overkill94
Member
- Location
- California
I'm doing a third-party inspection in a cl I, div II location and they're using installation techniques I'm not familiar with.
1. Instead of a normal pressurized purge or an explosion-proof panel, they have external air constantly blowing through the panel and some sort of moisture gauge
2. Some motors are rated for cl I, div II but others are TEFC, and some motors are regular Design B, insulation class F
3. Another panel isn't purged or explosion-proof but all components inside (mostly 120 VAC and 24 VDC) are rated for cl I, div II except for some fuseholders and a low voltage counter (motor hours I think)
The customer seems pretty confident that these are all acceptable practices except for maybe the Design B motor and the fuseholders/counter. When I looked through NEC articles 500/501 I ended up with more questions than answers. What say you, experts?
1. Instead of a normal pressurized purge or an explosion-proof panel, they have external air constantly blowing through the panel and some sort of moisture gauge
2. Some motors are rated for cl I, div II but others are TEFC, and some motors are regular Design B, insulation class F
3. Another panel isn't purged or explosion-proof but all components inside (mostly 120 VAC and 24 VDC) are rated for cl I, div II except for some fuseholders and a low voltage counter (motor hours I think)
The customer seems pretty confident that these are all acceptable practices except for maybe the Design B motor and the fuseholders/counter. When I looked through NEC articles 500/501 I ended up with more questions than answers. What say you, experts?