EXP Switch Outdoors

Status
Not open for further replies.

don_resqcapt19

Moderator
Staff member
Location
Illinois
Occupation
retired electrician
It only has NEMA 7 and 9 ratings...neither are suitable for use outside. You need one that also has a NEMA 4 rating.
Don
 

epillow

Member
If I am interpreting 502.115 (A2) correctly, then my switchbox only needs to be NEMA4 and not explosion-proof. Would this be correct? As I said, it will be used to isolate the control circuit for servicing the unit.
 

don_resqcapt19

Moderator
Staff member
Location
Illinois
Occupation
retired electrician
Explosion proof equipment is never required for Class 2 installations. Yes, under those conditions any enclosure that will minimize the entrance of dust and prevent the escape of sparks is suitable.
Don
 

coulter

Senior Member
I don't know much about C2.

I have not looked at this for a few years (8 maybe). As noted, most all C1D1 switches have milled mating surfaces and if outside, will rot the guts in a short time. I can personally verify that's true.

About 10 years ago, Appleton came out with a C1D1 box with an O-ring around the mating surface. They also made a C1D1 in fiberglass - also with an o-ring. They both worked well. Disclaimer: I only have a couple of years of anecdotal data.

Look at current catalogs. I suspect these or better are on the market

carl
 

rbalex

Moderator
Staff member
Location
Mission Viejo, CA
Occupation
Professional Electrical Engineer
While Explosionproof enclosures (NEMA 7) are not mandated in Class II locations, Dust-Ignitionproof (NEMA 9) may be, depending on the application;e.g., Section 501.115(A)(1). Both techniques are defined and described in Sections 500.2 and 500.7.

Of the more common enclosure Types NEMA 4 is not marked "Dusttight," NEMA 3 may be. From NEMA 250, Enclosures for Electrical Equipment (1000Volts Maximum):
4.2 SUPPLEMENTAL MARKINGS
Enclosures may be additionally marked with the following supplemental markings. These are relative terms for reference purposes only and do not imply enclosure capabilities.
Raintight - A Type 3, 3S, 4 ,4X, 6, or 6P enclosure maybe marked "Raintight".
Rainproof - A Type 3R enclosure may be marked "Rainproof".
Watertight - A Type 4,4X, 6, or 6P enclosure may be marked "watertight".
Corrosion Resistant- A Type 4X or 6P enclosure may be marked "Corrosion Resistant".
Driptight - A Type 2, 5, 12, 12K, or 13 enclosure may be marked "Driptight".
Dusttight - A Type 3,3S, 5,12 ,12K, or 13 enclosure may be marked "Dusttight".
An enclosure may have multiple “Type” markings and is suitable for use in the all applications for which it is marked.
 
epillow said:
Can a Haz Location switch be installed outdoors? In particular I'm looking at a Killark XS-3C, CL1/2 Div1/2. The application would be to disconnect the control to a sequencer panel for a dust collector located on the roof of a building. Here's a link to the XS-3C (Last Page)
http://www.hubbell-canada.com/wiring/killark/PDF05/6SecC/C28-C38.pdf

All equipment listed for Class I, Division 1 and 2 are suitable for outdoor installation.
 

don_resqcapt19

Moderator
Staff member
Location
Illinois
Occupation
retired electrician
Laszlo,
All equipment listed for Class I, Division 1 and 2 are suitable for outdoor installation.
Where does it say that? A quick check of Crouse-Hinds equipment shows a number of items that have only NEMA 7 & 9 ratings while other items have 3, 7 & 9 or 4, 7 & 9. If it does not have a NEMA rating for wet locations it can't be used in wet locations.
Don
 
don_resqcapt19 said:
Laszlo,

Where does it say that? A quick check of Crouse-Hinds equipment shows a number of items that have only NEMA 7 & 9 ratings while other items have 3, 7 & 9 or 4, 7 & 9. If it does not have a NEMA rating for wet locations it can't be used in wet locations.
Don

Don,

Would you please cite some examples?
 
epillow said:
Can a Haz Location switch be installed outdoors? In particular I'm looking at a Killark XS-3C, CL1/2 Div1/2. The application would be to disconnect the control to a sequencer panel for a dust collector located on the roof of a building. Here's a link to the XS-3C (Last Page)
http://www.hubbell-canada.com/wiring/killark/PDF05/6SecC/C28-C38.pdf

The catalog reads:

[FONT=AQKKSC+HelveticaLTStd-Light]
"Installations at petroleum refineries, chemical and petrochemical plants
and other processing or storage facilities where similar hazards exist."

