NEWBIE DISCONNECT Q'S

[new_ee]

I have a few questions about disconnects. Mostly about disconnects for A/C equipment.

1) Are disconnects required to have some sort of fuse or breaker if the circuit is also protected by a circuit breaker in a panel?

2) If so, will it be a fuse or breaker in the disconnect (typically)?

3) Is the fuse sized the same as the breaker?

4) Is this redundant? To have a breaker and either fuse/breaker in the disconnect?

5) Disconnects are rated 15, 30, 60, 100 Amps. If I have a 30A fuse/breaker can I use a disconnect rated 30A or do I have to go up to 60A?

I understand this is a lot. If its not making any sense let me know and I'll try to explain myself a little better. Oh and code references are always welcome too (sometimes these things are staring you right in the face).

 

[iwire]

Re: NEWBIE DISCONNECT Q'S

Originally posted by new_ee:
I have a few questions about disconnects. Mostly about disconnects for A/C equipment.

1) Are disconnects required to have some sort of fuse or breaker if the circuit is also protected by a circuit breaker in a panel?

No, but the equipment the disconnect serves may require fuses.

Originally posted by new_ee:
2) If so, will it be a fuse or breaker in the disconnect (typically)?

Well a fused disconnect will have fuses, a breaker enclosure will have breakers.

Originally posted by new_ee:
3) Is the fuse sized the same as the breaker?

Maybe, there it depends on the application.

Originally posted by new_ee:

Originally posted by new_ee:
4) Is this redundant? To have a breaker and either fuse/breaker in the disconnect?

Sometimes, other times it is required by the equipment being served.

5) Disconnects are rated 15, 30, 60, 100 Amps. If I have a 30A fuse/breaker can I use a disconnect rated 30A or do I have to go up to 60A?

A 30 amp disconnect can accept a 30 amp fuse and can handle 24 amps continuous or 30 amps non-continuous.