ENT or EMT

[petersonra]

If someone is contemplating ENT or EMT vs NM it looks automatically like exposed wiring. In wall prices are all over the place right now but I can’t seriously believe NM is that special. If it’s DIY where labor is $0 then maybe ENT makes sense. AC/MC and EMT will cost more in materials. If it’s contracted then labor cost vastly exceeds the material cost and the only guy not happy is whoever is eating the cost increase.

Running separate distribution panels maybe makes sense but I doubt it. First you are adding at least one additional breaker and possibly more if you use one per sub panel. So that’s half an NM roll. The wiring to the sub panel is larger so it costs more per foot vs however much branch wiring you save. If diversity works out you save money but if you are say using a 60 A feeder to feed four 15 A branches, the increased wire size is going to cost more than the smaller branches. Plus the cost of the panels that is about the price of a roll of NM. So without running numbers it seems like a wash at best.

In controls we often look at all home runs to giant overstuffed control panels vs remote IO. Almost every time the giant control panel wins in terms of pricing for initial installs. But over the long term there is a big difference between troubleshooting and repairing 10 feet of cable to a remote IO panel and hundreds of feet of home run, particularly if the home run is a multi conductor cable and gets damaged.

Interesting. Just about every time I have done the numbers remote IO comes out cheaper. The thing is you still need the IO and everything else the only thing that's added is a remote IO adapter usually and they're relatively cheap. While electrician labor conduit and wire is extremely expensive.

 

[readydave8]

I wired several jobs with "ENT" back in the '80s', restaurant and c-store and bed & breakfast are 3 I remember, and have managed to avoid ever since, mostly due to pulling wire through it

 

[kwired]

If someone is contemplating ENT or EMT vs NM it looks automatically like exposed wiring. In wall prices are all over the place right now but I can’t seriously believe NM is that special. If it’s DIY where labor is $0 then maybe ENT makes sense. AC/MC and EMT will cost more in materials. If it’s contracted then labor cost vastly exceeds the material cost and the only guy not happy is whoever is eating the cost increase.

Running separate distribution panels maybe makes sense but I doubt it. First you are adding at least one additional breaker and possibly more if you use one per sub panel. So that’s half an NM roll. The wiring to the sub panel is larger so it costs more per foot vs however much branch wiring you save. If diversity works out you save money but if you are say using a 60 A feeder to feed four 15 A branches, the increased wire size is going to cost more than the smaller branches. Plus the cost of the panels that is about the price of a roll of NM. So without running numbers it seems like a wash at best.

In controls we often look at all home runs to giant overstuffed control panels vs remote IO. Almost every time the giant control panel wins in terms of pricing for initial installs. But over the long term there is a big difference between troubleshooting and repairing 10 feet of cable to a remote IO panel and hundreds of feet of home run, particularly if the home run is a multi conductor cable and gets damaged.

Looking at online prices for one my supply houses, if you want to run a single two wire (with ground) circuit:

NM is $.964/foot

MC is $.863/foot MCAP (sheath is EGC) is about same as regular MC

1/2 EMT is .86
12 THHN/THWN is .247
use raceway for EGC and figure two conductors you are at 1.35 foot, plus you need additional couplings you don't need for other methods.

Factor in some issues with your application and every one those methods can have its reasons to be the one to use, as base material cost is all in similar range.

The EMT maybe doesn't look very high at all if you have a mostly long straight run and multiple circuits pulled through it and is easy to strap to a surface or on top of ceiling joists or similar.

 

[James L]

Looking at online prices for one my supply houses, if you want to run a single two wire (with ground) circuit:

NM is $.964/foot....

1/2 EMT is .86
12 THHN/THWN is .247
use raceway for EGC and figure two conductors you are at 1.35 foot, plus you need additional couplings you don't need for other methods.

The takeaway:
EMT costs as much empty as what NM costs

 

[kwired]

The takeaway:
EMT costs as much empty as what NM costs

Is a little less if running two 2 wire circuits, then labor starts to factor more heavily in any decisions. Run three circuits or even MWBC's in the raceway and it gets even more "efficient" as long as the raceway isn't too difficult to run.