emt vs ent

Could someone please clarify EMT vs ENT for me?

If I go to a big box store and get metal conduit that uses compression fittings, is that ENT?

If I find metal conduit with threaded ends, is that EMT?

If I want to run a cable down the concrete wall of my garage or basement to a switch or outlet, do I need to use EMT or is ENT ok? Is EMT more damage resistant?

My understanding is that I can use NM cable, just need a straight run of conduit to protect the cable until I am up in the joists and that I do not have to derate the cable. In that case, either one is probably easy enough to work with. All I need is the right fitting for one end and a hacksaw (and file to ease sharp edges?) for the other.

 

EMT is electrical Metalic Tubing. ENT is Electrical Nonmetalic Tubing.

One is made of metal, the other is not.

And you will need a connector to go into the box at the bottom and a connector and bushing at the top, or they make a slide on bushing that works without a connector if you can find them.

 

Whether or not you need to use either of these on a basement wall is up to the inspector. Sometimes they allow a wooden runner down the wall with the cable stapled directly to the runner.

If you do need protection for the cable then yes, you can place the NM inside the conduit without derating of any sort required. At the ceiling end of the conduit just use a bushing to cover any sharp conduit edges and protect the cable as it leaves the conduit.

 

Ok, it always makes life easier to know what the acronym stands for.

I guess my real question is whether the metal conduit with the compression fittings is different than the metal conduit with threaded ends and whether that matters in a case like I described.

 

Thanks, but I've mostly decided it is a good idea, as long as it's permitted, even if it's not required. I can remember some of the idiot things I did as a child so I'm always looking for a little more to keep my kids out of danger as they grow up.

 

Yes, though are two different (actually 3) types of conduit as well.

EMT uses either compression or set screw fitting.

the threaded conduits come in two flavors

IMC- intermediate metal conduit
RMC- rigid metal conduit.

Just like it sounds, IMC is between EMT and RMC as far as the thickness of the metal. This conduit can be threaded or there are non-threaded connectors and couplings, which are also available for RMC as well.

They each offer a level of protection higher than the one prior.

 

ENT is often called smurf tube, because it is made from a flexible blue corregated plastic. In my experience, it is not used much for line voltage as it offers virtually no physical protection to the conductors and is tough to pull wires through without snagging. Telecom and data cables are often installed in ENT.

 

That's my experience too. Lots of cable lube. Funny that the manufacturer hypes the ribbing that reduces contact, and by inference friction, by around 50%.