Does the Code book say anything about using Unions?

[Eddy Current]

I don't think it does, does it?

 

[480sparky]

Unions as in ericsons?

Unions as in IBEW?

Unions as in civil unions?

 

[kwired]

As long as the union is approved for use with the raceway why should code see it any different than any other fitting for the raceway?

 

[Eddy Current]

Rigid union couplings.

 

[kwired]

Rigid union couplings.

You said it right there ... it is a coupling, just happens to be more than one piece to make up the whole thing.

 

[Eddy Current]

Does it mention it in the RMC section or does it just say coupling?

 

[infinity]

Some old timers will tell you not to use them. The NEC doesn't care as long as it's an approved/listed fitting.

 

[Volta]

Some old timers will tell you not to use them. The NEC doesn't care as long as it's an approved/listed fitting.

And that's more a matter of pride than a concern for low-impedance.

 

[hurk27]

Rigid union couplings.

We are talking about the 3 piece Erickson couplings right, not regular galvanized plumbing unions that plumbers use? the first is listed for the purpose, the second is not.

Here is a three piece Erickson coupling:

 

[stew]

I have used 3 piece explosion proof types in the past. They are used extensively with propane tank pump motors. No reason they couldnt be used in a rigid run. they are listed fittings.

 

[ronaldrc]

Someone told they put a end to what use to be our automotive Business.

Oh wait a minute,I'm sorry you meant a 3 piece coupling.

 

[renosteinke]

Automotive unions?

 

[elohr46]

Some old timers will tell you not to use them. The NEC doesn't care as long as it's an approved/listed fitting.

actually worked at a chemical plant that would not allow them, in some cases we would have to build the raceway on the ground and have 3 or 4 electricans lift it in place.

 

[iwire]

actually worked at a chemical plant that would not allow them, in some cases we would have to build the raceway on the ground and have 3 or 4 electricans lift it in place.

Got to keep everyone working ....

 

[ronaldrc]

Automotive unions?

:rant::rotflmao:

 

[sameguy]

When used in wet areas, outside, which end up on vertical runs?

 

[iwire]

When used in wet areas, outside, which end up on vertical runs?

Either, standard RMC couplings are not watertight anyway.

 

[jumper]

Either, standard RMC couplings are not watertight anyway.

That does not bother me as long as my conductors are.

 

[kwired]

I have used 3 piece explosion proof types in the past. They are used extensively with propane tank pump motors. No reason they couldnt be used in a rigid run. they are listed fittings.

That works but they are at least 3-4 times the cost for small sizes like 1/2 inch to 1 inch. They are also used a lot at fuel dispensing units at the gas station, or at the pump where remote pumps are used.

 

[renosteinke]

I can't speak for others, but I would never consider a union as a substitute for a coupling.

I use unions in those situations where it is simply not possible to tighten the threads on the pipe into a threaded hub. For example, where two pipes enter the same side of the enclosure. Another example might be where a piece of equipment might need periodic removal; gas pumps are such an example.

This is why unions are most often found in 'hazardous location' piping; I don't think the compression connectors are approved for such use. It also looks a bit silly to add a compression fitting to a threaded hub.

The NEC does not discuss any particular fittings. One is free to use any listed components in any manner, any combination. One could make a three-mile wire run of nothing but handy boxes, running thread, locknuts, and bushings, should one wish to do so.