SER connector

[paul32]

What do you like to use for SER connectors. Most of what I've been able to find are like this:

http://www.aifittings.com/images/c3_842im.gif

Arlington also has these:
http://www.aifittings.com/images/c71008im.gif http://www.aifittings.com/images/c71008ld.jpg

http://www.aifittings.com/images/c71001.jpg
These latter I think are for SEU only. The round one seems to have an oval opening. Is there anything else for SER?

I like the black button type for NM cable, but don't think there is that type for larger cable. I'm more concerned about connecting to the back of the outside main. I know the bottom knockouts of the NEMA 3R don't need to be water tight, but the first type above doesn't seem right to me. What do you use? And the connector would penetrate the outside wall, and seems harder to caulk than around the cable. Or is there some product to use instead of caulk? Maybe duct seal.

[mdshunk]

I'm not sure what the question is exactly. For the top of the meter can, in the hub, use the type with the rubber gland. For the back or the bottom, us a regular NM connector. I can't say that I've ever caulked a connector penetrating the back of the can.

[paul32]

Thanks for responding. I'll try to be more clear. My questions are:
1. Are there other types of connectors for SER cable?
2. What kind of connector is used for SER going in the back of the 3R enclosure?
3. How do you keep water out of the building? The only thing that I have thought of is caulk or duct seal put on from the inside after the enclosure and cable are installed.

[George Stolz]

Originally posted by paul32:
Thanks for responding. I'll try to be more clear. My questions are:
1. Are there other types of connectors for SER cable?
2. What kind of connector is used for SER going in the back of the 3R enclosure?
3. How do you keep water out of the building? The only thing that I have thought of is caulk or duct seal put on from the inside after the enclosure and cable are installed. I use these in the top of the panel: :(

Caulking around the backside is a good idea.

[ July 26, 2005, 11:31 PM: Message edited by: georgestolz ]

[George Stolz]

I'm bumping this thread.

I recently was told that in a local jurisdiction, they are going to start enforcing 312.5(C), meaning that our standard practice of slapping a PVC MA into the back of a metermain to protect our SER from the knockout was no longer acceptable.

We figured out a method for using these...
:confused:

[electricmanscott]

I Have always used the standard connector shown. Don't know if I have ever had to go into a 2x4 wall space as most homes here have basements.

[jbwhite]

this is a case of artfull dodging. depending on the building construction i have used everything from running conduit into the building and using individual conductors, to having the carpenter build the wall out deeper to make the required bending space.

having a basement handy is nice, if the panel is going there, because you can use a couple short stalks of conduit and an LB then mount the panel directly inside the building.

[mdshunk]

I use the regular 2", 2 screw romex connector installed backwards (locknut on the outside of the box) when I need to get 200 amp SER inside a 2x4 wall. I know some of my guys use a 2" blue snap in bushing. This protects from abrasion, but provides no clamping. Yes, this is an area that sure could use a new product solution. Arlington Industries, are you listening?

[George Stolz]

Scott, so you pipe out of the metermain down the wall into the basement below? That wouldn't be an option in this case, all the attached garages are on a slab, and the basement is under the main structure of the house. (And all the services are on garage walls.)

mdshunk, I might give that a whirl. I thought about it, but I thought the clamp on the inside of the box would take away too much space on the inside of the metermain. Sometimes I have a real hard time getting my loops in as it is. :)

[iwire]

Originally posted by georgestolz:
so you pipe out of the metermain down the wall into the basement below? Yes...if you swap the metermain for a meter and swap the pipe for SE. :p

[j_erickson]

George, so where do you mount your panel(s)? I'm with Scott in my installs.

And Bob :)

[ November 27, 2005, 10:01 AM: Message edited by: j_erickson ]

[pierre]

Mdshunk

"2 screw romex connector installed backwards (locknut on the outside of the box)"

What does that do for your bending radius inside the enclosure?

