3M - FB-FOAM

[Ravenvalor]

Hello,

A restaurant customer has 3 - dozen runs of conduit entering the floor from a big 15' long electrical panel. It is a floor to 7' tall type that houses the main breaker, all of the feeder breakers, all of the electrical panels plus all of the relays for the HVAC, hood fans and lighting. Some of the conduits are pulling air to the outside. On the other side of the wall of this panel is a biscuit making station. Over the past 23 - years a couple of pounds of flour has managed to get sucked into the electrical panel and it has coated the interior of the electrical panel significantly. Is it okay for me to block the outward draft of air by putting 3M - FB-FOAM inside each conduit. I could use the putty but the foam is much cheaper, quicker and seals better (at least temporarily, I know an inspector who does not allow the use of the foam for any electrical application. He thinks it is flammable and it is not UL listed for North Carolina).

Thanks for your help.

 

[guitarman21632]

According to the spec sheet on the 3M FB foam it is not for use in commercial construction that is probably why the inspector will not allow it. The only other option I know of outside of putty would be fire caulk.

 

[John120/240]

Why not duct seal ? It would be listed for sealing conduits.

 

[PetrosA]

PolyWater makes a foam sealant specifically for sealing electrical conduits. I can't imagine your inspector is going to have enough of an argument to fight that

http://www.polywater.com/FSTspec.pdf

 

[ActionDave]

Why not duct seal ? It would be listed for sealing conduits.

And would do a better job.

 

[Ravenvalor]

According to the spec sheet on the 3M FB foam it is not for use in commercial construction that is probably why the inspector will not allow it. The only other option I know of outside of putty would be fire caulk.

This particular inspector won't allow its use in residential either. Thanks for the help.

 

[Ravenvalor]

Why not duct seal ? It would be listed for sealing conduits.

Thanks John. The two issues with duct seal are 1) the foam can get to the conduit that is covered up with 23 year old conductors that I do not want to disturb. and 2) the foam would be less expensive.

 

[elecman250]

easy problem

easy problem

This is an easy problem to solve as I handle some very tricky sitations at my power facility. The product we normally use for sealing applications is a foam impregnated filler. Since its air, i dont think its going to be problem.

I would use DUCTOLOX 431 made by Arjunox (cant remember where they are located) to completely seal this off. Ducteez by Ramtec Corp ramteccorp.com is another non foam option that is UL listed. Although there have been times I have just a foam and ducteez in conjunction. We used to use oakum many years ago with Ducteez which created an incredible water blocking conduit running 4 - 500 cables.