If it's not suitable for outdoor installations then somebody please show me and indoor petroleum refinery.:D
[/FONT]
 

don_resqcapt19

Moderator
Staff member
Location
Illinois
Occupation
retired electrician
Laszlo,
A lot of the explosion proof enclosures with a ground surface between the cover and the enclosure body are not suitable for use in wet locations. Similar products that are suitable often have a grove ground into one of the surfaces and a rubber "O" ring type material installed in the grove. This provides the water tight function and the ground surface provides the explosion proof seal.
Don
 

rbalex

Moderator
Staff member
Location
Mission Viejo, CA
Occupation
Professional Electrical Engineer
There is a fair amount of caveat emptor with hazardous location vendors. It hasn’t happened in a while, but there was a time a major manufacture claimed their hazardous location equipment was “UL compliant.” What they meant was their in-house tests indicated the equipment passed UL tests; however, the equipment still wasn’t actually listed. While it may have been misleading, it didn’t meet the standard of false advertisement; especially since the NEC only required “approved” equipment rather than “listed/labeled” at the time.

One of my former employers was a major player in getting the manufacture to “clarify” its literature.

While you may believe the vendor literature implies a certain level of performance, it is you job as a professional to confirm it.

The literature is usually more accurate today; however products that are only marked as Type 7 or 9 have not been tested to “outdoor” standards. From NEMA 250-2003:

Section 1
GENERAL
1.1 SCOPE
This standard covers enclosures for electrical equipment rated not more than 1000 Volts and intended to be installed and used as follows:

a. Non-hazardous locations
1. Enclosures for indoor locations, Types 1, 2, 5, 12, 12K, and 13; and
2. Enclosures for indoor or outdoor locations, Types 3, 3R, 3S, 4, 4X, 6, and 6P.

b. Hazardous locations
1. Enclosures for indoor locations, Types 7 and 9;
2. Enclosures for indoor or outdoor locations, Type 8; and
3. Enclosures for mining applications, Type 10.
At one time, NEMA 250 and UL 50 were virtually the same document. That is no longer the case and UL 50 has become NMX-J-235/1–ANCE-2007◊CSA C22.2 NO. 94.1-07◊UL 50, which is NAFTA rather than NEMA aligned.

In any case, an enclosure must also be marked Type 3, 3R, 3S, 4, 4X, 6, or 6P to be recognized for outdoor use. This does not necessarily mean “listed” unless the Code also specifies it.
 
don_resqcapt19 said:
Laszlo,
A lot of the explosion proof enclosures with a ground surface between the cover and the enclosure body are not suitable for use in wet locations. Similar products that are suitable often have a grove ground into one of the surfaces and a rubber "O" ring type material installed in the grove. This provides the water tight function and the ground surface provides the explosion proof seal.
Don

That is just one way, but not the only way.
 
iwire said:

Bob,

Thanks, I do have a copy of the original NEMA document and I was aware that 7 & 9 only addresses the suitability for the hazardous area, nothing else.

However, since most hazardous locations are outdoors and the approval process being so costly it would be not to smart building them for indoor use only. In the C-H book, on a quick glance, I've found all equipment is listed both XP AND outdoor use. Somebody claimed there is some that is just 7&9 and I have no dispute with the fact that it is possible. It would be just enormously stupid.:rolleyes:
 
rbalex said:
There is a fair amount of caveat emptor with hazardous location vendors. It hasn’t happened in a while, but there was a time a major manufacture claimed their hazardous location equipment was “UL compliant.” What they meant was their in-house tests indicated the equipment passed UL tests; however, the equipment still wasn’t actually listed. While it may have been misleading, it didn’t meet the standard of false advertisement; especially since the NEC only required “approved” equipment rather than “listed/labeled” at the time.

Run into this all the time. The most griveous issue was when a manufacturer used a listed enclosure, installed switching components inside drilled machnical shaft bushings in the enclosure wall and did not REMOVE the original enclosure manufacturers UL labeling.:mad:
 

iwire

Moderator
Staff member
Location
Massachusetts
weressl said:
Bob,

Thanks, I do have a copy of the original NEMA document and I was aware that 7 & 9 only addresses the suitability for the hazardous area, nothing else.


So the fact that UL says 7 & 9 are for indoor use means nothing.

They just forgot to write outdoors as well?
 
iwire said:
So the fact that UL says 7 & 9 are for indoor use means nothing.

They just forgot to write outdoors as well?

Nope, it is just stupid that they require outdoor compliance separately. They could just as have written the standard for hazardous, outdoor locations.

As I pointed out earlier the vast majority of Hazardous areas are located outdoors.
 
Status
Not open for further replies.
Top