atcomsystems.ca/forum Forums Wiring - Telecom Carriers - Trunks & Services Cabling Telephones Systems Wiring running cable in plenum ceiling

Technically those openings are part of the AC system. Since the premise behind an air plenum ceiling is that the return air is not ducted, the entire ceiling is an air return plenum and those openings are usually sized and designed for a specific air flow on the return side of the AC system. Since it has already been inspected and low voltage is not inspected in your area you may "get away with it" but I have seen instances where sometime later on down the road a renovation is done or some catastrophy occurs and the inspector finds out who installed that cable and they get nailed in terms of fines etc. If you want to risk it that is up to you but go into it with your eyes open. Those Arlington bushings are pennies and a quick word to the electrician will probably get you a scrap or two of conduit, compare that to a hefty fine later on down the road when you are not expecting it and I would choose the conduit and bushings in a second. Besides, all you have is your reputation don't ruin it over a couple of bucks worth of materials.

the Arlington ones say they are now rated for air handling spaces

https://www.aifittings.com/whnew26.htm

Just weighing in

I agree with Chuck and Ed punch holes and metal sleeve it

You shouldn't use those openings. Use 3/4" conduit with "bang-on" bushings.

One good lesson to learn on any new construction job is to get the HVAC prints or ask a bunch of questions form the various other trades. This alone can save you lots of aggravation when they the decide to place the HVAC unit on the roof and your wires are running under where the hole will be cut in the roof, Good rule of thumb is to just stay away from all other mechanical trades in the ceilings.

Takes very little time and money to install sleeves and when you are finished there is no question the job was done right.

It will take less time to install the sleeve than has been spent discussing the issue on this forum.


Bill

And that's the truth! :thumb:

I don't think that I have ever seen a plenum-rated bushing other than metal ones.

The old black or brown bakelite ones. And if Arlington says on the box that their's are listed for air handling spaces you can use them.

Now, as far as these cutouts. Anything else running through them like electrical or plumbing? What did the sparkies do to get from one side to the other?

It's fair to say that if everything else is run through them you can too but if you see separate penetrations follow the lead.

If this is not a fire rated partition (and it wouldn't be with cutouts in it) you don't have to use sleeves.

-Hal

sparky has flex popped through and mudded in , hvac used a hammer on each side to get his thermostat wire through


nobody else is using the cutouts , I don't see my cable bundle affecting it , but Ill find another path