Carflex uses?

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JJWalecka

JJWalecka

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Location
New England
I have always refered to "Liquid tight" with no metal sheath as Car flex (not sure of spelling). It is easy to cut and the fitting are inexpensive.
I disagree with its installation for 480 volt branch circuits. Especially with the potential of physical damage. Though my former employer loved to use it.
An E.M.T is changed over to Car flex then penetrates the roof decking into the bottom plate of an AC unit. Total length 5'. The installation and penetration is 25' in the air with little to no chance of physical damage.
Where the Car flex penetrates the decking would some type of bushing be needed or would the plastic sheath be adequat?
Also, where penetrating into the plate at the bottom of the unit can conductors be installed free air or would a raceway be required to be installed to the disconnect inside the unit? Their are other conductors installed free air per factory installation.
Any thoughts would be appreciated.
Thank you Justin W.
 
Re: Carflex uses?

There's nothing wrong with "carflex" as long as it's installed in a code compliant manner.

I happen to hate the metallic sealtight and I will not use it under any circumstances. I have seen far too much of it rust and self-destruct. Carflex does not have that problem.
 
Re: Carflex uses?

I will give you my opinion but remember it is opinion only My opinion plus two dollars will buy you a cup of coffee at most 7-11's

First how are you making the transition from emt to liquad tight (carflex)? why not use flex they make a flex to emt transition.

Second once inside the unit there is normally a place for the connector (a knockout or hole for the 3/4 or1 inch connector) from that point to the place you need to make your connections can be free wired just like you can free wire inside a box for a switch or receptical.

Third how are you keeping the roof from leaking where you penetrated the roof with your conduit? if it is directly below the AHU and and where the duct work also penetrates the roof no additional protection for the conduit is required.
 
Re: Carflex uses?

MarinesSgt0411
The EMT would have a connector to a Rigid coupling then to Greenfield or Liquid tight conn.

At the company that I am currently employed we use Green Field not Liquid tight. Though at former employers Liquid tight was used.

Only a thought, The raceway would penetrate inside the unit so liquid tight would not be required. Though the conductors would be protected inside the unit. Could the cold weather damage the conductors if THHN were used? I am presuming the insulation for the factory installation would compensate for extremities being installed free air.
I thought that the THHN would be better protected in an raceway.

I figured that car flex would be less expensive than Greenfield and quicker to assemble.

Justin W
 
Re: Carflex uses?

Peter D LOL...Quote from my former employer "use the non UL listed Liquid tight its cheaper" I will not mention names to protect the innocent.

Justin W.
 
Re: Carflex uses?

I figured that car flex would be less expensive than Greenfield and quicker to assemble.
Click to expand...
EMT connector, rigid coupling, flex connector or liquad tight connector.
flex to EMT connector.

OK you cut your flex or liquadtight to length you assemble the emt,rigid,LT or flex connection you fight getting the LT connector onto the LT because the LT is cold you fight getting the LT connector on the other end so what 10 15 minutes?

You cut your flex to length put a connector on one end the flex to emt connector on the other tighten the connector onto the EMT what 5 minutes 10 maybe

less material less time

liquad tight is great but if you do not have to use it WHY would you want to?
 
Re: Carflex uses?

Yes, I wasn't aware of any non-UL listed LFMC.
Click to expand...
A lot of it is not listed. Around here if you go to the supply house, will will get the non-listed type unless you specify that you want listed LFMC.
Don
 
Re: Carflex uses?

We use it all the time. Our most common use is in the local telephone CO's for their rectifiers. We have to go between the -48VDC buss bars and don't want to...well ground the hot lead out. While the light show is impressive, I don't think they'd invite us back for more work. Below is a pic of one such installation. Since using it for this, I've found dozens of other uses for it. I think it's a great product.

DSC03652.JPG
 
Re: Carflex uses?

Justin,

I don't agree with the opinion that it is ok to free air the circuit conductors. What the factory does is their business,Our obligation is to the electrical j-box,which is totally enclosed. It will take less time to do it once and that includes the material.
 
Re: Carflex uses?

By Frank: I don't agree with the opinion that it is ok to free air the circuit conductors. What the factory does is their business,Our obligation is to the electrical j-box,which is totally enclosed. It will take less time to do it once and that includes the material.
Click to expand...
In industral installations open conductors are run mainly because it saves down time and when they have to be replaced or upgraded to a larger size, Cable trays allow this to be done very fast. And when you need another circuit, well you get the idea. :D
 
Re: Carflex uses?

I guess I'm just old-fashioned; having learned the trade around Chicago, before all this plastic stuff, the metal-lined "sealtite" just seems "right" to me.

My main complaint about any type of flex is that it is usually installed in a manner that guarantees that it gets hit, tripped over, and damaged. I've lost count of the broken (or disconnected) fittings I've seen.

So, I've been cautious about using the all-plastic stuff, using it for lighter duty, more protected locations. So far, I have no complaints.

I suppose that I will continue to rely on the metal-lined stuff; if for no other reason than that I can buy it a couple feet at a time.
 
Re: Carflex uses?

I have only a small comment to add here. In my experience, if you are connecting an outside ac compressor and plan to use carflex for the connection, check first to make sure there is no 1 year old black Labrador puppy sharing the yard with that ac compressor. :(
 
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