"Weatherproof" and IP Ratings

[Jerramundi]

Why would an additional enclosure be installed?

I ask because I have a NEMA Type 3R xfrmr for a low voltage lighting system but as Jraef said...

...3R and 4 are considered weather resistant, although 3R is not actually required to be watertight, only that water cannot get to live components...

And when I think about your typical outdoor receptacle, it's required that the enclosure be weatherproof and the device be weather resistant.

So if 3R is only weather resistant and not weatherproof, I'm wondering if the 3R xfrmr should be contained in a truly weatherproof enclosure, only problem with that is it would likely affect cooling. The manufacturer's specs for the xfrmr explicitly state it should be in an area that allows for free flowing air.

I guess this is what happens when you actually care enough to try to back up the conventional jargon with code and certifications, lol. Pandora is not pleased I opened her box, lol.

 

[FionaZuppa]

I would call 3R's "weather resistant"
I would call 4 & 4X's "weatherproof"

NEMA Ratings Buying Guide for Type 1, 3R, 4, 4X, 12 Differences | NEMA Enclosures

NEMA is a rating system for equipment that might be exposed to liquids, rain, ice, corrosion and contaminates such as dust. Find out which one you need!

www.nemaenclosures.com

Weather Resistant for xfrmrs are for std wet environments. Extreme weather locations would call for a 4 or 4X.

And when I think about your typical outdoor receptacle, it's required that the enclosure be weatherproof and the device be weather resistant.

I may have not seen it, where in NEC does it specify that using those words? 312.2 ?

2017 NEC
Watertight. Constructed so that moisture will not enter the
enclosure under specified test conditions. (CMP-1)

Weatherproof. Constructed or protected so that exposure to
the weather will not interfere with successful operation.
(CMP-1)
Informational Note: Rainproof, raintight, or watertight equipment
can fulfill the requirements for weatherproof where varying
weather conditions other than wetness, such as snow, ice,
dust, or temperature extremes, are not a factor.

I can say almost with 100% certainty, the NEC seems to use the word "weatherproof" on the light side of "proofing", the way the word is used in NEC book suggests a NEMA 3 or better will suffice.

 

[FionaZuppa]

I think it's just an issue of mixed use of the terms.

A 'wp' rated box for wet location recept is more like a NEMA 3 vs a NEMA 4, etc.

 

[Jerramundi]

I think it's just an issue of mixed use of the terms.

A 'wp' rated box for wet location recept is more like a NEMA 3 vs a NEMA 4, etc.

It's just a little confusing because, as you stated, and based on the link provided, a NEMA 3R rating would be "Weather Resistant," and when installing Wet Locations receptacles... I install a "Weather Resistant (WR)" device in a "Weatherproof (WP)" enclosure (I'll have to get back to you on code references for those reqs).

I would think those requirements would transverse to all products installed in a Wet Location and thus a NEMA 3R xfrmr (i.e. WR) should be in a NEMA 4 enclosure (WP).

 

[Jerramundi]

I may have not seen it, where in NEC does it specify that using those words? 312.2 ?

2017 Code Language:

406.9(B)(1) Receptacles of 15 and 20 Amperes in a Wet Location.

Receptacles of 15 and 20 amperes, 125 and 250 volts installed in a wet location shall have an enclosure that is weatherproof whether or not the attachment plug cap is inserted. An outlet box hood installed for this purpose shall be listed and shall be identified as “extra-duty.” Other listed products, enclosures, or assemblies providing weatherproof protection that do not utilize an outlet box hood need not be marked “extra duty.”

Informational Note No. 1: Requirements for extra-duty outlet box hoods are found in ANSI/UL 514D–2013, Cover Plates for Flush-Mounted Wiring Devices. “Extra duty” identification and requirements are not applicable to listed receptacles, faceplates, outlet boxes, enclosures, or assemblies that are identified as either being suitable for wet locations or rated as one of the outdoor enclosure–type numbers of Table 110.28 that does not utilize an outlet box hood.

Exception: 15- and 20-ampere, 125- through 250-volt receptacles installed in a wet location and subject to routine high-pressure spray washing shall be permitted to have an enclosure that is weatherproof when the attachment plug is removed.

All 15- and 20-ampere, 125- and 250-volt nonlocking-type receptacles shall be listed and so identified as the weather-resistant type.

Informational Note No. 2: The configuration of weather-resistant receptacles covered by this requirement are identified as 5-15, 5-20, 6-15, and 6-20 in ANSI/NEMA WD 6–2012, Wiring Devices — Dimensional Specifications.

 

[bwat]

It’s rather common to see 3R enclosures outdoors if conditions are not extreme.

 

[paulengr]

NEMA does not use the terms weathertight and weatherproof. Transformers have their own rating system too that is not directly compatible with NEMA. I’ve seen some with NEMA enclosure ratings but that’s not the standard.

