0 registered members (),
16
guests, and 18
spiders. |
Key:
Admin,
Global Mod,
Mod
|
|
|
Underground requirements
#198140
01/13/11 03:48 PM
|
Joined: Oct 2002
Posts: 830
OP
Member
|
Around here for years when using a trench for burying USE cable in residential areas, it's always said that the requirement was 18", but as I read in the code it's actually 24" unless it's under a residential driveway or parking area. I'm talking about a normal run to a out building from a main panel not running under any concrete or not in conduit. Am I the only one that's been with this assumption? I've think I've even had inspectors tell me 18" before. Any thoughts on this??? Thanks... Also when driving ground rods for a subpanel in a detached building, I'm under the assumption that it is still (2) ground rods at least 6ft. apart and attached to the grounding bar in the subpanel...???
Last edited by sparkync; 01/13/11 03:50 PM.
|
|
|
Re: Underground requirements
[Re: sparkync]
#198146
01/13/11 04:22 PM
|
Joined: Jul 2004
Posts: 9,575
Member
|
300.5 says 24" for direct burial cable/conductors unless this is a residential, single circuit, GFCI at the source end, 120v, 20a max, which can be 12" That loophole also eliminates the need for a ground rod.
Anything else puts you into 225 part II and 250.32 along with the deeper 300.5 requirements.
They put the single residential circuit loophole in there to compromise a safer alternative to running an orange cord through the trees or along the ground. If digging is hard there, RNC at 18" becomes a very attractive option. Personally I would go that way anyhow.
Greg Fretwell
|
|
|
Re: Underground requirements
[Re: sparkync]
#198182
01/14/11 04:41 AM
|
Joined: Aug 2006
Posts: 356
Member
|
Also when driving ground rods for a subpanel in a detached building, I'm under the assumption that it is still (2) ground rods at least 6ft. apart and attached to the grounding bar in the subpanel...??? The 6' rule is valid but i don't think you need two ground rods unless the resistance of the one electrode is higher than 25 ohms.
Be kind to your neighbor, he knows where you live
|
|
|
|
|