*


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