NEMA types 3 (which includes several lesser known or rare subtypes such as 3SX), 4, and 6 are weatherproof against many types of weather. That’s the problem here. For instance 3R has you covered for all types of moisture but it’s the only 3 subtype without a gasket against dust. NEMA really just defines tests intended to simulate specific conditions. 3R may or may not be weatherproof in your area. The receptacle standard fails to define it either. So I would say that for instance 3R would be weatherproof for general applications. At the beach it might need to be 3 or 4 and at the beach near the ocean 4X for corrosion. See....weatherproof depends on the weather.

 

[kwired]

I ask because I have a NEMA Type 3R xfrmr for a low voltage lighting system but as Jraef said...



And when I think about your typical outdoor receptacle, it's required that the enclosure be weatherproof and the device be weather resistant.

So if 3R is only weather resistant and not weatherproof, I'm wondering if the 3R xfrmr should be contained in a truly weatherproof enclosure, only problem with that is it would likely affect cooling. The manufacturer's specs for the xfrmr explicitly state it should be in an area that allows for free flowing air.

I guess this is what happens when you actually care enough to try to back up the conventional jargon with code and certifications, lol. Pandora is not pleased I opened her box, lol.

Typical outdoor receptacle cover is weather resistant "when cover is closed" "in use" covers can have cover closed while a cord is plugged into the receptacle.

 

[Jerramundi]

Typical outdoor receptacle cover is weather resistant "when cover is closed"

What are you basing this on? Your "typical outdoor receptacle cover" seems very subjective. The bubble covers I usually go with explicitly advertise themselves as "Weatherproof."

But I digress. My main question was about IP Ratings as they pertain NEC "Weather Resistant" and "Weatherproof" standards because all the products I'm researching are UL Listed but don't give a specific standard, only an IP Rating.

I only brought up the (WR) Receptacle and (WP) Enclosure scenario as an example. Like I said, I would think this standard would transverse across all installations in a wet location (i.e. WR equipment in WP enclosures), but that is just speculation.

 

[Jerramundi]

So I would say that for instance 3R would be weatherproof for general applications. At the beach it might need to be 3 or 4 and at the beach near the ocean 4X for corrosion. See....weatherproof depends on the weather.

I would have to disagree with that depending on your definition of "general application." The only documentation I've seen thus far in this thread that would support that conclusion was that presented by FionaZuppa in Post #22... contingent upon the Informational Note which states...

"...watertight equipment can fulfill the requirements for weatherproof where varying weather conditions other than wetness, such as snow, ice, dust, or temperature extremes, are not a factor."

The subsequent question would be... does "extremes" apply to "snow, ice, dust..." or just "temperature?" The logical operand "or" here seems to separate "temperature extremes" from the other categories. Thus, if snow and ice are factors, watertight cannot satisfy weatherproof requirements.

Even then, it's my understanding that 3R is not technically watertight... nor do I live in a place where snow and ice formation are not factors. Even if 3R would qualify as "Weatherproof," it's clearly one of the minimum acceptable ratings for such.

For my particular application I think I'm going to with a UL Listed NEMA 4 enclosure just to be certain... and house my 3R xfrmr's in there. I found a good distributor that has NEMA 4 enclosures for a fairly reasonable price, unlike the previously linked NEMAEnclosures.com, whose smallest NEMA 4 enclosures runs upwards of $300.00 big ones. I found a UL listed NEMA 4 for $50.00

 

[Jerramundi]

Ultimately it does boil down to the AHJ... only problem is my local municipality has a nice little liability statement in their village code that explicitly states "the electrical contractor is responsible for anything missed by the inspector."

 

[paulengr]

I would have to disagree with that depending on your definition of "general application." The only documentation I've seen thus far in this thread that would support that conclusion was that presented by FionaZuppa in Post #22... contingent upon the Informational Note which states...

"...watertight equipment can fulfill the requirements for weatherproof where varying weather conditions other than wetness, such as snow, ice, dust, or temperature extremes, are not a factor."

The subsequent question would be... does "extremes" apply to "snow, ice, dust..." or just "temperature?" The logical operand "or" here seems to separate "temperature extremes" from the other categories. Thus, if snow and ice are factors, watertight cannot satisfy weatherproof requirements.

Even then, it's my understanding that 3R is not technically watertight... nor do I live in a place where snow and ice formation are not factors. Even if 3R would qualify as "Weatherproof," it's clearly one of the minimum acceptable ratings for such.

