Q on Seismic Installation.......

[dionysius]

What are the seismic requirements for top out conduits from large switchgear panels in West Coast seismic regions???

Lets be specific. Large flat roofed 96" hi x 41" deep x 80" wide switchboard panel. The NEMA-3R outside panel is mounted free-standing on a concrete slab with bottom bolted per manf seismic specs. There are 3" PVC conduits exiting the top and climbing the adjacent concrete wall 25' to 30' and entering the building via 90 deg turn fittings.

Are there any special bracing or flexibility requirements that the electrical Inspector will/can call for?? I find no NEC regs.

 

[gadfly56]

What are the seismic requirements for top out conduits from large switchgear panels in West Coast seismic regions???

Lets be specific. Large flat roofed 96" hi x 41" deep x 80" wide switchboard panel. The NEMA-3R outside panel is mounted free-standing on a concrete slab with bottom bolted per manf seismic specs. There are 3" PVC conduits exiting the top and climbing the adjacent concrete wall 25' to 30' and entering the building via 90 deg turn fittings.

Are there any special bracing or flexibility requirements that the electrical Inspector will/can call for?? I find no NEC regs.

Ask the engineer. Make it his headache.

 

[dionysius]

Ask the engineer. Make it his headache.

Excellent point but he disowns it. If there are no NEC regs then perhaps no need to push it. I do not want to open Pandora's box.

 

[steve66]

There are building code requirements and FEMA requirements.

The requirements are very confusing, and hard to figure out. The best guide I've found so far is the Cooper Bline Seismic Restraint catalog.

 

[gadfly56]

Excellent point but he disowns it. If there are no NEC regs then perhaps no need to push it. I do not want to open Pandora's box.

I'm not impressed by his professionalism. Put the screws to him and issue a formal RFI. At least force him to cough up the standards he wants you to use. In the meantime:

Cooper B-Line

FEMA

ECM article

Gripple

United Forces spec

Certification for EATON products

A primer from GE

Looks like the requirements are driven by the building code, not the NEC. Good luck.

 

[ron]

Always a PITA issue.

I'm struggling with it now on a project in Hawaii.

I'm going to have to hire an Engineering sub-consultant for it.