Class II, Div 1, Group F - conduit and LFMC help

emiller233

Senior Member
Location
pittsburgh, pa
looking for guidance/confirmation that I'm reading the code properly for this, as I'm not familiar with it...
Class II, Div 1, Group F (coal dust)

we have a small hydraulic power unit that we will simply be wiring all of the devices back to a junction box that's mounted onto the skid. from there the customer will handle it. My understanding is that i can use a combination of RMC and LFMC to do this as long as all the LFMC fittings are listed for this area. and i believe all ABB (Thomas & Betts) fittings are, such as the 5351 but i don't see any listings on their data sheets for this. i believe that is bc the NEC says it is acceptable to use it in those areas? same for other conduit fittings such as LB's, TB's, ect...
They still haven't gotten back in touch with me yet...?

for the bonding of the LFMC, should we land its bonding wire on the self grounding terminal blocks inside of the junction box? as well as the grounding screws inside of the devices (if there are any?)

I believe all wire types are acceptable at this point? THHN, multi-conductor, ect?

no conduit seal fittings need to be used anywhere?

any other thing's that i need to be aware of. that i missed...?


NEC 502.10(A)
NEC502-10.PNG
 

don_resqcapt19

Moderator
Staff member
Location
Illinois
While actual explosion proof sealing fittings are not require, you must limit the transmission of dust using one of the methods in 502.15.
 

emiller233

Senior Member
Location
pittsburgh, pa
While actual explosion proof sealing fittings are not require, you must limit the transmission of dust using one of the methods in 502.15.
I seen that but don't think that applies here bc both of my enclosures (Jbox and device) is required to be dust-proof, and the code book says "Where a raceway provides communication between an enclosure that is required to be dust-ignitionproof and one that is not".

did i read it incorrectly?
the skid is small (10 x 10') and all devices and Jbox will be in the same area


NEC502-15.PNG
 

don_resqcapt19

Moderator
Staff member
Location
Illinois
Yes, as long as all of the enclosures are in the Class II, Division 1 location, you are correct that you only have to comply with the wiring methods rule in 502.10.
 
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