Do you have to use expansion fittings in E.M.T installat

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JJWalecka

JJWalecka

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New England
If the structure has expansion joints. Do you have to install expansion fittings in E.M.T. if it is mounted to the structural decking (Pearling)? I was told that if the E.M.T run is ended within ninety feet you do not need an expansion fitting. Is this correct? Where in the code does it state this? Thank you for your time and effort.

Justin
 
Re: Do you have to use expansion fittings in E.M.T installat

Yes you have to instal something to address the building movement.

The NEC section escapes me. 300.7(B) somewhat addresses it, but it is for raceways exposed to different temperatures.

Get the expected movement distance and direction of movement from the structural engineer.
Most people use flex or sealtite at the joint rather than an expensive fitting.
 
Re: Do you have to use expansion fittings in E.M.T installat

Try 352.44 of the 02 and 05 also subsequent tables
Although thats for RNC not EMT. For expansion fittings for EMT and building transitions I would consult with the manufactures. The recommendation to install flex is generally applied also.

Charlie

[ February 18, 2005, 07:05 PM: Message edited by: cpal ]
 
Re: Do you have to use expansion fittings in E.M.T installat

We used to do alot of work in a local building that had expansion joints in it. We would put in a couple of flex-EMT fittings and about a foot of flex. Then some bonding clamps and a ground wire to make the ground continuous through the raceway. That was the requirement from the building owner, which was Honeywell.
 
Re: Do you have to use expansion fittings in E.M.T installat

2002 code 300.7(B) FPN says to multiply the expansion length of the PVC in Table 352.44(A) by 0.20 or 20%. If the result is more than 6mm or .25 of an inch than it needs an expansion fitting.
 
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