EBU

[Jimmy7]

I’m looking at a set of drawings for a science building at a college. The electrical and the mechanical rooms have EBU’s along with lights that are attached to an emergency circuit. I was wondering if the EBU’s are there for any lag in the generator startup? Would there be any other reason?

 

[roger]

Yes, typically they are for instant lighting during transfer to EM power, the exact reason they are required in certain 517 locations.

 

[ron]

I’m looking at a set of drawings for a science building at a college. The electrical and the mechanical rooms have EBU’s along with lights that are attached to an emergency circuit. I was wondering if the EBU’s are there for any lag in the generator startup? Would there be any other reason?

Because the generator will only start when there is a loss of power at the ATS level of distribution. If the local branch breaker trips in an Electrical or Mechanical Room, some engineers add local battery backed up fixtures (more than what is required by code minimum) so there will be some lighting in these areas that can be more hazardous or needed for restoration.