Class I Div. II, Need help w/ switch. Thanks.

[brantmacga]

Just finished remodeling an old general contractors facility into a
commercial paint contractors facility. The rear of the building has a
large shop that we were told would be used for storing equipment and
tools. A separate structure was to be constructed for spray booths
and storage. Got called back friday; contractor has sold old facility and
is using the rear of the shop to store flammable liquids. Now the
question: I determined this to be a class I div. II location. It has 4' high
block walls separating the materials. About 10" inside the outermost
block wall is a single pole switch controlling an 8' flourescent strip light
above, which was installed to light a loading door. Shop manager tells
me they get random ohsa checks and needs the switch moved because
of the flammable liquids. it is mounted in a 4" square w/ raised cover, fed
by MC from the light. From what i read, i think i'm safe w/ the MC. Do
I simply need to move the switch to the outer edge of the wall, and do
I need to install a seal or special approved class fitting? What about the
light overhead? Do I need to find out the igniting temperature of the liquids
and make sure the light meets the 80% rule? Its just a big open shop,
do all lights need to meet the temp requirement or just the one directly
overhead? Sorry, i just haven't done much hazardous work. Thanks for
any help you can provide!

 

[boater bill]

My first question is to make sure the area is indeed a Cl1, Div 2 area. Usually a consultant or insurance company does the audit.

They can find and evaluate things like floor drains that will accumulate fumes.

hope this helps

 

[MOISES]

This would be considered a hazardous location only if containers are opened in this area causing fume exposure . If this is the case , then the switch must be raised above 24 inches and if the feed for the switch is coming up from underground , than provide a seal off .The MC is O.K. only if the switch gets raised to 48" but I would recommend rigid conduit for this environment either way . And no , the lights do not have to meet this class if the building is opened and ventilated . Remember , only if this area is exposed to fumes , it would be considered hazardous.

 

[rbalex]

? I determined this to be a class I div. II location?

My first question when I read the OP was, ?why?? From what you described I saw no reason to classify it at all. Simply storing ignitable materials does not in and of itself demand classification.

It is important to note the facility described so far is not within the scope of Article 516; nor is it within the description in 500.5(B)(2).

 

[brantmacga]

(2) Class1, Division 2.

A Class 1, Division 2 location is a location
(1) In which volatile flammable liquids or flammable gases are handles, processed, ,or used, but in which the liquids, vapors, or gases will normally be confied within closed containers or closed systems from which they can escape only in case of accidental rupture or break-down of such containers or systems or in case of abnormal operation of equipment.


in this area, flammable liquids are stored and transfered from one container to another (just realized i did not point this out in original post!!). why is this not a hazardous location?? thanks for those replies!

 

[rbalex]

...
in this area, flammable liquids are stored and transferred from one container to another (just realized i did not point this out in original post!!). why is this not a hazardous location?? thanks for those replies!

You have just changed the description from unclassified to Division 1. :roll: See 500.5(B)(1), FPN No.1 (1).

Thankfully, FPNs aren't enforceable.

When taken to its logical conclusion, the last clause in 500.5(B)(2) (...or in case of abnormal operation of equipment.) makes the whole world at least Division 2.

The NEC is a fine document to address installations in Classified locations; it is a horrible document to use when attempting to classify a location in the first place. Well, Articles 511 to 516 aren't too bad when the facility is within their scope.

What is overlooked in the NEC descriptions is the amount of flammable materials handled and other elements relevant to classification.

Other standards such as NFPA 497 or API RP500 do not address your application directly either unless you wanted to do a formal fugitive emissions analysis. In my opinion, sound judgment (a valid method in both NFPA 497 and API RP500), would indicate that there is no need to classify the location.

 

[brantmacga]

ok thank you very much for your help! i really need more training in hazardous. for some reason it has been hard for me to decipher this in the code.

 

[boater bill]

It is certainly one of most difficult to understand. I lost a job when the boss said Class 2 div 1 only needed a NEMA 4 enclosure. I fought and backed up the data best I could. Machine shipped NEMA 4 and was returned by purchaser by not meeting CL2 Div 1 requirements. I was told to pack my bags even though I was right.

Just keep researching and asking questions and it will get clearer year by year. There is no substitute for experience.

Good luck.