Go Back   DIY Chatroom Home Improvement Forum > Home Improvement > Electrical

CLICK HERE AND JOIN OUR COMMUNITY TODAY...IT'S FREE!

Reply
 
Thread Tools Search this Thread Display Modes
Old 01-21-2011, 08:17 AM   #1
I ask the impossible!
 
Join Date: Aug 2010
Location: Royal Oak, Michigan
Posts: 1,069
Rewards Points: 0
Blog Entries: 7
Share |
Default

Conduit for mechanical protection


Okay, I had my rough inspection yesterday, and I have a few issues to resolve before the inspector will pass my project. Kind of irritating because it holds up insulating, and my furnace is not keeping up with the cold we have right now - and I have the ceiling insulated with R30 unfaced batts over top of the joists, just not the walls, and he's okay with that but I do have 2 rows that cover wires, so when I get reinspected I'll pull those down before he gets there Monday.

Anyway, my issues are that
1) I have wires that are accessible in side attics that will be enclosed, I just hadn't finished the framing - doesn't require anything I wasn't already going to do.
2) I have a 4x4 box for 2 switches that the inspector didn't like, it was a pain figuring out a box that would actually fit a 2" deep wall cavity and had 2 gangs, but again on this one I was squeezed for time and went with the only box that would work from the hardware store at the end of the street because I didn't have enough time last weekend to get to the big box store.
3) He wanted me to use fire block in all penetrations through top plates and bottom plates, easy enough to do. Kind of redundant though since NONE of the wall cavities involved are sealed, i.e. they're open on the back to the knee wall attic. I'm fine with just humoring him on this since it's an easy thing to do.
4) I had a surface mounted schedule 40 electrical PVC conduit run for the washing machine. He wants to see EMC.

The last one is where my question comes in. This is a conduit run dedicated for the washing machine and a sink pump. That's easy to take care of. But I want to be thorough so that when he comes back, I don't have to deal with the same issue in a different location just because he didn't look at everything this time.

I have 2 more surface mounted conduit runs of 2' long going out of the wall in the same room and straight up through the ceiling. These are in the middle of the run and they're above the water heater, I did this because it's a difficult area to access because of the water heater and the wall is a formerly exterior wall so there are a lot of layers to go through to go inside the wall. This is the middle of 2 cables that are secured to the top of joists over the utility room and fished through walls in the kitchen, and he passed rough inspection for the kitchen.

In short, pulling the cable out would be a huge pain in the ass, and would probably keep me from being able to take care of everything to be ready for inspection Monday, and to get inspection Monday I need to request it today.

So, the way I see it, my options are to either leave the PVC or do splices inside a junction box at the ceiling and at the wall penetration with EMC between the junction boxes. I'm not sure I'd have enough wire to get 6" x2 inside the junction box, and if I do and can do this with 1 splice I will, but for now I'm planning based on needing to do 2 splices.

Preferred would be to not have to splice, so the question is would a 2' conduit run like this be considered subject to mechanical damage and thus require the EMC?

WillK is offline   Reply With Quote
Old 01-21-2011, 08:40 AM   #2
Licensed electrician
 
Join Date: Sep 2007
Location: Maryland
Posts: 7,596
Rewards Points: 26
Default

Conduit for mechanical protection


Is there any way to post a pic of the area in question?

What didn't the inspector like about the 2 gang box?

IMO, not that it counts, the PVC would have been sufficient down the wall for the protection of the cable for the washer.

__________________
Answers based on the National Electrical Code. Local amendments may apply. Check with your local building officials.
Jim Port is online now   Reply With Quote
Old 01-21-2011, 09:25 AM   #3
I ask the impossible!
 
Join Date: Aug 2010
Location: Royal Oak, Michigan
Posts: 1,069
Rewards Points: 0
Blog Entries: 7
Default

Conduit for mechanical protection


My digital camera quit last Friday, gears in the mechanism for the mechanical zoom have stripped so it shuts down when turned on because it can't open the lens.

On the box, I had installed the metal box and mud ring cover shown below, he wanted a box with the tabs for attaching to the stud and he complained that the metal box needed to be bonded to the ground - correct me if I'm wrong, but doesn't grounding the switch provide a path to ground for the box? At any rate, I prefer to avoid the issue with a plastic box, so I'm going to use the plastic box and cover shown below.
Attached Images
    
WillK is offline   Reply With Quote
Old 01-21-2011, 11:08 AM   #4
Member
 
Join Date: Jun 2007
Posts: 3,506
Rewards Points: 0
Default

Conduit for mechanical protection


Your original question is way to long to read. So I will answer the last question concerning the boxes you picture.
Your inspector is giving you his interpretation of the code requiring boxes to be supported. The metal box can be supported to either metal or wood studs as it is and the mud ring is correct for 2 gang application. There are more than one way to secure a metal box and the code does not require the mounting ears. I use a length of 2x4 for wood or a length of metal stud for metal. Sometimes I just use the two small holes on the side. I only do this when I am using conduit. I have NEVER used a box with mounting ears. They cost to much.