[George Stolz]

George, so where do you mount your panel?[/QB]We install a metermain at the side of the garage wall, usually five feet in from the face of the garage. From the service, we run a main SER feeder up the wall, across the garage ceiling, and into the top of the panel, which is usually in a garage wall, adjoining the interior of the house.

Generally, the exterior wall of the garage is a 2x4 wall. With 4/0 AL SER, the turn is tough with just an MA in the back of the metermain. When you throw an SER connector into the mix, the connector expresses a sincere desire to rip whatever remaining concentrics are there, out of the back of the box.

With an MA serving as a bushing, the SER enters the MA at a slight downward angle, reducing some of the required turn. With the clamp, that angle has to go away if you tighten the clamp, so I wind up beating the SER with a hammer into a "sharp" 90 (as sharp a 90 as 4/0 will achieve) so that it will enter the box square enough to get the locknut and bushing onto the connector.

(Spare the lecture about 5x the radius of the cable, with all my efforts I still don't come close.)

If nothing else, I guess I can step up from a 2" to a 2.5" SER connector. That would leave nothing to rip out of the back of the box. :o

[mdshunk]

Originally posted by pierre:
Mdshunk

"2 screw romex connector installed backwards (locknut on the outside of the box)"

What does that do for your bending radius inside the enclosure? It certainly doesn't help (the bending radius). This is a troublesome area that needs some attention from the manufacturers. We do the best we can with what we have to use. Builders are reluctant to frame a garage wall with 2x6's, when not otherwise required.

[George Stolz]

...and not terribly keen on having a "bump" in the wall where I'd frame out for more room. But I'm getting to that point.

I already frame out the interior wall to allow for insulation behind the panel. What's one more bump? :)

[pierre]

So my question is:
Do we disregard the NEC until a better fitting is designed? Or, do we have the contractor or ourselves build the wall to accept the bending radius of the cable.

A novel idea is to use a different wiring method that would help us conform to the NEC....

[ November 27, 2005, 03:39 PM: Message edited by: pierre ]

[George Stolz]

I'd as soon frame out as opposed to piping it.

[mdshunk]

Originally posted by georgestolz:
I'd as soon frame out as opposed to piping it. Right. If you can't go directly into the back of the panel, you'll have an LB cover that will somehow need to be exposed in the garage. Now do we need to ask the manufacturer's to make a flush LB cover? I'm not suggesting that we disregard the NEC, but we sure could use a better fitting.

[pierre]

Of course you do have these other choices.
230.43
(1) Open wiring on insulators
(2) Type IGS cable
(3) Rigid metal conduit
(4) Intermediate metal conduit
(5) Electrical metallic tubing
(6) Electrical nonmetallic tubing (ENT)
(7) Service-entrance cables
(8) Wireways
(9) Busways
(10) Auxiliary gutters
(11) Rigid nonmetallic conduit
(12) Cablebus
(13) Type MC cable
(14) Mineral-insulated, metal-sheathed cable
(15) Flexible metal conduit not over 1.8 m (6 ft) long or liquidtight flexible metal conduit not over 1.8 m (6 ft) long between raceways, or between raceway and service equipment, with equipment bonding jumper routed with the flexible metal conduit or the liquidtight flexible metal conduit according to the provisions of 250.102(A), (B), (C), and (E)
(16) Liquidtight flexible nonmetallic conduit

[jbwhite]

Originally posted by mdshunk:
Originally posted by georgestolz:
I'd as soon frame out as opposed to piping it. Now do we need to ask the manufacturer's to make a flush LB cover?you could have the carpenter make a decorative door.

[mdshunk]

[ November 27, 2005, 05:33 PM: Message edited by: mdshunk ]

[mdshunk]

Okay, Pierre. You twisted my arm. I'm gonna start using IGS cable on the load side of the meter. :D Seriously, the goal here is to get something that will fit in a 2x4 framed wall. That is hard to attain using SE cable with the wiring methods and fitting currently available to us. Darned impossible with SER. I guess they do make 90* connectors for type MC cable. That would be a decent option.

