Question about using EMT/conduit for exposed work
#1
12-05-15, 01:40 PM
Question about using EMT/conduit for exposed work
Hello - I am remodeling a room in our basement and have a question about what is "allowed" when using EMT (conduit). I think my plan will be OK but I'm hoping to get a little input from people with more experience than myself.
The room has cinder block walls and one of the previous owners had just run BX (the old armor clad stuff) down to the various switch boxes and receptacles. All this is getting replaced (running all the way back to the breaker panel), and instead of just running new armor clad cable I thought it would look nice to run Romex (NM cable) inside a length of 1/2" EMT (I'm going for an industrial look). My question is this. Do I need to run the EMT all the way from the switch/receptacle box to the breaker panel, or can I just run a short section of EMT from the switches/receptacles up into the ceiling and leave it be?
I hope I'm explaining this OK.
The room has cinder block walls and one of the previous owners had just run BX (the old armor clad stuff) down to the various switch boxes and receptacles. All this is getting replaced (running all the way back to the breaker panel), and instead of just running new armor clad cable I thought it would look nice to run Romex (NM cable) inside a length of 1/2" EMT (I'm going for an industrial look). My question is this. Do I need to run the EMT all the way from the switch/receptacle box to the breaker panel, or can I just run a short section of EMT from the switches/receptacles up into the ceiling and leave it be?
I hope I'm explaining this OK.
#2
12-05-15, 02:41 PM
My question is this. Do I need to run the EMT all the way from the switch/receptacle box to the breaker panel
can I just run a short section of EMT from the switches/receptacles up into the ceiling
Last edited by ray2047; 12-05-15 at 02:56 PM. Reason: Clarification.
#3
12-05-15, 02:45 PM
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If you run EMT then you really need to learn how to make consistent "box offsets" in the conduit so the conduit lays flat on the surface. You can buy a tool for making the offsets but it is expensive, used to be around $60-$80 years ago but is probably double that these days. You could use offset fittings but they are significantly more expensive and look amateurish.
When using conduit is is best to use individual conductors and not cable (type NM) as it is difficult to near impossible to run any significant length of cable through conduit that has bends. Running type NM through box offset fittings is almost impossible due to the restricted opening through the fittings.
IF you go the conduit/cable route you do not need to use continuous conduit but could, perhaps, leave the conduit open-ended above a drop ceiling and then run just the cable to the circuit breaker panel. If you use individual wires then the conduit must be continuous.
When using conduit is is best to use individual conductors and not cable (type NM) as it is difficult to near impossible to run any significant length of cable through conduit that has bends. Running type NM through box offset fittings is almost impossible due to the restricted opening through the fittings.
IF you go the conduit/cable route you do not need to use continuous conduit but could, perhaps, leave the conduit open-ended above a drop ceiling and then run just the cable to the circuit breaker panel. If you use individual wires then the conduit must be continuous.
#5
12-05-15, 03:51 PM
The graphic pcboss posted is more or less what I was planning on doing. The NM cable will exit the EMT at a height of about 7'. Is there some kind of bushing or other fitting that can be used at the top end to secure the NM cable?
In another space where I ran EMT I actually DID use THHN cable. Even then it was still a little challenging pulling them all through the bends, offsets, etc. This is going to be a straight shot and a relatively short length (maybe 3' max).
Furd I hear what you're saying about the offsets for the boxes. But does the EMT have to lay FLAT on the wall? I was thinking I'd use a conduit clamp. That way I won't have to create offsets (that tool is cool but I don't want to own one for $300+) or use those fittings (and I agree those look lame).
Thanks for the input guys!!!
In another space where I ran EMT I actually DID use THHN cable. Even then it was still a little challenging pulling them all through the bends, offsets, etc. This is going to be a straight shot and a relatively short length (maybe 3' max).
Furd I hear what you're saying about the offsets for the boxes. But does the EMT have to lay FLAT on the wall? I was thinking I'd use a conduit clamp. That way I won't have to create offsets (that tool is cool but I don't want to own one for $300+) or use those fittings (and I agree those look lame).
Thanks for the input guys!!!
#6
12-05-15, 03:59 PM
Group Moderator
We call them fromto's but they're actually called screw type combination couplings.
They actually make a fitting called an offset EMT connector... for connecting EMT to boxes.
They actually make a fitting called an offset EMT connector... for connecting EMT to boxes.
Last edited by PJmax; 12-05-15 at 04:37 PM. Reason: Added bushing per PC boss
#7
12-05-15, 04:23 PM
Forum Topic Moderator
The cable needs to be secured as shown. It does not necessarily need to be clamped to the conduit. A bushing is needed to provide a smooth surface.
#8
12-06-15, 05:27 AM
The NM cable will be secured to the joists with staples. I'll pick up some bushings next time I'm at the store.
Thanks for all of the input everyone. Great forum!
Thanks for all of the input everyone. Great forum!
#10
12-07-15, 07:38 AM
You can make a decent offset with a standard 1/2" conduit bender ($30) from a standing position. Place the bender with the curved side up, notch away from you. Slot the conduit into the notch right up to the end; the length of conduit will be up over your shoulder. Pull it down slightly to put a mild bend in the pipe. Rotate the pipe 180 degrees and slide it down the bending notch an inch or two. Pull the conduit down again and make an equal bend in the opposite direction. Offset bend complete. Conduit is $2 per length. Buy an extra length or two and practice making bends.
This bend is more extreme than a box offset, but demonstrates the technique (random image via GIS):
This bend is more extreme than a box offset, but demonstrates the technique (random image via GIS):
#11
12-07-15, 08:00 AM
I actually already own both 3/4 and 1/2" benders and have come to the conclusion that this isn't an art form I want to learn. 
Thanks again for the input everyone!
Thanks again for the input everyone!
#12
12-07-15, 10:12 AM
Member
If you use a conduit hanger type clamp (commonly called a minnie), no offset is needed when entering a box, the conduit just goes straight into the box connector.
https://www.galco.com/buy/Crouse-Hinds/0B
https://www.galco.com/buy/Crouse-Hinds/0B
#14
12-07-15, 11:58 AM
Member
