Can any one add to the list below as to the differance betw
een a manhole and a vault? Thanks
1.A manhole is always underground and the equipment within it is usually submersed in water.
2.Access to the manhole is through an opening from above ground.
3.Manholes are not ventilated.
1.A vault...
Can anyone clarify why the NEC treats the medium voltage (> 600v < 38kv)protection differently as compared to low voltage (<600v)systems? It appears that the code is only requires short circuit protection for medium voltage system (with the exception of motors and transformers) while in low...
Can any one tell me when we need to be concerned with the resistance to ground (earth) of a grounding electrode system in an industrial or commercial installation with system(s) operating less than 600 volts? It appears that the NEC is not concerned with it, however, it requires to connect the...
