using 4/0 SER in conduit

[Stevenfyeager]

I would like to sleeve 4/0 SER Al in 2" or 2 1/2" PVC for a couple of feet outside from a 400 amp meter base disconnect combo up to a soffit to enter the attic. Is it ok to install this cable in conduit ? Is it too large for conduit fill compliance or is the short distance allow for that fill ? Thank you.

 

[LarryFine]

Use this and tell us your conclusion first (consider stripping the sheath):

Raceway Fill Calculator

A second question is whether you need an outside disco.

 

[Little Bill]

Use this and tell us your conclusion first (consider stripping the sheath):

Raceway Fill Calculator

A second question is whether you need an outside disco.

If it's only a couple of feet (24"), it's not a raceway. it's a sleeve.

 

[marmathsen]

(consider stripping the sheath)

Are you recommending this for fill purposes or some other reason?

If you strip it, is the bare EGC allowed? I think I remember reading that bare conductors are allowed in conduit with insulated contrary to popular belief.

Rob G, Seattle

 

[electrofelon]

I would probably use a female adapter and a clamp connector and strip the SER thus effectively transitioning to individual conductors in a raceway.

 

[rc/retired]

Are you recommending this for fill purposes or some other reason?

If you strip it, is the bare EGC allowed? I think I remember reading that bare conductors are allowed in conduit with insulated contrary to popular belief.

Rob G, Seattle

A bare EGC is allowed in conduit.

Ron

 

[infinity]

Since this is just stubbing into the attic it sounds like a sleeve not a raceway. If it is considered a raceway then for a single conductor the fill is 53%.

 

[electrofelon]

Since this is just stubbing into the attic it sound like a sleeve not a raceway. If it is considered a raceway then for a single conductor the fill is 53%.

I know this comes up a lot and I have never been clear on this or keep forgetting: If the "sleeve" enters a cabinet on the one end, how to we get around the securing requirement for the SER cable? can we just use a TA and bushing and strap the SER just before it?

 

[infinity]

I know this comes up a lot and I have never been clear on this or keep forgetting: If the "sleeve" enters a cabinet on the one end, how to we get around the securing requirement for the SER cable? can we just use a TA and bushing and strap the SER just before it?

IMO it is required to be connected to the end where the cable enters.

 

[Rick 0920]

See NEC Art. 312.5 (C) There are 7 conditions to be met. Also, the inside of a raceway that is run on the outside of a building is considered a wet location. As long as the conductors are listed for wet locations and the 7 conditions are met per 312.5 (C), I would say yes. One of the requirements is that the cable sheath needs to extend into the enclosure at least 1/4"

 

[LarryFine]

Are you recommending this for fill purposes or some other reason?

That, more flexibility, etc. A cable is supposed to be considered a single conductor of the same diameter.

If you strip it, is the bare EGC allowed?

Absolutely. The insulated conductors must be individually marked as suitable for use in wet locations.

 

[LarryFine]

can we just use a TA and bushing and strap the SER just before it?

See post #5.

 

[electrofelon]

See post #5.

That guy is an idiot and I dont trust him at all. But seriously, I think there are two approaches that are being thrown around. One is the "transition" approach where we change from a cable to a conductors in raceway. The other is the 'sleeve" approach. I am fine with the former and dont see any ambiguity. The latter is what I am unclear on and how we get around the securing requirements:

334.30 Securing and Supporting. Nonmetallic-sheathed cable shall be supported and secured by staples; cable ties listed and identified for securement and support; or straps, hangers, or similar fittings designed and installed so as not to damage the cable, at intervals not exceeding 1.4 m (41 ∕2 ft) and within 300 mm (12 in.) of every cable entry into enclosures such as outlet boxes, junction boxes, cabinets, or fittings. Flat cables shall not be stapled on edge. Sections of cable protected from physical damage by raceway shall not be required to be secured within the raceway.

The wording is interesting and perhaps we can call the TA with bushing a fitting and the 12" securing requirement starts there?

 

[Buck Parrish]

I would like to sleeve 4/0 SER Al in 2" or 2 1/2" PVC for a couple of feet outside from a 400 amp meter base disconnect combo up to a soffit to enter the attic. Is it ok to install this cable in conduit ? Is it too large for conduit fill compliance or is the short distance allow for that fill ? Thank you.

What you have described is a very common install. It's done all the time. The tricky part is getting it through a 2 inch LB

 

[wwhitney]

But seriously, I think there are two approaches that are being thrown around. One is the "transition" approach where we change from a cable to a conductors in raceway. The other is the 'sleeve" approach. I am fine with the former and dont see any ambiguity. The latter is what I am unclear on and how we get around the securing requirements:

I think the point is that if your piece of conduit is connected to an enclosure, you are firmly in the transition approach and do not have a sleeve.

If you want to have a sleeve, you need to stop the pipe short of the enclosure and secure the cable to the enclosure as usual. As well as maintain the cable sheathing within the sleeve. [Although I guess you could do a "double transition" approach where you do strip the sheathing within the pipe.]

Cheers, Wayne

 

[Buck Parrish]

I just noticed your in Indiana.
You don't even need conduit as long as it is not likely to get damaged. Just run it exposed.
I always use conduit , but alot of Indiana electricians run it exposed..

 

[petersonra]

Sections of cable protected from physical damage by raceway shall not be required to be secured within the raceway.

Make it a raceway by connecting the PVC to the box. If it is less then 24" long the fill requirements don't apply.

 

[Fred B]

Seems if they had something like this in a larger size like they have for NM it would solve the secure issue as the cable enters or exits a conduit sleeve.

 

[Buck Parrish]

This is two blocks from the inspections office in Teere Haute IN

 

[electrofelon]

I think the point is that if your piece of conduit is connected to an enclosure, you are firmly in the transition approach and do not have a sleeve.

If you want to have a sleeve, you need to stop the pipe short of the enclosure and secure the cable to the enclosure as usual. As well as maintain the cable sheathing within the sleeve. [Although I guess you could do a "double transition" approach where you do strip the sheathing within the pipe.]

Cheers, Wayne

I agree