For my particular application I think I'm going to with a UL Listed NEMA 4 enclosure just to be certain... and house my 3R xfrmr's in there. I found a good distributor that has NEMA 4 enclosures for a fairly reasonable price, unlike the previously linked NEMAEnclosures.com, whose smallest NEMA 4 enclosures runs upwards of $300.00 big ones. I found a UL listed NEMA 4 for $50.00

Watertight (NEMA 4) has problems with sweating where 3 doesn’t. Hence it is not generally as weatherproof as NEMA 3. This is getting outside of Code but the fix is installing a breather. The non-Code practice is drilling a 1/8” hole in the bottom.

 

[FionaZuppa]

Typical outdoor receptacle cover is weather resistant "when cover is closed" "in use" covers can have cover closed while a cord is plugged into the receptacle.

And oddly, the typical ones have gasket while the in-use ones do not. In my book they are all "weather resistant" and not "weatherproof".

There's not set standard for those terms thus they are used quite broadly.

 

[kwired]

What are you basing this on? Your "typical outdoor receptacle cover" seems very subjective. The bubble covers I usually go with explicitly advertise themselves as "Weatherproof."

Your covers don't add "when cover closed" to the verbiage printed on them? Most do.

Seems like they would just for legal purposes when a non electrical professional would get involved in some sort of claim - "but it says it is weatherproof"

 

[kwired]

And oddly, the typical ones have gasket while the in-use ones do not. In my book they are all "weather resistant" and not "weatherproof".

There's not set standard for those terms thus they are used quite broadly.

Bold part I can agree with. Anything outdoors or even in an indoor wet location is subject to water being inside. Especially if designed/installed that condensation can easily occur. Those gaskets and seals keep water out, but once it is in they keep it in as well.

 

[kwired]

Watertight (NEMA 4) has problems with sweating where 3 doesn’t. Hence it is not generally as weatherproof as NEMA 3. This is getting outside of Code but the fix is installing a breather. The non-Code practice is drilling a 1/8” hole in the bottom.

I install many enclosures that are rated NEMA 4 and 12, some even have instructions to convert to 3R to drill hole(s) in the bottom.

Square D panelboard cabinets (this the real panelboards not the loadcenters) in particular have one series that is rated 3R, 5 and 12- instructions included state to use as 3R to remove drain screws in the bottom wall of cabinet.

 

[Jerramundi]

Watertight (NEMA 4) has problems with sweating where 3 doesn’t. Hence it is not generally as weatherproof as NEMA 3. This is getting outside of Code but the fix is installing a breather. The non-Code practice is drilling a 1/8” hole in the bottom.

I was not aware of the "sweating" problem. I believe there is a section of code which does apply to your suggested solution (i.e. drilling a hole in the bottom). It specifies a particular size of hole but I can't recall what it is off the top of my head. Appreciate that input.

 

[rbalex]

I was surprised it took 19 responses (Post 20) before anyone mentioned Table 110.28. I will mention a few other things.

• The Table indicates the recognized uses of various enclosure "Types".
• The Types are determined by specific sets of tests.
• An enclosure marked with multiple identifications is suitable for each use indicated.
• As noted in the referred to IN No.2, "IP" ratings are meaningless in the NEC. More importantly, they are meaningless to FedOSHA.
• While an enclosure may also be marked with an IP rating, it is still meaningless in the context of the NEC,

I said over 25 years ago, attempting to introduce IEC practices to the US domestic installations would cause nothing but confusion.

 

[kwired]

I was not aware of the "sweating" problem. I believe there is a section of code which does apply to your suggested solution (i.e. drilling a hole in the bottom). It specifies a particular size of hole but I can't recall what it is off the top of my head. Appreciate that input.

There is wordage stating raceways shall be arranged to drain. I am not aware of anything telling to drill holes in bottom of enclosures, though that is an effective way of preventing accumulation of condensation.

As I have mentioned there are enclosures that come with instructions to drill holes or remove already installed plugs/screws/etc to essentially convert the enclosure to type NEMA 3R, but those still are tighter sealed than the average 3R loadcenter cabinet or similar enclosures.

 

[Steve Merrick]

In the US (and Canada?), IP ratings are meaningless, you must use UL Enclosure Type
Outside of the US, UL Enclosure Types are meaningless you must use the IP rating.

Any one enclosure may have ratings for both UL Enclosure Type and IP, but that does not mean the ratings are equivalent.
For example: if enclosure A is rated 4X and IP65, it does not mean that enclosure B rated IP65 can be used in the same location as enclosure A, in the US. Likewise enclosure C with only a 4X rating cannot be used in place of enclosure A, in France.

While I agree with you on the irrelevancy of IP ratings for enclosures, IP ratings are still highly relevant for electrical components such as terminals where the IP2X "Fingersafe" standard (IEC 60529) is widely specified and has arguably become the industry norm. NEMA has no equivalent nor does UL. But for the purposes of this thread on weatherproof enclosures, I agree that NEMA ratings and corresponding UL enclosure types are used in the US, not the IEC standard.