Explosion proof room

[eager2learn]

I am currently working at an auto shop and i need to install exposed conduits in an explosion proof room. I am aware of the explosion proof fittings that need to be installed but im not sure if i need to run coated rigid metal conduit or if i can install rmc without the coating. Please advise

 

[DARUSA]

If I not wrong just RMC with the proper fittings. Will be fine!!!!

 

[acrwc10]

would you define "explosion proof room" a little better. What type of Location is it? Is it a Class 1 Division 2, you can look in Chapter 5 to get started.

 

[don_resqcapt19]

Coated rigid is for corrosion protection. There should be no need for that in this application.

 

[eager2learn]

The room is a storage room. They will will be storing cotainers of grease and oil and things of that nature. So the only thing that i need to do is make sure that i have the right explosion proof fittings for a class 1 division 2 application. Now, with that being said, i also need to make sure that all conduits entering the room for eachsystem has this type of installation. The reason why i say this is because my fire alarm prints arent telling me to install any fittings in this area. All other systems stae that these fittings need to be installed. In addition, emt should not be utlilized in this area if im not mistaken. Please advise

 

[benaround]

JT,

A room with grease and oil would not be a class 1 div 2 installation, but you must follow

the job spec's or RFI the EE.

 

[eager2learn]

Im having a hard time distinguishing what class and division would be appropriate for proper installation. i havent really had a chance to look at code and i apologize - can please advise.

 

[kwired]

If it does not produce combustible vapors, dusts, or ignitible fibers/flyings that would create fire or explosion hazards then it is most likely not a classified area.

500.1 Scope ? Articles 500 Through 504.

Articles 500 through 504 cover the requirements for electrical and electronic equipment and wiring for all voltages in Class I, Divisions 1 and 2; Class II, Divisions 1 and 2; and Class III, Divisions 1 and 2 locations where fire or explosion hazards may exist due to flammable gases, flammable liquid?produced vapors, combustible liquid?produced vapors, combustible dusts, or ignitible fibers/flyings.

The question is who is going to or has already classified the area. Most of the time that is not up to you the installer or even the electrical inspector. Once it has been classified by proper authority then it is up to installer and inspector to see that the installation meets the classification.

Grease and oil are generally not going to create a classified location and storage of flammable liquids in sealed containers often is not either unless it is bulk type containers.

 

[DARUSA]

I don't see why fire alarm system require explosion proof installation ?

 

[MichaelGP3]

Hmm.

Hmm.

I don't see why fire alarm system require explosion proof installation ?

It was a long time ago, but the last distillery I installed a fire alarm in was required by Factory Mutual to be explosion proof. Not only that, we needed to test the air with an explosiometer before plugging in and using any electric drills. I learned a lot on that job about Crouse Hinds and Killark products.

 

[sgunsel]

Storage rooms are generally unclassified, even for flammables.
Some engineers/specifiers have no concept of how to classify an area nor of the consequences for installation and maintenance.