Electrical circuit and conduit question?

[Alan Tolchinsky]

Hi All, When running multiple circuits through conduit, like a 220 and 120 volt circuits, how do you keep them separate? Do you pull them all at the same time if they're going to the same general area? How do you keep all the wires identified for each circuit? Thanks

[Steve Clardy]

I pull all at the same time.
Black tape works for markers. One piece wrapped on one wire, two pieces wrapped on another wire, etc etc.

[Tyler Howell]

Different colored wires!!!
I also will mark them with tape or Magic marker. Pulling multiple runs can cut the insullation of the existing wires. DAMHIKT

[Alan Tolchinsky]

Thanks Tyler and Steve. Your ideas make a lot of sense to me. Alan

[Steven Wilson]

When I'm done I get the wife and we check for continuity on each wire (i.e. using conduit as ground I have my wife touch each wire end to conduit and I check it at the end of the run with a multimeter to see if there is continuity between the wire and the conduit). I then label each wire and write down what it's for (just a habit from wiring recording studios). Just make sure when you're installing everything to leave enough room in your conduit and your boxes (think big boxes).

[Alan Tolchinsky]

I like that trick using the conduit as part of the circuit for checking the identity of each wire. Very cool. Thanks!

[Larry Fox]

Also, any electrical supply store sells little numbered / lettered stickers specifically for this purpose. Problem is really bad when pulling control wiring or something like that where there are many many smaller guage wires all of the same color going through a large conduit. Always used the numbered / lettered stickers and never had a problem.

I also like the idea of using the conduit as a conductor when ringing out the wires. I have always done it using pairs of wires which can be a pain.

[Jeff Horton]

Something to consider when running wires together in one conduit. The hot wire will cause an induced voltage in a dead wire. While it's probably not substantial none the less it is still very real voltage there.

I am not sure if 110V and 220V together present a problem. I just know it can provide a nice shock and confuse the heck out of you when your troubleshooting a problem.

[Jim Becker]

I am not sure if 110V and 220V together present a problem. I just know it can provide a nice shock and confuse the heck out of you when your troubleshooting a problem.
In both 120v or 240v circuits (North America...different in EMEA, etc.), a single hot conductor only has 120v on it...but it's important to know which wires are "hot" by either consistent colors or proper labeling...or better yet, both.

[Alan Tolchinsky]

Yeah, that makes sense. You need two 120 volt lines to make a 220 so I guess I'm thinking of separate circuits i.e. 120 volt and 220 volt.

[Jim Becker]

Alan, what you need to deal with is insuring that you have "enough conduit" for the number of conductors you intend to run through it. There are rules for this. (I can't recite them...I'm sure others can) Assuming you have your conduit sized appropriately, I'd personally run separate conductors for the 240v and 120v circuits to keep things simple to manage in the breaker panel. I just don't like dual voltage situations with wiring unless it's four conductors to an appliance requiring dual-voltage. That's a personal preference that I followed in my shop.

[Steven Wilson]

In addition to the conduit fill calculation that Jim mentioned you also have box fill calculations to deal with. This comes into play if you have a run of conduit with outlets spaced on the wall. If you'll have this then you need to consider the volume of the box, volume of the box cover, and the size/number of recepticals. I found the box fill calculations to be more of a limiting factor than the conduit fill calculations. It's an easy calculation to do and it's fairly well explained in the NEC. If you have boxes make them big and get the large volume box covers.

[Alan Tolchinsky]

Thanks Steve and Jim. Those are issues I'll have to investigate. I plan on using quad boxes so I'll have to check one the capacity/volume of these. Thanks for your help.

[Steven Wilson]

go with large quad boxes and don't forget to add in the volume of the cover. If you look around you'll find covers that have their volume stamped on them (cuin), it all helps when you have wires going through the quad and some terminating in the quad with a receptical.