Drainage holes

[Steelhead]

Is it permissible to drill some small holes, (1/8" or so), in the bottom of an outdoor rated enclosure to allow any moisture that may accumulate, to drain out?

 

[Jraef]

Not just permissible, it's REQUIRED if the enclosure doesn't already have provisions for that. Typically if the enclosure is rated as type 3R, that is part of the listing, so the mfr would have accounted for providing a "weep hole" or a gap of some sort on the bottom of the box. But sometimes when installing conduit, I have seen guys use the weep hole as a pilot hole for their hole saw! In that case, you must then drill another one. If a box is Type 4 / 4X and there is no hole, then if you only needed 3R, you can drill the hole, but if you must maintain the type 4 rating, you have to use a fitting called a "Drain" accessory that threads into the bottom.

 

[Steelhead]

Thanks for the info!

 

[Knuckle Dragger]

I am firm believer in using or drilling weep holes on exterior or wet location boxes.

I have never seen those vent drains before very cool.:thumbsup:

 

[Ozymandias]

Just to add to Jraef info, I've work in industrial settings where we run ridgid pipe into a T condulet and enter the bottom of an exterior enclosure, the bottom of that T has the drain and we only enter the box once at the bottom, never at the top or side. My employer found out the hard way.

 

[Strathead]

Not just permissible, it's REQUIRED if the enclosure doesn't already have provisions for that. Typically if the enclosure is rated as type 3R, that is part of the listing, so the mfr would have accounted for providing a "weep hole" or a gap of some sort on the bottom of the box. But sometimes when installing conduit, I have seen guys use the weep hole as a pilot hole for their hole saw! In that case, you must then drill another one. If a box is Type 4 / 4X and there is no hole, then if you only needed 3R, you can drill the hole, but if you must maintain the type 4 rating, you have to use a fitting called a "Drain" accessory that threads into the bottom.
View attachment 18791

NEMA three also has no weep hole. A typical Square D exterior panel carries a 3R and a 3 rating. The instructions (those pesky pieces of paper that few outside of people who care enough to join sites like Mike Holt read) says to remove the screws in the bottom of the panel for N3R and leave them in for N3.