EMT Connector

[Alwayslearningelec]

Would you still need separate plastic busing if using an insulated connector?
Need the busing with regular non insulated connector.

 

[Ponchik]

I assume you are talking about larger than 6 conductors?

 

[Alwayslearningelec]

I assume you are talking about larger than 6 conductors?

Why does that matter?

 

[infinity]

Why does that matter?

#6 and smaller does not require a bushing on an EMT connector. Although they do not require an additional bushing IMO insulated throat connectors are terrible when pulling larger conductors.

 

[Alwayslearningelec]

#6 and smaller does not require a bushing on an EMT connector. Although they do not require an additional bushing IMO insulated throat connectors are terrible when pulling larger conductors.

So no bushing at all on EMT( just connector) for #6 and smaller and no busing required when using insulated throat connectors?

 

[don_resqcapt19]

So no bushing at all on EMT( just connector) for #6 and smaller and no busing required when using insulated throat connectors?

That is correct.

 

[iustacould]

300.4(G) in the 17

 

[farmantenna]

have to chuckle when you see 1/2" or 3/4" emt with 12s and 10s and bushings.

 

[acin]

I guess you saw my panel. I learn so much on this forum.

 

[Jolted]

have to chuckle when you see 1/2" or 3/4" emt with 12s and 10s and bushings.

Why? I don’t normally use them, but it helps prevent wire damage when pulling sometimes, and overall, I’d consider it an upgrade.

 

[Fred B]

have to chuckle when you see 1/2" or 3/4" emt with 12s and 10s and bushings.

I see the reference in 300.4 (never noticed before), 99.9% of the time you're pulling 10s or smaller in 1/2" or 3/4". So when would you use the Bushings on a 1/2" or 3/4" emt? They make them. If you do a calc on #4 thhn copper 1/2" emt would only allow 1 #4 and 2 on 3/4". (Southwire fill calculator) So that would preclude use of 1/2" or 3/4" emt on the majority of installations of #4 or larger.
Had an inspector that wanted them on all 1/2" and 3/4" connectors regardless of wire size so I've just always did.

 

[abrace]

Had an inspector that wanted them on all 1/2" and 3/4" connectors regardless of wire size so I've just always did.

I require bushings on all my jobs, regardless of pipe size. I just think its a better product.

 

[Carultch]

Why does that matter?

The NEC draws a line on not requiring bushings or insulated throats on connectors, as long as conductors are #6 and physically smaller. It doesn't apply to cut/threaded conduit/nipples where bushings are always required, but rather it only applies to connectors specifically. Could be compression connectors, set-screw connectors, or PVC male adapters. Any time a conduit terminates with a fitting that is analogous to a PVC male adapter, it allows you to not add a bushing for #6 and smaller wires. I don't agree with this rule, and I specify to always equip conduit terminations with exposed male threads, with either a bushing or an insulated throat, as all wire is subject to abrasion as it exits the raceway, regardless of size.

The insulated throat counts as the equivalent function of a plastic bushing or the plastic insert of a metal bushing. It is a way to protect the wire from long-term abrasion as it thermally expands and contracts. If the insulated throat on the fitting *didn't* count as equivalent to the plastic bushing, there would be no point in even manufacturing insulated throat connectors in the first place. Everyone could instead use a standard connector and a plastic bushing, if you'd ultimately have to add a plastic bushing any time it is required.

 

[Carultch]

I see the reference in 300.4 (never noticed before), 99.9% of the time you're pulling 10s or smaller in 1/2" or 3/4". So when would you use the Bushings on a 1/2" or 3/4" emt? They make them.

If terminating RMC nipples or RMC threaded ends on enclosures, you need a bushing regardless of wire size. Hence why there is a market for 1/2" and 3/4" plastic bushings.

One example of where you might see #4 wire in a 1/2" or 3/4" conduit, is when it is the GEC, as the sole wire routed within the conduit.

 

[SSDriver]

. I don't agree with this rule, and I specify to always equip conduit terminations with exposed male threads, with either a bushing or an insulated throat, as all wire is subject to abrasion as it exits the raceway, regardless of size.

I agree with everything you said except for this. I believe the intent of putting bushings on fittings with #4 and larger wire is due to the stiffness (lack of flexibility) of the larger conductors and therefore they will get damaged with little force on the wire while making terminations or vibration. Where smaller conductors will bend easily along other portions of the wire to not have an issue. This really isn't an issue with 99.9% of the installations of EMT, FMC, LFMC connectors where #6 and smaller conductors are installed unless someone really pulls hard on the wire or jams/over fills the box and damages wire. With larger wire it is much easier to damage the insulation when closing a box or when manipulating the wires onto termination points. The wire won't just bend or flex and can easily put pressure on the insulation and the metal fitting, this is not an issue with smaller wire as it will just bend somewhere along its length if box fill and length of conductor is to code.

 

[kwired]

One example of where you might see #4 wire in a 1/2" or 3/4" conduit, is when it is the GEC, as the sole wire routed within the conduit.

and you don't need to protect the conductor insulation in that instance, or even have insulation on the conductor for that matter

 

[Carultch]

and you don't need to protect the conductor insulation in that instance, or even have insulation on the conductor for that matter

True. In many instances, the NEC allows a GEC to be external to the system of raceways and enclosures.

One reason you might enclose it in conduit, is as a deterrent to copper theft. Another reason you might do that, is where subject to vehicular traffic, or protection from the environment.

 

[kwired]

True. In many instances, the NEC allows a GEC to be external to the system of raceways and enclosures.

One reason you might enclose it in conduit, is as a deterrent to copper theft. Another reason you might do that, is where subject to vehicular traffic, or protection from the environment.

Unless a pretty small conductor, a raceway isn't going to provide much physical protection to a GEC, most the time it just a neater looking install.

Vehicular traffic? Even RMC won't provide enough protection in some cases.

 

[don_resqcapt19]

The language in the 2020 code in 3004.(G) list item 2 does not reflect the intent of the code.
The product standards require all listed fittings to have a smoothly rounded surface or edge, so the actual language eliminates the code requirement for a bushing where using a connector no matter what the wire size may be. The intent of the new list item (2) was only to permit the use of all metal bushings with a smoothly rounded surface, but the language was not correctly written.

The change was intended to permit the bushings shown below because they do protect the conductors as well as an insulating bushing and maybe even better as the all metal bushing will not be damaged when the wires are being installed. A damaged bushing may in turn cause damage to the conductor insulation.

 

[infinity]

The language in the 2020 code in 3004.(G) list item 2 does not reflect the intent of the code.
The product standards require all listed fittings to have a smoothly rounded surface or edge, so the actual language eliminates the code requirement for a bushing where using a connector no matter what the wire size may be. The intent of the new list item (2) was only to permit the use of all metal bushings with a smoothly rounded surface, but the language was not correctly written.

I agree that the new wording with the addition of item (2) is terrible for the reason that you noted. I'm guessing that someone thought that an EMT connector does not meet the smoothly rounded edges part.