- Location
- Lockport, IL
- Occupation
- Retired Electrical Engineer
There will be a transformer in one building, and a long underground run towards another building. Conduits will penetrate the floor of the second building, then rise up to the electric room on the second floor. The conduit riser will be encased with 2 inches of concrete, until within 15 feet (WA State limit) of a fused disconnect. The fused disconnect will serve as both the required building disconnecting means and the overcurrent protection for the transformer secondary conductors.
I should think that you would want the incoming conductors to land on the disconnect switch terminals, and have the fuses on the load side of the switch. That way, you can safely replace the fuses by first opening the switch. But I read the tap rule in 240.21(C)(4) as saying that the conductors have to land on the fuses. What say you?
Related question: 240.21(C)(4)(4) requires the disconnecting means to be ?readily accessible.? I think this has been debated here before, but if the fused disconnect is inside a locked electrical room, is it still ?readily accessible??
I should think that you would want the incoming conductors to land on the disconnect switch terminals, and have the fuses on the load side of the switch. That way, you can safely replace the fuses by first opening the switch. But I read the tap rule in 240.21(C)(4) as saying that the conductors have to land on the fuses. What say you?
Related question: 240.21(C)(4)(4) requires the disconnecting means to be ?readily accessible.? I think this has been debated here before, but if the fused disconnect is inside a locked electrical room, is it still ?readily accessible??