[ November 27, 2005, 05:34 PM: Message edited by: mdshunk ]

[George Stolz]

Originally posted by pierre:
Of course you do have these other choices.
230.43They're not service conductors. :)

Do they make 1/3 CU NM? :p

[mdshunk]

Originally posted by georgestolz:
Originally posted by pierre:
Of course you do have these other choices.
230.43They're not service conductors. :)

Do they make 1/3 CU NM? :p NM's not on the list, but MC is. They certainly make MC in the gauges we'd need for a service. All kidding aside, I'm not giving it some thought for these oddball installations, since they have a 90* connector available. I'm now pondering what special bonding efforts I'd need to attend to in that case.

[jbwhite]

can a 90 deg MC connector be legally burried in a wall?

[mdshunk]

Originally posted by jbwhite:
can a 90 deg MC connector be legally burried in a wall? Hmmmm... that might throw a hitch into my grand plan. It does sort of have a removable cover. Why would you ever need to remove it, though? You can't replace the conductors in MC cable like you could do with an LB and a raceway system. There's no viable reason why that fitting would ever require service. If we we're talking Greenfield, and not MC, I'd say that it can't be buried. If that cable ever needed replaced, you'd have to open up the wall anyhow. I say it can be buried for now...

[ November 27, 2005, 07:02 PM: Message edited by: mdshunk ]

[George Stolz]

Originally posted by mdshunk:
NM's not on the list (230.43), but MC is.They're not service conductors, mdshunk. :)

[mdshunk]

Originally posted by georgestolz:
Originally posted by mdshunk:
NM's not on the list (230.43), but MC is.They're not service conductors, mdshunk. :) Most people call me Marc.

[George Stolz]

Oh, right. They're cables and raceway systems. Jeeze...No, I'm saying Pierre's list doesn't apply, there's a main breaker outside. Or are we talking in circles? :D

Nice to finally make your aquaintance, Marc. http://www.mikeholt.com/codeforum/icons/icon14.gif

[mdshunk]

I was able to determine that MC cable with (3)3/0 and one #4 does have an overall diameter of 1.600 inches. The 90* MC connector for that cable diameter (from Arlington) would stick out of the back of the meter main 2.300 inches. That would fit nicely in a 2x4 wall.

[pierre]

3/0 requires minimum of 4 inches of bending radius inside the panel as per 312.6. Selecting how one enters the enclosure is very important.

[George Stolz]

Originally posted by mdshunk:
That would fit nicely in a 2x4 wall. I imagine the 1/2" or so of OSB + Siding might throw a wrench in the works. Try it out, let me know how it goes. :D

Selecting how one enters the enclosure is very important.I need to tell that side of my brain to stop giggling, grown-up stuff is going on. :D

[jwelectric]

Originally posted by pierre:
3/0 requires minimum of 4 inches of bending radius inside the panel as per 312.6. Selecting how one enters the enclosure is very important. Would this be the bending space at terminals?

Is not the bending radius of SE cable not to exceed five times the diameter of the cable measured along the inter curve?
:)

[pierre]

When conductors enter an enclosure, you will need to pay particular attention to 312.6(A) & (B).
Also read 312.6 Deflection of Conductors.

Some of the other bending radius that you have mentioned could be for wire located ouside of enclosures, such as bending around corners.

[mdshunk]

Originally posted by pierre:
3/0 requires minimum of 4 inches of bending radius inside the panel as per 312.6. Selecting how one enters the enclosure is very important. I agree. Are you trying to indicate that an MC cable fitting exists for a certain size of MC cable that can't be used in a compliant manner? I don't think you are.

I'm just playing devil's advocate. In truth, there are three sizes of MC cable right angle fitting that will work for this O.D. size of MC. I picked the smallest in my example. I'd have to jump up a size or two to accomodate for the thickness of the sheathing and siding anyhow. That would take care of the bending radius issue handily.