Need help understanding the code.

[boucher0331]

Is a EMT coupling considered a tubing termination point.:slaphead:

358.30 A

 

[Dennis Alwon]

A coupling is not a termination point IMO.

 

[Dennis Alwon]

Is that why you ask???

 

[boucher0331]

thanks for the feed back!

 

[infinity]

No.

 

[boucher0331]

I am asking out of the 2011 code. I am asking because WE have a debate going on in our class right now. What year are you working from.

What would be another tubing termination example ?

 

[boucher0331]

Thank you again for your help. If any one has any input please speak up.

Thank you!

 

[Dennis Alwon]

I am asking out of the 2011 code. I am asking because WE have a debate going on in our class right now. What year are you working from.

What would be another tubing termination example ?

The year doesn't matter as it has been the same for some time 2005, 2008 and 2011 as well as 2014 has the same wording. Not sure what it was before that

 

[Dennis Alwon]

I think you are caught up in the words of tubing terminations and you are expecting couplings to be in that group. If you look at the examples you see that they are not talking about fittings but rather equipment, boxes etc as termination point. Nowhere does it state 3' from a connector

 

[Gregg Harris]

Thank you again for your help. If any one has any input please speak up.

Thank you!

The verbiage was change in the 1993 code changing the word at the end from (fitting) to (conduit body).

In 1999 the verbiage (or other tubing termination) was added to the end of the section.
There is no definition for tubing termination.

The word fitting included couplings implying that a support was required on each side of the coupling..

This code section has had confusion for years and numerous code change proposals have been presented, the final one that was excepted in 1993 and created the change to the verbiage that is current stated," Coupling support is assured by the third sentence requiring support every ten feet.

There are different examples showing coupling support when using the ten foot requirement and some that do not.

Personally the weakest point of the conduit run is the coupling and it should be clear that it should be required.
Another proposal for clarity is in order.

 

[infinity]

I am asking out of the 2011 code. I am asking because WE have a debate going on in our class right now. What year are you working from.

What would be another tubing termination example ?

The terminations in the graphic provided are pretty good examples. Even though "raceway termination" is not defined by the NEC a coupling that connects two pieces of EMT together does not terminate anything.

 

[jap]

Thank you again for your help. If any one has any input please speak up.

Thank you!

If your debate is wether to put a strap near the joint where the coupling is, to support it,,,,,technically no,,, but I'd throw rocks at any of my guys that didnt.

 

[Dennis Alwon]

The verbiage was change in the 1993 code changing the word at the end from (fitting) to (conduit body).

This is a good point and one I was making above. The NEC is not talking about termination fittings but rather terminations such as in a jb, switchboard, panel, conduit body and any other places subject to termination. The change was to clarify that fittings were not what the NEC was speaking of but rather the point of termination. A surface mounted dryer or range receptacle would be other tubing terminations as mention in art. 358.30(A)

 

[infinity]

In reading this I'm not so sure that I would include a conduit body on the list of termination points.

314.23(E) Raceway Supported Enclosure, Without Devices,
Luminaires, or Lampholders. An enclosure that does not
contain a device(s) other than splicing devices or support a
luminaire(s), lampholder, or other equipment and is sup-
ported by entering raceways shall not exceed 1650 cm 3
(100 in. 3 ) in size. It shall have threaded entries or have
hubs identified for the purpose. It shall be supported by two
or more conduits threaded wrenchtight into the enclosure or
hubs. Each conduit shall be secured within 900 mm (3 ft) of
the enclosure, or within 450 mm (18 in.) of the enclosure if
all conduit entries are on the same side.
Exception: The following wiring methods shall be permit-
ted to support a conduit body of any size, including a con-
duit body constructed with only one conduit entry, if the
trade size of the conduit body is not larger than the largest
trade size of the conduit or tubing:
(1) Intermediate metal conduit, Type IMC
(2) Rigid metal conduit, Type RMC
(3) Rigid polyvinyl chloride conduit, Type PVC
(4) Reinforced thermosetting resin conduit, Type RTRC
(5) Electrical metallic tubing, Type EMT

 

[Dennis Alwon]

In reading this I'm not so sure that I would include a conduit body on the list of termination points.

