Penetrating the top of a outdoor NEMA 3R Gutter/Through?

[klaatu]

Take a look at this outdoor install picture I found.
Is it permissible to penetrate the top of the NEMA 3R gutter as shown? It looks like the conduit Terminal Adapters might have a gasket. I see a similar gasket with the large conduit penetrating the side of the panel to the left.

Just seems to me that the 3R rating is undone if conduit penetrates the top.

If this is permissible, can it also be done with PVC? I have searched and can't find any reference to a gasket for a PVC terminal adapter

I commonly see side penetrations with PVC terminal adapters, with no gasket.

 

[electrofelon]

Take a look at this outdoor install picture I found.
Is it permissible to penetrate the top of the NEMA 3R gutter as shown? It looks like the conduit Terminal Adapters might have a gasket. I see a similar gasket with the large conduit penetrating the side of the panel to the left.

Just seems to me that the 3R rating is undone if conduit penetrates the top.

If this is permissible, can it also be done with PVC? I have searched and can't find any reference to a gasket for a PVC terminal adapter

I commonly see side penetrations with PVC terminal adapters, with no gasket.

View attachment 2565590

Interestingly, there is no guidance in article 376 on entering NEMA 3R wireways. All that is stated, under uses permitted is: "In wet locations where wireways are listed for the purpose." I have not investigated whether any listing documents or instructions provide such requirements. I guess it is arguable that a wet location fitting is required by the raceway article.

 

[rambojoe]

Take a look at this outdoor install picture I found.
Is it permissible to penetrate the top of the NEMA 3R gutter as shown? It looks like the conduit Terminal Adapters might have a gasket. I see a similar gasket with the large conduit penetrating the side of the panel to the left.

Just seems to me that the 3R rating is undone if conduit penetrates the top.

If this is permissible, can it also be done with PVC? I have searched and can't find any reference to a gasket for a PVC terminal adapter

I commonly see side penetrations with PVC terminal adapters, with no gasket.

View attachment 2565590

You just "found" this?

 

[klaatu]

I captured the image from a video on youtube. Nothing interesting about the video but the outdoor gutter caught my attention.

I did find this gasket, which it claims is for Metallic and non-metallic conduit.... But it is just an o-ring to my eyes.

Flat Sealing Washer | Wholesale Electric Supply

Flat Sealing Washer; Type Flat Round; Fastener Size 1 Inch; Material Neoprene

www.netwes.com

I have an installation where a wide gutter would really clean things up...but it would be best with top penetrations....hence my interest.

 

[electrofelon]

I captured the image from a video on youtube. Nothing interesting about the video but the outdoor gutter caught my attention.

I did find this gasket, which it claims is for Metallic and non-metallic conduit.... But it is just an o-ring to my eyes.

Flat Sealing Washer | Wholesale Electric Supply

Flat Sealing Washer; Type Flat Round; Fastener Size 1 Inch; Material Neoprene

www.netwes.com

I have an installation where a wide gutter would really clean things up...but it would be best with top penetrations....hence my interest.

Those are for PVC only I believe. Without getting into the nuances of what code section if any requires weather tight entry and assuming it does, then your choices are the following:
1. PVC with one of those o-rings
2. Rain tight EMT connector
3. Rigid into a Myers hub
4. Rigid with a sealing lock nut

For that application I would likely just use a rain type EMT connector. They don't actually work but it meets the code requirement and I don't see an issue with a few drips in there anyway.

 

[klaatu]

1. PVC with one of those o-rings
2. Rain tight EMT connector
3. Rigid into a Myers hub
4. Rigid with a sealing lock nut

How about PVC T/A with sealing lock nut:

Its the same as using an o-ring , just on the inside

 

[electrofelon]

How about PVC T/A with sealing lock nut:

Its the same as using an o-ring , just on the inside

That's one of those stupid listing things. Technically sealing lock nuts are only for use with rigid. I bet most inspectors wouldn't know or care however.

 

[LarryFine]

I can see it sealing against the box, but does the gasket deform enough to seal the thread itself?

 

[klaatu]

Technically sealing lock nuts are only for use with rigid. I bet most inspectors wouldn't know or care however.

Is there any NEC code that would prevent use with PVC? On the flip side, is there any NEC code that allows use to keep water out with metal conduit or otherwise?

 

[yesterlectric]

I do not believe the penetrations into the top of the enclosure that appear to be using raintight EMT connectors violate the NEC. For a wireway, I wouldn't be concerned about it. What I would be concerned with however is making sure there is proper sealing in the conduits because the NEMA 3R enclosure is more likely to pick up moisture and it looks like you have some control equipment that may be more sensitive. Despite NEC rules, I would be concerned about this if it were penetrated into the top of a control cabinet or even something with uninsulated live parts inside. That just comes from seeing things happen though, and if I were an inspector it may be something I would have to allow regardless.

