drilling drain holes in LB fitting

[alfredeneuman]

Ooooops

I owe everybody a big apology. My main computer took a dump last week
The computer I'm using is loaded with the Draft copy of the 2014 NEC, which is released prior to the final release, and although it's clearly marked as a draft, I failed to remember that fact.

 

[pstnbly]

I had a job once where the utility pole was about 10' above the building on a hill. The underground service ran down the hill up the wall and into the meter pan. Service entrance through the back of the pan into the breaker panel. No one could figure out the moisture problem in the house until the electrician opened the breaker panel.

Water was pouring into the panel and down the inside of the wall. The electrician had me dig up the foundation down to the footing drain. He drilled a hole in the sweep that we tied to the footing drain, problem solved. The best part was watching him drill the hole in the live service.

 

[mm08822]

Are you using the NEC Handbook? The handbook is just the opinion of the author(s).

I have nec at work and hb at home. Pics from hb.

The hb is not just opinions, but code too.....
black text is the published code verbatim.
blue text if/when appears in hb is unofficial supplemental explanation/illustrations.

Yellow and grey highlights are just identifying code change from one edition to the next.

I was referencing black "code" text only.

 

[mm08822]

Ooooops

I owe everybody a big apology. My main computer took a dump last week
The computer I'm using is loaded with the Draft copy of the 2014 NEC, which is released prior to the final release, and although it's clearly marked as a draft, I failed to remember that fact.

Np, I was suspicious about the "rop" references but couldn't find any reference to it on nfpa website.
I was more concerned that you were referencing some random website's interpretation.

 

[mm08822]

Sounds like a good place for ground water to enter the pipe to me anyway.

Yeah, that's where i was heading with my basement/sump pump analogy. When the pump stops running, hydrostatic pressure builds and fills the conduit as water table rises above the hole.

 

[mm08822]

I had a job once where the utility pole was about 10' above the building on a hill. The underground service ran down the hill up the wall and into the meter pan. Service entrance through the back of the pan into the breaker panel. No one could figure out the moisture problem in the house until the electrician opened the breaker panel.

Water was pouring into the panel and down the inside of the wall. The electrician had me dig up the foundation down to the footing drain. He drilled a hole in the sweep that we tied to the footing drain, problem solved. The best part was watching him drill the hole in the live service.

I drive by a similar situation on the way to work that is only a few years old. I'm waiting for the meter to start spilling over as the conduit up the pole is open at top.

 

[mm08822]

Never drilled an LB, but usually drill 1 or 2 (1/8") to (3/16") holes in cast bell boxes. Its humid in the south!

CT

I try to put penetrox or antisize in the screw holes / plugs when possible, but pia as it sometimes turns as simple job into very messy. Grey ok, white boxes real pia.

I also try to clear silicone over the threaded studs of spotlight arms and top half of gasket perimeter as that usually compresses/rots pretty quickly. Talk about 2x'ing the labor!

 

[ard]

Article 314.15 now gives the green light to a field modification, so I don't think mfr instructions matter so much.

I had a job once where the utility pole was about 10' above the building on a hill. The underground service ran down the hill up the wall and into the meter pan. Service entrance through the back of the pan into the breaker panel. No one could figure out the moisture problem in the house until the electrician opened the breaker panel.

Water was pouring into the panel and down the inside of the wall. The electrician had me dig up the foundation down to the footing drain. He drilled a hole in the sweep that we tied to the footing drain, problem solved. The best part was watching him drill the hole in the live service.

When I installed my service here, the street is 20 feet above the panel.

3" conduit comes down to the home, then 15 feet from the house I put in a 90 and swept it up to the surface- that conduit ends there. Second piece of conduit from there, back down to the bottom of the trench, 90- then over to the foundation foot, a 90 and up into the concrete wall. Concrete outdoor E box covers the two conduits. Importantly this box is well below the level of the box in the building. Service was pulled down,loops up into this 'air gap' then continues into the main panel.

Edit: I can't take credit- the PoCo engineer told me 'do it this way' when he did the site inspection for the 400A service.

 

[mm08822]

When I installed my service here, the street is 20 feet above the panel.

3" conduit comes down to the home, then 15 feet from the house I put in a 90 and swept it up to the surface- that conduit ends there. Second piece of conduit from there, back down to the bottom of the trench, 90- then over to the foundation foot, a 90 and up into the concrete wall. Concrete outdoor E box covers the two conduits. Importantly this box is well below the level of the box in the building. Service was pulled down,loops up into this 'air gap' then continues into the main panel.

That works. Nothing like otherwise being on the low side of a giant manometer!

 

[ard]

Actually this thread would be super helpful if it moved into "WHEN is it appropriate or useful to drain or release moisture from an LB or box?"

I've had lots of perfectly dry conduit/exterior boxes in my life.... and one or two that showed corrosion/moisture in them. Wish I know when/how to predict issues.....