312.2, PVC, and a Meter Socket

Status
Not open for further replies.

George Stolz

Moderator
Staff member
Location
Windsor, CO NEC: 2017
Occupation
Service Manager
WMM4UR1.jpg


If a PVC MA were to enter into the sidewall of the upper portion of this meter module, would it need a rubber washer on the MA?

Do you routinely install rubber washers on PVC MAs in your area?
 

Buck Parrish

Senior Member
Location
NC & IN
Yes, if it your hole is high up. Not a factory hole.
This comes in handy if you want to make all the tops of the panels the same hight.
But you have to watch your bending space.
I carry some on the truck. Mostly just 2" ones.

I have used that meter socket in the picture it has 2 ecentric knockouts on the bottom and two ecentric knockouts on the right side near the bottom
 
Last edited:

George Stolz

Moderator
Staff member
Location
Windsor, CO NEC: 2017
Occupation
Service Manager
This one has six concentrics in the very bottom, six in the backside below the bottom meter. I don't see where factory holes enter into the equation though.

If a hole for a 1.25" PVC is factory provided or field drilled in the side of that can next to the top meter, does the PVC MA need a rubber washer? Are rubber washers readily available?
 

Cow

Senior Member
Location
Eastern Oregon
Occupation
Electrician
My rule of thumb is any time I enter above terminations/live bus, I'll use a sealing locknut or myers hub. Can't say I've ever used a rubber washer, wouldn't even know who made 'em?
 

quogueelectric

Senior Member
Location
new york
Service equipment by me is strictly forbidded to have field installed holes in it only factory supplied kos are acceptable here VERY! strictly enforced.
 

macmikeman

Senior Member
Nothing to say about where holes are knocked out, but rubber o rings can be found in most hardware stores. Properly sized they will do the job the op is wondering about as far as keeping wet out. Getting past inspector would be another thing.
 

M. D.

Senior Member
Keep in mind the rubber washer is not a listed fitting,.. it will work but we all know there are some inspectors who could find fault.
 

Teaspoon

Senior Member
Location
Camden,Tn.
Keep in mind the rubber washer is not a listed fitting,.. it will work but we all know there are some inspectors who could find fault.

The Inspector that inspects most of my jobs,likes for me to put a little dab of clear silicon on the contact surface of the male adapter when you tighten the lock-nut it pushes out around the edges. The excess can easily be wiped off leaving a neat water tight seal.
 

iwire

Moderator
Staff member
Location
Massachusetts
WMM4UR1.jpg


If a PVC MA were to enter into the sidewall of the upper portion of this meter module, would it need a rubber washer on the MA?

In my opinion yes, without a doubt if you enter higher than the live parts you must do something to seal that entry.

Do you routinely install rubber washers on PVC MAs in your area?

I would go to almost any length to avoid making a side entry into that gear. Where I have had to enter the side of gear I have used sealing locknuts.


Keep in mind the rubber washer is not a listed fitting,.. it will work but we all know there are some inspectors who could find fault.

I am pretty sure Carlon sells a listed 'washer' for the MAs just like the one that comes with many liquid-tight connectors.:)
 

Smart $

Esteemed Member
Location
Ohio
I am pretty sure Carlon sells a listed 'washer' for the MAs just like the one that comes with many liquid-tight connectors.:)
The very first item in linked Carlon catalog section, but it doesn't say they're listed...

http://www.carlonsales.com/techinfo/brochures/conduit/Conduit_Bodies_Brochure.pdf

EDIT: If you are concerned about listing, use these...

http://www.tnb.com/ps/fulltilt/index...ck=Y&part=5303

They are listed under file E13938. General listing requirements is QCRV: Outlet Bushings and Fittings, where in part it says this...

Sealing Gaskets (Washers) — Sealing gaskets are intended for use with threaded rigid metal conduit and intermediate metal conduit with one sealing gasket on the outside and an ordinary locknut or sealing locknut on the opposite side of the enclosure for wet locations or liquid-tight applications. Sealing gaskets may also be used with Listed wet location or liquid-tight fittings where so marked on the fitting carton.
 
Last edited:

George Stolz

Moderator
Staff member
Location
Windsor, CO NEC: 2017
Occupation
Service Manager
Thanks for all the replies. :cool:

I hadn't run into this application before, didn't really think about it. It makes sense, is a good idea, but the inspector was focused around the "fittings listed for a wet location" aspect of the section. I was thinking to myself, "Aren't all PVC MAs listed for use in a wet location? :-? "

I didn't dispute it, I'll be correcting it on Monday morning. I had a taxing day yesterday, so just getting the service replaced and back online was good enough for me, for the weekend. He was willing to sign it off in good faith, but I know he will check on it Monday.

I'm replacing old FPE services and panels in an apartment project. Each has it's own little issues; this one, the 3" PVC conduit feeding the old service was directly behind a phone pedestal. I didn't think much of it, until I realized that the ped would occupy half of my tap box, I had to heat and offset it. There is a landscaper somewhere that insists on planting an itchy sawgrass right in front of every service - can't wait to find that guy.

Then, it turned out that the 3" pipe wasn't a 3" pipe like all the rest of them, it was a 2.5" - and I was already knocked out for 3". Of course, the closest supply house was out of reducing washers.

Did you know Home Depot only stocks up to 2"? :)

Third stop, they had them, but by that point my blood pressure was up imagining the tenants' children running all over the neighborhood with anything I figured wasn't likely to be stolen. Nothing was, fortunately, but the lost time threw me off for the rest of the day. My tape measure kept lying to me, things were winding up slightly crooked, and I was getting increasingly frustrated.

I replaced the old surface-run feeders that were hanging off the building, since they were directed to places that wouldn't enter very well, and the conductors were likely too short anyway. It looks much better, but it didn't wind up perfect.

So, by the time the inspector showed up (right at 3:00pm, as I requested and am normally ready for) I was not ready, and had screwed this up as well, to boot!

Tomorrow is a new day. :)
 

mcclary's electrical

Senior Member
Location
VA
It's never happened to me but i've seen guys get turned down on "bending radius" for coming into the side of a panel like that. If you come in the side,,,it's easy for the inspector to see it and check bending radius.
 

George Stolz

Moderator
Staff member
Location
Windsor, CO NEC: 2017
Occupation
Service Manager
Could you have punched a 2.5" hole in a 4/11 cover. and bolted it in place ? Instead of useing reducing washers.
If I had the right hole saw. They didn't have that in stock either. :roll:

Edit: Actually, the Siemens tap box comes with gasketed blanks bolted to the bottom that I have to remove before I can knock it out. I had looked for the hole saw to drill that.

I would have opted (if possible ;)) for a 3" MA (or box adapter w/coupling) and a 3"?2.5" reducer bushing.
Why?

It's never happened to me but i've seen guys get turned down on "bending radius" for coming into the side of a panel like that. If you come in the side,,,it's easy for the inspector to see it and check bending radius.
It's easy to comply, too. The upper area of the can is 13" wide, and the lower is more than the 2" I'd need for a #3 CU THWN conductor.
 
Status
Not open for further replies.
Top