I'm working on a sewer pump station project and want to connect pump power from the wet well (C1D1 location) to a junction box (j-box) outside the wet well without needing permanent type sealing fitting, the j-box will only contain terminal block connections. I have gathered some ideas from this site and other places but seems unclear if terminal blocks in the non-explosion proof j-box in a C1D2 location would be allowed.
Current design is a "sleeve" from the wet well to the exterior of the electrical building for running pump power cords , with the sleeve terminating 6 inch above final grade and a 3-ft min air gap from the end of the sleeve to the bottom of the j-box, pump cords will be shielded by a perforated metal case. The sleeve can vent gas accumulated in the wet well and according to NFPA 820 creates a rated area of C1D1 at a 3ft radius and C1D2 at a 5ft radius from the sleeve end. This would put the j-box in the C1D2 location, and reviewing 501.10(B)(4) and the associated references it appears terminal blocks would not require an explosion proof j-box, but would still need to meet the requirements under 501.10(B). If we place terminal blocks in the j-box for power 240V, its non-arcing, or non-sparking but it would be incendive. Would terminal blocks be allowed under 500.8(B)(3) as it wouldn't constitute a source of ignition under normal operating conditions?
Current design is a "sleeve" from the wet well to the exterior of the electrical building for running pump power cords , with the sleeve terminating 6 inch above final grade and a 3-ft min air gap from the end of the sleeve to the bottom of the j-box, pump cords will be shielded by a perforated metal case. The sleeve can vent gas accumulated in the wet well and according to NFPA 820 creates a rated area of C1D1 at a 3ft radius and C1D2 at a 5ft radius from the sleeve end. This would put the j-box in the C1D2 location, and reviewing 501.10(B)(4) and the associated references it appears terminal blocks would not require an explosion proof j-box, but would still need to meet the requirements under 501.10(B). If we place terminal blocks in the j-box for power 240V, its non-arcing, or non-sparking but it would be incendive. Would terminal blocks be allowed under 500.8(B)(3) as it wouldn't constitute a source of ignition under normal operating conditions?