The plastic box and ring are self explanatory. Don't argue with the inspector unless its something major. Like if he was requiring you to use boxes with flanges throughout a complete structure. I would fight that until. One box is no big deal.
J. V. is offline   Reply With Quote
Old 01-21-2011, 12:25 PM   #5
Licensed electrician
 
Join Date: Sep 2007
Location: Maryland
Posts: 7,596
Rewards Points: 26
Default

Conduit for mechanical protection


Pretty bogus reason to disallow that mounting method for the box. You would still need to bond the box with a grounding conductor and a ground screw.
__________________
Answers based on the National Electrical Code. Local amendments may apply. Check with your local building officials.
Jim Port is online now   Reply With Quote
Old 01-21-2011, 11:10 PM   #6
I ask the impossible!
 
Join Date: Aug 2010
Location: Royal Oak, Michigan
Posts: 1,069
Rewards Points: 0
Blog Entries: 7
Default

Conduit for mechanical protection


Okay, for a work related project I have my work camera with me, so I have some photos relating to the question for which I really need the feedback. The box is kind of a nuisance that's questionable if there's anything actually against code, but not worth arguing so I'm just making the change. But man, what does bother me is the fact that I'm stuck holding off on insulating, the heater can't keep up and it's getting cold inside, and it has to be like this until Tuesday afternoon, which is the next day the electrical inspector works.

Pictured below is the run from the framing for the subpanel to the duplex receptacle for the washing machine and sink pump, which the inspector specifically pointed out that schedule 40 PVC conduit needs to be metal for protection from mechanical damage. He also said it needs to be secured, which it is so I don't know why he was pointing it out, I just assume he wanted me to be sure when I replaced it with EMT that I secured it.

I don't mind changing that one, again if nothing else just to humor the AHJ - that one isn't that difficult to change.

The real question for the other 2 pictures. These are the 2 other locations I have used PVC conduit. One is a 1-1/2" and a 3/4" run from the main panel to the ceiling, not too hard to change. The other is 2 runs from the ceiling down 18" to enter into the wall. I'd have to make 2 splices in each cable because I don't have 12" of free length and it's the middle of 30' or so, and the fishing and securing of these cables was a lot of work.

The question would be if I have a leg to stand on to leave this particular run as schedule 40 PVC? I mean, I think I get that schedule 40 isn't approved for protection from severe mechanical damage, and I can see that 3-4' off the ground I could ram a appliance into it while moving it around, but maybe the top 18" near the ceiling is a bit remove from anywhere any damage is going to happen unless something launches like a rocket.

Or should I go ahead, cut the wire and make my splices in junction boxes connected my EMT?
Attached Thumbnails
Conduit for mechanical protection-img_7636.jpg   Conduit for mechanical protection-img_7637.jpg   Conduit for mechanical protection-img_7638.jpg  
WillK is offline   Reply With Quote
Old 01-21-2011, 11:32 PM   #7
I ask the impossible!
 
Join Date: Aug 2010
Location: Royal Oak, Michigan
Posts: 1,069
Rewards Points: 0
Blog Entries: 7
Default

Conduit for mechanical protection


The biggest problem for me is the timing of this... Rough inspection failed on Thursday, so after this I go to work for the last couple hours of the day, I come home (takes longer because of freezing rain), we have dinner, give the kids their bath, by the time I get my list of materials together, it's 5 minutes before the big box stores close, and it's about a 5 minute drive to get there. So I can't even get materials Thursday, even if I had been able to schedule the re-inspect Friday I wouldn't have been ready. Since the inspector doesn't work Monday, I'm stuck without insulation Friday, Saturday, Sunday, Monday and Tuesday before I get inspected, and even if I pass I don't have the time on evenings I would on a weekend.

What's worse is the weather outside is cold, and that was less of an issue before when the least insulated room upstairs was closed off by a door. The very last thing I had done preparing for rough inspection was the reframing of the wall that had the door because I'm putting in a larger door. So now I have no door and a huge escape path for the heat in the rest of the house. I'd rather have been able to get that room insulated so I could hang the door after the floor levelling project that's likely to skew the door frame a little.

At this point it is what it is, I just want to do what I need to do so I pass on Tuesday.

WillK is offline   Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
PVC conduit - custom offset or bending tns1 Electrical 25 08-29-2011 05:56 PM
Buried gas pipe in conduit WillK Plumbing 4 01-07-2011 12:50 PM
How to plug unwanted and leaking conduit? gernith General DIY Discussions 6 08-08-2010 12:09 PM
Warm and Noisy Electrical Conduit Intravartolo Electrical 4 07-26-2010 01:46 AM
Chicago Conduit Rules Wrigleyville Electrical 6 01-28-2010 06:49 PM




Top of Page | View New Posts

Copyright © 2003-2014 Escalate Media. All Rights Reserved.