View Full Version : Code Question: MC cable touching copper water pipe in ceiling. Problem?
PabNYC
10-30-2008, 01:50 PM
It is an easy fix either way but a contractor was at my house the other day and mentioned that in the ceiling the MC cable was touching the copper water lines and it was a problem.
Is this:
A: A problem (code violation?) and why?
B: Not a problem
Thanks!
jar546
10-30-2008, 06:32 PM
Any metal touching copper will eventually be a problem due to corrosion and oxidation. Don't let it touch it.
Our inspectors do not want ANY electical wire touching a plumbing water line. And are not too crazy about drain lines.
PabNYC
10-31-2008, 08:12 AM
In most areas I can just secure the electrical cable tighter to the ceiling with clamps but in tighter areas would it be sufficient to use the foam pipe insulation to prevent contact between the two?
Thanks!
jwelectric
10-31-2008, 10:37 AM
Code Question: MC cable touching copper water pipe in ceiling. Problem?
This is not a code problem
jar546
10-31-2008, 01:35 PM
This is not a code problem
Not necessarily, it depends on what the MC is touching or exposed to.
NEC 330.12(4)
jwelectric
10-31-2008, 02:48 PM
Not necessarily, it depends on what the MC is touching or exposed to.
NEC 330.12(4)
330.12 Uses Not Permitted.
(4) Where subject to cinder fills, strong chlorides, caustic alkalis, or vapors of chlorine or of hydrochloric acids
It is an easy fix either way but a contractor was at my house the other day and mentioned that in the ceiling the MC cable was touching the copper water lines and it was a problem. Thanks!
Damn, I thouhgt you were for real for a second but then I came back to reality.
What the original poster asked is in no way a problem except is the mind of some untrained, uneducated guessers.
sparkie
10-31-2008, 07:57 PM
There is no code violaton here. Personally, I would prefer for MC not to touch the copper water pipe. Often this is where corrosion is seen. Perhaps due to different types of metal.
kingsotall
10-31-2008, 08:23 PM
Our inspectors do not want ANY electical wire touching a plumbing water line. And are not too crazy about drain lines.
Seems the sparky's up here think our pipes are for supporting their wires. Gets really annoying once the home theater guys have followed suite along with the central air pipes basket weaving through all the PEX, too. :mad:
What's really annoying is when you predrill your holes and the electricians think that is a convenient place to run their wires through. Or, that the center of a 4" wall is the best place for their Romex or conduit, especially if they can see a plumbing pipe coming out of the floor right beneath it.
Redwood
11-01-2008, 08:09 AM
I like when they mount their panel above the stubs in the slab for the water and sewer lines...
Thats rocket science!
Speedy Petey
11-01-2008, 08:55 AM
Oh give me a break you guys. Plumber are FAR worse with the "I am the only one on the job" mentality.
BTW HJ, YES, the center of a 4" stud IS the ONLY place to run the wire.
A) ANY electrician who uses a plumbing pipe to support his wires is a hack.
B) ANY electrician who uses someone else's drill holes in framing is a jerk.
3) ANY electrician who puts a panel right above pipes stubbed out of a slab is either a dumbass or was told to do so by the builder.
What about the plumber who runs a vent stack from a bath vanity sink right straight up from the sink, knowing full well that there will be a vanity light dead center over the sink?
It goes both ways guys, and out stuff is WAY more flexible that yours, remember that. You can push a wire out of your way, I cannot mount a pancake box right to your vent stack!
kingsotall
11-01-2008, 06:05 PM
Oh give me a break you guys. Plumber are FAR worse with the "I am the only one on the job" mentality.
Left out, "that matters." :)
TheElectricalGuru
11-02-2008, 10:13 AM
lol....man I get a chuckle when I read some of these posts...lol.....
NO it is not a violation of the NEC, and what I think someone was trying to make reference too was 110.14 in regards to dissimilar metals....BUT since we are not talking about terminations.....who cares....110.14 would not apply ANYWHERE in that question....
so.....yet again as far as the NEC is concerned...no violation of the MC touching the metal waterpipe.....and hopefully if they DO have metal water pipes they have done their work to meet 250.104(A)(1) anyway....no worries.
frenchie
11-02-2008, 01:37 PM
From a carpenter's view... electricians and plumbers BOTH suck, and NEITHER ought to be allowed near a sawzall!