To electrofelon's comment on whether a minimum of NEMA 3R is required. I say it should be used and arguably is required. I however once observed something that caused me to need to look into it and I couldn't say definitively that it was required. Here's the reason one could argue over it:
- 110.28 is what requires you use certain NEMA enclosure ratings in certain locations but as written it's not really applicable to wireways just used for pullboxes.
- 314.15 and 376.10 require wireways if installed in wet locations to be listed for use in wet locations. You likely won't find if you looked into it that a NEMA 1 enclosure for example is listed for wet locations.

 

[Ryancbell121]

Those are for PVC only I believe. Without getting into the nuances of what code section if any requires weather tight entry and assuming it does, then your choices are the following:
1. PVC with one of those o-rings
2. Rain tight EMT connector
3. Rigid into a Myers hub
4. Rigid with a sealing lock nut

For that application I would likely just use a rain type EMT connector. They don't actually work but it meets the code requirement and I don't see an issue with a few drips in there anyway.

Can you do Myers hub to PVC Connector to PVC?

 

[electrofelon]

Can you do Myers hub to PVC Connector to PVC?

If you are being real nit-picky then no, Myers hub are listed for RGS only (I put PVC TA's in them all the time and never heard of anybody being called on it though). The officially correct way to go from a hub to PVC would be a rigid nipple and then an FA.

 

[Ryancbell121]

If you are being real nit-picky then no, Myers hub are listed for RGS only (I put PVC TA's in them all the time and never heard of anybody being called on it though). The officially correct way to go from a hub to PVC would be a rigid nipple and then an FA.

I want to use the top section of a 3r Service disconnect. I think I should ask the inspector what he will want.

 

[garbo]

Take a look at this outdoor install picture I found.
Is it permissible to penetrate the top of the NEMA 3R gutter as shown? It looks like the conduit Terminal Adapters might have a gasket. I see a similar gasket with the large conduit penetrating the side of the panel to the left.

Just seems to me that the 3R rating is undone if conduit penetrates the top.

If this is permissible, can it also be done with PVC? I have searched and can't find any reference to a gasket for a PVC terminal adapter

I commonly see side penetrations with PVC terminal adapters, with no gasket.

View attachment 2565590

I found the best way to enter such enclosures to prevent water intrusion is to use a heavy wall ( rigid ) conduit from above safety switch or starter to enter the top with a sealing locknut on outside of enclosure and always use a knockout ( always purchased the type that split the KO ). Saw way too many over sized holes caused by somebody using a hole saw. At locations that used high pressure nightly wash downs some water always seemed to find a way into a NEMA 4 enclosure so would drill two 1/8" drain holes at an angle towards wall.

 

[don_resqcapt19]

I found the best way to enter such enclosures to prevent water intrusion is to use a heavy wall ( rigid ) conduit from above safety switch or starter to enter the top with a sealing locknut on outside of enclosure and always use a knockout ( always purchased the type that split the KO ). Saw way too many over sized holes caused by somebody using a hole saw. At locations that used high pressure nightly wash downs some water always seemed to find a way into a NEMA 4 enclosure so would drill two 1/8" drain holes at an angle towards wall.

But make sure there are no couplings in the vertical run of conduit above the equipment as the conduit couplings have straight thread and will let water into the conduit.

 

[electrofelon]

In my experience, sealing locknuts dont work and are more just a formality to meet a code requirement. The problem with them is they just are not typically large enough to cover and seal the hole, when you consider that KO's are oversized to some degree and the conduit will typically get pushed to one side of the KO. Same thing often happens with RT EMT connectors.

 

[jap]

What type of 3r equipment are you guys installing that have KO's in the top of them?

JAP>

 

[electrofelon]

What type of 3r equipment are you guys installing that have KO's in the top of them?

JAP>

I was using "KO" to refer to the hole, whether it be field or factory made. Sorry for the confusion.

 

[garbo]

But make sure there are no couplings in the vertical run of conduit above the equipment as the conduit couplings have straight thread and will let water into the conduit.

We used to install neverseeze to threads of galvanized rigid conduit and no ox paste on Aluminum rigid conduit threads in wet or damp locations. Back in the 1970's we had a pit that stored 75,000 #'s of rock salt. They made a brine solution to provide a spray for ammonia refrigerant coils to prevent ice build up and if you did not place something on threads of rigid conduit threads would gall or corrode sometimes making it next to impossible to unscrew .

 

[garbo]

In my experience, sealing locknuts dont work and are more just a formality to meet a code requirement. The problem with them is they just are not typically large enough to cover and seal the hole, when you consider that KO's are oversized to some degree and the conduit will typically get pushed to one side of the KO. Same thing often happens with RT EMT connectors.

For 1/2 & 3/4" KO'S in wet locations entering NEMA 3 R enclosures I have used a unibits but not drilled thru say the final taper on a 7/8" unibits so I could thread the conduit into the enclosure while still using a sealing locknut. We had lazy contractors only use cheapest hole saws to make 3/4" KO'S in top of indoor panels and after a quality steel EMT connector is installed could see daylight thru every hole. We have all seen water from a sprinkler, roof leak or old drain line spray water down on top of indoor panels. Had a outdoor VFD short out due to oversized KO and water dripped onto the 665 VOLT DC buss.