NEC 517 violation

[mbrooke]

Did another 50/50 complete backup but subdivided. Not to NFPA70- but- but allows for step loading of the gensets. And smaller ATSs.

Panels feeding general areas are via tapped riser, panels for critical areas get dedicated conduit. The idea is that a riser approach is more economical, but during a fire on any floor the riser can clear without much concern.

Same 50/50 for life safety and critical.

 

[synchro]

This is outside of my areas of expertise, but with all generators paralleled on one bus gutter as in post #37 does that incur any significant extra risk since a sustained bolted fault in the gutter (even though unlikely) could potentially disable all the generation? There probably are always going to be some common points of failure but that one seems to stick out just because of the large scale of the common bus.

Also, do engine powered generators have any elevated level of risk for initiating fires? If so it would seem wise to have a fire door separating a least two separate rooms of generators to reduce the risk of a complete outage. Obviously a separate building would be even better but less likely to be implemented. But those design choices are usually beyond the purview of the EE's.

 

[mbrooke]

This is outside of my areas of expertise, but with all generators paralleled on one bus gutter as in post #37 does that incur any significant extra risk since a sustained bolted fault in the gutter (even though unlikely) could potentially disable all the generation? There probably are always going to be some common points of failure but that one seems to stick out just because of the large scale of the common bus.

Also, do engine powered generators have any elevated level of risk for initiating fires? If so it would seem wise to have a fire door separating a least two separate rooms of generators to reduce the risk of a complete outage. Obviously a separate building would be even better but less likely to be implemented. But those design choices are usually beyond the purview of the EE's.

Precisely my reasoning for not wanting them on a common busbar. That and the cost of paralleling hear along with its common mode failure solidify my opinion.

Separate generator rooms is also my desire- I've heard of gensets exploding. I'd think the risk would be even greater with a "battle switch"