225.22 "Drain"...how?

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Zeno

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"225.22 Raceways on Exterior Surfaces of Buildings or
Other Structures.
Raceways on exteriors of buildings or
other structures shall be arranged to drain and shall be
raintight in wet locations." NEC 2008

I'm looking for a bit of clarification on how this code could possibly be executed.

For example, say I had a run of 2" IMC coming down through the eave that had to make a 90 degree horizontal turn to get over to the meter. Now, seems to me, this code is meant to keep possible water from making it's way inside the conduit all the way back to the meter (assuming it somehow got in through the weatherhead or some other means)...but how to drain? Would I manually drill some small holes at the 90 degree elbow (or LL/LR)? If so, the "drainage" holes would obviously have to be made before the cables were run, but then, would the holes damage the insulation?

Any help would be appreciated.

Zeno


 
In my opinion your conduit is arranged to drain, it will drain into the meter base and out the drain holes in the meter base.

Had you made a second 90 up into the bottom of the meter base the conduit would need a way to drain.
 
Use a "T" fitting instead of a "L" and install a drain(Cooper C-H ECD15) & reducer in the unused opening of the "T",a very common practice in industrial applications when draining condensate from vertical runs.
 
iwire said:
In my opinion your conduit is arranged to drain, it will drain into the meter base and out the drain holes in the meter base.
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This is good enough for me.....

For the few drops of moisture that may condense in the conduit, I don't think it's worth installing any extra fittings just to help it drain.
 
I agree with both but it doesn't read to arrange so that it will drain into the meter can:)

That approach would not get by all inspectors.

dick
 
dicklaxt said:
I agree with both but it doesn't read to arrange so that it will drain into the meter can:)

That approach would not get by all inspectors.

dick
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But it will drain into the meter can.

What will a few drops of condensation hurt?

I have seen many installations where they have created a "trap" in a raceway and it holds water. Steel raceway on a steel structure in areas with high humidity will fill up with condensation faster than you think. If you are in a location where it also freezes - these raceways full of water do freeze and split open - which I guess does take care of the drainage problem once it is split open. I always avoid making a "trap" in the raceway. I always drill "weep holes in boxes, conduit bodies, etc. if they are in a spot where water will accumulate in them. This is exactly why type 3R enclosures have drain holes in them - to drain moisture that ends up inside.
 
dicklaxt said:
Don't disagree with you at all,,,but the inspector might:)
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I am not afraid to get into debate over reality with the inspector. Outdoor raceways collect condensation. Maybe if you are in Arizona, New Mexico, Nevada, they will not collect much, but they will collect some condensation at some time. Most everywhere else it will be somewhat significant at least during certain times of the year.
 
zbang said:
And please, if you drill a drain hole in a galvanized fitting or box, put some cold-galvanizing paint around the hole. That'll put off the rust a little longer.
Click to expand...

Not necessarily a bad idea, but draining the water because you drilled the hole usually prevents even more severe problems. I often only drill 1/8 inch hole, have to be careful not to reseal the hole with the cold galvanizing.
 
dicklaxt said:
I agree with both but it doesn't read to arrange so that it will drain into the meter can:)

That approach would not get by all inspectors.

dick
Click to expand...

Weather head, 8 foot stick of conduit mounted vertical, meter can. This probably encompasses 95% of all overhead services in the United States. That arrangement will always drain down in to the meter can. Haven't ever heard of an inspector shoot it down yet.
 
Strathead said:
Weather head, 8 foot stick of conduit mounted vertical, meter can. This probably encompasses 95% of all overhead services in the United States. That arrangement will always drain down in to the meter can. Haven't ever heard of an inspector shoot it down yet.
Click to expand...

Also very good reason for the meter can to be a type 3R enclosure, with drain holes in the corners of the bottom. Those holes are not there just because of coincidence of how the bottom is made, they intentionally do not seal them up so it will drain. Has anyone ever seen a type 12 meter enclosure? If there is such a thing it will not drain without someone putting a place in for it to drain.
 
I guess this is one of those areas of the code and it's stated similiarlly again in 250.33 that these two articles do not apply when you are entering a meter can with weep holes.

