CSA/NEC Class 1 Div 2 Group B motor?

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mrt

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Gentlemen - Our customer requires a 5hp "Class 1, Div 2, Group B" motor on a compressor system we are supplying but it seems impossible to find such a motor in the US market. Is the CSA designation the same for this motor rating? If we provide a NEC Class 1, Div 1, Group D, T2D are we opening a can of worms for the end users AHJ as to acceptablility? I am inclined to ask the end user to re-evaluate the rating required and if possible, accept the Class 1, Div 1, Group D T2D for the application. Any thoughts would be appreciated. - mrt

p.s. - The switches on the project are all NEMA 7.
 

don_resqcapt19

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Illinois
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retired electrician
mrt,
If this is a standard 3 phase motor without any internal contacts, the NEC does not require that the motor be listed for the location.
Look at the last part of 501.125(B).
In Class I, Division 2 locations, the installation of open or nonexplosionproof enclosed motors, such as squirrel-cage induction motors without brushes, switching mechanisms, or similar arc-producing devices that are not identified for use in a Class I, Division 2 location, shall be permitted.
Don
 

mrt

Member
Thanks for the reply Don. The application is 3ph. 460 VAC. Again, I think it will be difficult to find a "non-sparking" motor as you describe. Typically, we use TEFC premium efficiency 1800 rpm motors from TECO or Toshiba on our compressor packages but this application request causes me concern. I'm trying to get a better understanding of what my options are for "Class 1, Div 2, Group B" (hydrogen gas environment) service. - mrt
 

don_resqcapt19

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Illinois
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retired electrician
mrt,
All standard 3 phase induction motors are "non-sparking". TEFC is all we use in Class I, Division 2 areas and we have a number of motors in a Group B areas. These are all 3 phase 480 volt motors.
Don
 

rbalex

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Professional Electrical Engineer
Don's responses are all correct for US domestic installations; however, if the final installation is in Canada, the motor will still need CSA certification. Many US manufacturers can provide it though, they just can't provide UL certification.

Note: Class, Division, and Group designations are the same under "Division" classifications.
 

Spaz

Member
don_resqcapt19 said:
mrt,
If this is a standard 3 phase motor without any internal contacts, the NEC does not require that the motor be listed for the location.
Look at the last part of 501.125(B).
Don

Appendix J in the CSA electical code has a somewhat similar statement under the Class 1 Div 2 wiring section. Look it up and judge for yourself - I don't have the code in front of me...I can find it Monday if you like.

I have a few questions of my own, but I started a new thread. Please check it out...since there seem to be a bit of experience here from my first day exploring this forum. It's about having simultaneous Class 1 div 1 groups C&D hazards for solvent vapors, as well as Class 1 div 2 group B hazards. Thanks!
 
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