ECN Electrical Forum - Discussion Forums for Electricians, Inspectors and Related Professionals
ECN Shout Chat
Shout Box
Recent Posts
sec cable code conflict
by gfretwell. 11/18/18 12:25 PM
This anti-theist is priceless!!!
by Texas_Ranger. 11/17/18 02:15 PM
High current GFI vs regular GFCI
by Texas_Ranger. 11/17/18 02:07 PM
Single phase and what you call it.
by dsk. 11/12/18 11:10 AM
New in the Gallery:
What is this for?
Plug terminals
Who's Online Now
0 registered members (), 29 guests, and 23 spiders.
Key: Admin, Global Mod, Mod
Previous Thread
Next Thread
Print Thread
Rate Thread
Expansion Fittings #170818
11/12/07 06:13 PM
11/12/07 06:13 PM
Admin  Offline
OP
Administrator
Member
Joined: Oct 2000
Posts: 3,524
NY, USA
Quote
This is what happens when the expansion fitting is NOT installed. The side of the box was pulled completely out. These were taken in a parking garage that is being renovated. The metal conduit will probably be replaced by rigid non-metallic conduit sched. 80 WITH expansion fittings.

[Linked Image]

Quote
This is the second of two pictures showing an expansion fitting on rigid conduit. This is how it should be done.

Alan Nadon

[Linked Image]

2017 / 2014 NEC & Related Books and Study Guides
Re: Expansion Fittings [Re: Admin] #170907
11/14/07 06:45 PM
11/14/07 06:45 PM
B
BigJohn  Offline
Member
Joined: Mar 2004
Posts: 391
Boston, MA
I understand the reason for expansion fittings, but never really saw an install where I was thinking "They'd really be up a creek if they hadn't put that expansion coupling in." Now here's a dramatic example of what happens when you don't. Neat.

-John

Re: Expansion Fittings [Re: BigJohn] #170918
11/14/07 11:44 PM
11/14/07 11:44 PM
S
SP4RX  Offline
Member
Joined: Oct 2007
Posts: 56
Edmonton, Alberta, Canada...eh
Wow.

Is expansion/contraction really what caused that?? I never would have guessed that a lack of provision for expansion could result in something this dramatic.

Kinda makes me ponder the 250 feet or so of EMT I just ran the other day...oh wait, that was inside a heated building. *whew*


Shawn.

Re: Expansion Fittings [Re: SP4RX] #170956
11/15/07 07:42 PM
11/15/07 07:42 PM
J
jdevlin  Offline
Member
Joined: Aug 2002
Posts: 402
welland ontario canada
That must have been some long conduit run to expand/shrink what looks like 2 inches. Are you sure it is not from damage further down the conduit run?

Re: Expansion Fittings [Re: jdevlin] #170970
11/16/07 12:06 AM
11/16/07 12:06 AM
Lostazhell  Offline
Member
Joined: Feb 2004
Posts: 1,431
Bakersfield, CA (Originally Or...
There's a run of 3/4 galvanized that runs along a fenceline for about 1200 feet out where I work (For H2S monitors) In the cold, it's straight as an arrow, but once it gets above about 80F or so... It starts doing the wave... along the WHOLE run!

Re: Expansion Fittings [Re: Lostazhell] #171132
11/20/07 12:43 PM
11/20/07 12:43 PM
S
SteveFehr  Offline
Member
Joined: Mar 2005
Posts: 1,213
Chesapeake, VA
The coefficient of thermal expansion for steel is 0.00000645in/in/deg. Doesn't sound like much, but for a 100' piece of pipe, the difference between a -20F day and a 110F day is 1". Aluminum expands twice as much as steel. Concrete is practically identical to steel. (Convenient for rebar, eh?) BUT, if that concrete has expansion joints, and the steel doesn't...

PVC is far worse, as it has a much higher coefficient of expansion. A similar piece of RNC would have an appx 4.5" expansion/contraction.

Last edited by SteveFehr; 11/20/07 12:45 PM.
Re: Expansion Fittings [Re: SteveFehr] #182701
12/07/08 12:39 AM
12/07/08 12:39 AM
JoeKP  Offline
Member
Joined: Mar 2008
Posts: 144
Berkley, MA
look @ how bent up it is, i don't think an expansion fitting would of helped that


-Joe
“then we'll glue em' then screw em'”
-Tom Silva
TOH

Featured:

2017 Master Electrician Exam Preparation Combos
2017 NEC Electrician
Exam Prep Combos:
Master / Journeyman

 

Member Spotlight
Posts: 165
Joined: March 2007
Show All Member Profiles 
Top Posters(30 Days)
Admin 7
Popular Topics(Views)
251,586 Are you busy
188,736 Re: Forum
178,445 Need opinion
Powered by UBB.threads™ PHP Forum Software 7.6.1
(Release build 20180101)
Page Time: 0.018s Queries: 15 (0.003s) Memory: 0.9870 MB (Peak: 1.1436 MB) Zlib enabled. Server Time: 2018-11-19 03:02:20 UTC