Words are words and words have meaning in forming rules but are often not adhered to, in this case we have an accepted work around evidently.

dick
 
Thanx to everyone for the great ideas and responses.

iwire said:
Had you made a second 90 up intothe bottom of the meter base the conduit would need a way to drain.
Click to expand...
That ?second 90? going upward is another good question abouthow to apply this code in general.
Perhaps that would be a good time to use a T fitting or drill some small holes? Also, to drain, would anyone suggest having any slope to a horizontal run so it would drain in one direction (toward the T fitting ordrilled holes) rather than have perfectly level run?


kwired said:
...This is exactly why type 3Renclosures have drain holes in them - to drain moisture that ends upinside.
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Then, to stick with the meter example, wouldn?t any enclosure that didn?t have these holes and therefore not drain...not meet the code?


zbang said:
And please, if you drill a drainhole in a galvanized fitting or box, put some cold-galvanizing paint around thehole. That'll put off the rust a little longer.
Click to expand...
I won?t get dinged for drilling holes, though, will I? I've heard that altering any UL listed product can be opening a can of worms?


north star said:
= = =

Zeno,

...and Welcome to the Mike Holt Forum!

$ $ $
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Thank you!:D This question came up in my NEC Code class and my teacher suggested I ask it in the forums. I was lurking for several days before I decided to take the plunge. Great atmosphere here.


dicklaxt said:
I guess this is one of thoseareas of the code and it's stated similiarlly again in 250.33 that these twoarticles do not apply when you are entering a meter can with weep holes.

Words are words and words have meaning in forming rules but are often notadhered to, in this case we have an accepted work around evidently.

dick
Click to expand...

Perhaps the example I gave in the first post wasn?t thebest one?I was really just looking to understand how/when the code applied and what most people do to meet this code. If anyone has had to deal with this issue of draining and has better and more used example than the one I gave, I'd be very interested.

Zeno
 
I have seen underground installations where the transformer is uphill of the structure. Water

will collect in PVC conduit & end up coming out of the meter. The solution is to drill weep holes

at the lowest point, usually the last 90. Fill the area around the elbow with gravel to allow water

to drain away.
 
Zeno said:
I won?t get dinged for drilling holes, though, will I? I've heard that altering any UL listed product can be opening a can of worms?
Click to expand...
Any time you use your knockout punch or hole saw, you are 'altering' a product.

The listing has to do with how the item left the factory. According to UL, it is always up to the AHJ to decide if your installation negatively impacts the 'integrity' of the listing.
 
Replies embedded in the quote in red:

Zeno said:
Thanx to everyone for the great ideas and responses.


That ?second 90? going upward is another good question abouthow to apply this code in general.
Perhaps that would be a good time to use a T fitting or drill some small holes? Also, to drain, would anyone suggest having any slope to a horizontal run so it would drain in one direction (toward the T fitting ordrilled holes) rather than have perfectly level run?

I don't think it is necessary to drain every bit of water out of the raceway, even a minor slope will likely retain a little water at times, but just make sure it can not completely fill and stand there, especially if in EMT which will rust faster, or if in a location that freezes.

Then, to stick with the meter example, wouldn?t any enclosure that didn?t have these holes and therefore not drain...not meet the code?

IMO, yes. Even a Type 12 enclosure with raceways entering from above can be found with water inside sometimes, where is it supposed to go?

I won?t get dinged for drilling holes, though, will I? I've heard that altering any UL listed product can be opening a can of worms?

I have seen enough damaged equipment from sealed raceways/enclosures that I think it is worthwhile to drill holes vs let an enclosure fill with water and destroy devices within it, or have a raceway with trapped water freeze and split open.


Thank you!:D This question came up in my NEC Code class and my teacher suggested I ask it in the forums. I was lurking for several days before I decided to take the plunge. Great atmosphere here.

​present these replies to the instructor and rest of the class.


Perhaps the example I gave in the first post wasn?t thebest one?I was really just looking to understand how/when the code applied and what most people do to meet this code. If anyone has had to deal with this issue of draining and has better and more used example than the one I gave, I'd be very interested.

Zeno
Click to expand...
 
Had a job where the transformer was in a UG vault up hill from the house. Power company required a underground vault downhill so water would not flow into the service. I drill holes in exterior boxes, including handy boxes so water can drain. Have opened up lots of 'waterproof' boxes filled with water.
In regard to service risers, have assumed that heat from the wires and the sun would take care of condensation, but I live in CA.
 
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