All that is saying is that the conduit can support the conduit body. IMO, you still need a strap within 3' of the conduit body as shown and the lb is a termination point. Also 358.30 includes conduit body and seems to refer to it when it states " or other terminations"

 

[infinity]

All that is saying is that the conduit can support the conduit body. IMO, you still need a strap within 3' of the conduit body as shown and the lb is a termination point. Also 358.30 includes conduit body and seems to refer to it when it states " or other terminations"

I'm not so sure but what you're saying would make sense. The way I read the exception you could have two supports 10' apart with a conduit body right in the middle providing it's the same size as the trade size of the raceway.

 

[Smart $]

A conduit termination is where, after [proper] installation, wires or cables enter or exit and can be accessed without disassembling the conduit run. Where used entirely for support, the run may not terminate at an enclosure, box, or conduit body.

 

[hurk27]

I'm not so sure but what you're saying would make sense. The way I read the exception you could have two supports 10' apart with a conduit body right in the middle providing it's the same size as the trade size of the raceway.

nope see in red below:

314.23(E) Raceway Supported Enclosure, Without Devices,
Luminaries, or Lampholders. An enclosure that does not
contain a device(s) other than splicing devices or support a
luminaire(s), lampholder, or other equipment and is supported
by entering raceways shall not exceed 1650 cm3
(100 in.3) in size. It shall have threaded entries or have hubs
identified for the purpose. It shall be supported by two or
more conduits threaded wrenchtight into the enclosure or
hubs. Each conduit shall be secured within 900 mm (3 ft) of
the enclosure, or within 450 mm (18 in.) of the enclosure if
all conduit entries are on the same side.

Boxes are not permitted to be supported by rigid raceways
using locknut's and bushings. Enclosures without devices or
luminaires are considered to be adequately supported, provided
the conduit is connected to the enclosure by threaded
hubs and the threaded conduits enter the box on two or more
sides and are supported within 3 ft of the enclosure. A box is
not permitted to be supported by a single raceway.

Exception: The following wiring methods shall be permitted
to support a conduit body of any size, including a conduit
body constructed with only one conduit entry, if the
trade size of the conduit body is not larger than the largest
trade size of the conduit or tubing:

(1) Intermediate metal conduit, Type IMC
(2) Rigid metal conduit, Type RMC
(3) Rigid polyvinyl chloride conduit, Type PVC
(4) Reinforced thermosetting resin conduit, Type RTRC
(5) Electrical metallic tubing, Type EMT

The exception does not relive the requirement of support within 3'

What does not make any sense to me is that the exception totally undoes the rule it was written under, the same goes for 314.23(F)

Second is that it was always required the raceway to be threaded into hubs built into the box or listed hubs and not by lock-nut and or bushings, I don't see where the exception makes a change to this, but it list EMT as one of the wiring methods???

Third, the exception can be applied only if the
trade size of the conduit body is not larger than the largest
trade size of the conduit or tubing, so EMT goes all the way up to 4" so as long as you don't have a 5" conduit body the exception is a go, so you run 1/2" EMT and install a 4" conduit body????

It does not say it has to be the same size of the conduit you ran?

 

[infinity]

nope see in red below:



The exception does not relive the requirement of support within 3'

What does not make any sense to me is that the exception totally undoes the rule it was written under, the same goes for 314.23(F)

Second is that it was always required the raceway to be threaded into hubs built into the box or listed hubs and not by lock-nut and or bushings, I don't see where the exception makes a change to this, but it list EMT as one of the wiring methods???

Third, the exception can be applied only if the
trade size of the conduit body is not larger than the largest
trade size of the conduit or tubing, so EMT goes all the way up to 4" so as long as you don't have a 5" conduit body the exception is a go, so you run 1/2" EMT and install a 4" conduit body????

It does not say it has to be the same size of the conduit you ran?

The heading of that section is "314.23(E) Raceway Supported Enclosure, Without Devices, Luminaries, or Lampholders." IMO the exception negates any requirement for a conduit body to have a support within 3' with the intention that the conduit body is the same size as the conduit.

 

[Smart $]

The heading of that section is "314.23(E) Raceway Supported Enclosure, Without Devices, Luminaries, or Lampholders." IMO the exception negates any requirement for a conduit body to have a support within 3' with the intention that the conduit body is the same size as the conduit.

Say that is true, how do you you get around the requirement to secure the conduit within 3' of a termination (assuming you agree a conduit entering a conduit body represents a conduit termination, and the securing exception to 5' is not applicable)?