:D
But seriously... there's nothing on this in the electical codes, but isn't there something in the plumbing code? I know they have to use copper hangers on copper pipes, and you're supposed to use copper nails in those hangers... same logic, no? Dissimilar metals = corrosion?
Might want to cross-post this in plumbing.
jwelectric
11-02-2008, 03:18 PM
Frenchie where you been?
jar546
11-02-2008, 07:46 PM
Although in this case it is not a code violation, it should be addressed so it does not cause a problem in the future.
Remember, codes are minimum standards, minimum. The electrician was right to point this out.
TheElectricalGuru
11-08-2008, 09:56 AM
Jar,
May I ask what problem it will cause if it did touch? Considering the galvonic reaction usually takes a catalyst to happen I guess I would be interested in knowing what you think would happen in a closed ceiling and a MC touching the pipe?
Not being a SmartA$$...just wanted your view on it.
jar546
11-08-2008, 02:40 PM
My view is that I have inspected thousands of homes from brand new to ove 200 years old and found that in many cases whenever the two metals touch there is a problem. Whether pinhole leaks that start by simply rubbing the copper with your fingernail to the already fragile soldered copper connection deteriorating then being accelerated with the addition of a disimilar metal.
What may be approved by code or still works a couple of years later may be a problem in a few more years.
I once found a pinhole leak cause by a twist tie from a garbage bag that for whatever reason was placed on a section of copper pipe.
Depending on where you are from, the quality of the water that runs through your pipes and whether or not it is from a well or public water may cause your mileage to vary.
One of the best ones was a very expensive fix after the EGC clamp on a water main deteriorated the pipe until it burst when no one was home. It was a finished basement.
Many of you may be very familiar with new installs but I am looking at piping systems that are at or near the 100 year mark. Many of the leaks that I find are from homes that are not that old, especially when they have well water and a very low pH and a high iron content which is more than common in my area.
So no code says you cant do it but is it so hard to move it out of the way or do we need to make an issue from a 10 second fix opinion?
xroad
11-08-2008, 10:11 PM
Eh ... Sorry to interrupt ..... What is MC? New at this stuff, still learning.
jar546
11-09-2008, 05:40 AM
Eh ... Sorry to interrupt ..... What is MC? New at this stuff, still learning.
Looks like BX if that helps you. See Article 330
http://ace.imageg.net/graphics/product_images/pACEBW-981011reg.jpg
TheElectricalGuru
11-09-2008, 05:47 AM
Interesting considering I have also inspected nearly 5,000+ homes as a Home Inspector and countless numbers as a municipal inspector and have never run into the problem. You simply can't fix stupid and the things people do which I see on a daily basis. However, I am not concerned about a piece of MC Cable touching a water pipe.....but alas thats only my opinion and if it is as simple as the electrician moving it out of the way in order to make them feel better....go for it.
Now....if the issue is BX and someone THINKS it's MC then we could have a problem in older homes because MC is not BX and the issues of improper use of the outer jacket of BX is wide spread and is a different issue...The original OP was in my opinion refering to new MC in a new installation.........BX is very different than MC of today.
frenchie
11-09-2008, 11:42 AM
Eh ... Sorry to interrupt ..... What is MC? New at this stuff, still learning.
Metal-clad.
Around here, people call it BX... I'm not sure why.
Looks like this:
http://www.copper.org/applications/electrical/pq/images/mc_cable.jpg
edit: oops! there's a 2nd page...
Frenchie where you been?
Spent the summer in Italy, working for my wife's ex-emplyers / surrogate family.
There was a thread at the other place:
http://forums.jlconline.com/forums/showthread.php?t=43392&highlight=frenchie
and I posted some more pictures, here:
http://forums.jlconline.com/forums/showthread.php?p=417128&highlight=siena#post417128
and a little thread, here:
http://www.terrylove.com/forums/showthread.php?t=23681&highlight=italy.
PabNYC
11-21-2008, 11:24 AM
if the issue is BX and someone THINKS it's MC then we could have a problem in older homes because MC is not BX and the issues of improper use of the outer jacket of BX is wide spread and is a different issue...The original OP was in my opinion refering to new MC in a new installation.........BX is very different than MC of today.
In this case it is MC, not BX but what is the difference? BX has no separate ground wire and the metal sheath is carrying the ground but is there anything else that I am just not understanding??
Thanks to everyone who replied on this thread.
Pab