lighting in class I , Div II

[dicklaxt]

What Dick is stating is somewhat true. Per NEC 501.130(B):

(1) Luminaires. Where lamps are of a size or type that
may, under normal operating conditions, reach surface temperatures
exceeding 80 percent of the ignition temperature
in degrees Celsius of the gas or vapor involved, luminaires
shall comply with 501.130(A)(1) or shall be of a type that
has been tested in order to determine the marked operating
temperature or temperature class (T Code).

The NEC Handbook and the NFPA's book "Electrical Installations in Hazardous Locations" both explain that "previously called Vaportight" fixtures are acceptable for C1D2 use. So if the fixture surface temp exceeds 80 of the ignition temp of whatever the hazard is then it has to be explosionproof or marked with a T Code. I am not sure how you would get a T Code unless it was listed for C1D2 but still Dick is techinically correct. The NEC does not necessarily REQUIRE that a luminaire be listed as C1D2.

Gadfly:

Division 1: always present (not techincally correct- "can exist normal operating conditions" is the correct phrase and no they are not quite the same thing)
Division 2: present on occasion or if equipment fails or something breaks (good explanation- "in case of accidental rupture or breakdown of such containers or systems or in case of abnormal operation of equipment")

So a gas/vapor may still be "present on occasion" but if it is so due to normal conditions then it would be a C1D1. It does not have to be "always present" to qualify a C1D1.

Thanks, HEY!!!! I got an ally, the sky is going to fall for sure,,,,,,,its all for a good cause and learning curve.

 

[weressl]

The bottom line is Vapor/Dust Proof fixtures are acceptable in paint booths when recessed in the wall or ceiling(which is most always the case).

Not true.

If they are surface mounted then they must be Explosion Proof.

dick

Incorrect. There is no such a 'listing' as Explosion Proof.

"When I use a word," Humpty Dumpty said, in rather a scornful tone, "it means just what I choose it to mean?neither more nor less."

 

[dicklaxt]

Not true.




Incorrect. There is no such a 'listing' as Explosion Proof.

"When I use a word," Humpty Dumpty said, in rather a scornful tone, "it means just what I choose it to mean?neither more nor less."

I'm sorry if I used the word out of context, I'm sure we all knew what the intent was in this discussion.

Here's a quoted text,,,,,,,,,,,from a Code Digest that I guess I should have prefaced my statement with, then you would have known my intent. I guess I should have paid more attention to my English Teacher's and studies of the English language.

Quote:

Explosionproof Apparatus...... Apparatus enclosed in a case that is capable of withstanding an explosion of a specified gas or vapor that may occur within it and of preventing the ignition of a gas or vapor surrounding the enclosure by sparks,flashes,or the explosion of the gas or vapor within,and that operates at such an external temperature that a surrounding flamable atmosphere will not be ignited thereby.

FPN: For further information, see ANSI/UL 1203-1994, Explosionproof and Dust Ignition-Proof Electrical Equipment for Use in Hazardous (Classified ) Locations.

This post is no longer fun or informative so I'll bow out of this discussion.

dick

 

[weressl]

I'm sorry if I used the word out of context, I'm sure we all knew what the intent was in this discussion.

Here's a quoted text,,,,,,,,,,,from a Code Digest that I guess I should have prefaced my statement with, then you would have known my intent. I guess I should have paid more attention to my English Teacher's and studies of the English language.

Quote:

Explosionproof Apparatus...... Apparatus enclosed in a case that is capable of withstanding an explosion of a specified gas or vapor that may occur within it and of preventing the ignition of a gas or vapor surrounding the enclosure by sparks,flashes,or the explosion of the gas or vapor within,and that operates at such an external temperature that a surrounding flamable atmosphere will not be ignited thereby.

FPN: For further information, see ANSI/UL 1203-1994, Explosionproof and Dust Ignition-Proof Electrical Equipment for Use in Hazardous (Classified ) Locations.

This post is no longer fun or informative so I'll bow out of this discussion.

dick

A lighting fixture for Class I, Division 1 location is not labeled 'ANSI/UL 1203-1994'. It is labeled UL 844. To simplify it, for a lighting fixture it is insufficient to contain/withstand an internal explosion it also have to have a tested thermal profile - under specified voltage excursions - that it does not produce a hot-spot on the external surface of the apparatus that is greater than 80% of the specified(labeled) T-rating.

A luminaire labeled for Class I, Division 2 does not have to meet the above withstand test, however the temperature restriction described above applies to ANY point on the fixture be it internal or external.

Conversely a 'flush mounted' fixture in a paintbooth wall would need to meet at least the temperature restriction on the surface that is in contact with the hazardous atmosphere and only if the paintbooth is under negative pressure in relationship to the 'vaportight' fixture indicated by you, which would be difficult to maintain and prove that it is maintained precisely since its vaporproof construction. (Now if the 'vaporproof' construction is only the optics connecting to the flushmount wall and the fixture is otherwise NEMA 1 or similar, the task is more likely achievable.)