when did the 10' rule for meter to panel originate ?

[electrofelon]

Thanks for posting. It’s more common to see PVC even outside, but EMT would be better outside on commercial services

I believe Seattle fully prohibits EMT everywhere for service conductors.

 

[kwired]

What is their reasoning for prohibiting EMT for service conductors in WA?

 

[electrofelon]

What is their reasoning for prohibiting EMT for service conductors in WA?

Who knows, likely another one of these stupid "it seems like a good idea" things made without any evidence of a problem by someone who doesn't have any practical experience to be making such decisions.

 

[jaggedben]

Perhaps, like in San Francisco, it's a holdover from before they started using the NEC. I know SF wrote its own unique electrical code before the state started adopting the NEC. They also have a local ammendment that deletes all references to wiring methods for services other than rigid metal conduit. My impression is that the ammendment is more or less the old SF city code rule, which may date back to when EMT was invented. So it's not so much that they singled out EMT to prohibit it, as that they just never allowed anything but rigid, ever. It's among other SF oddities such as that, technically, you're supposed to mark a high-leg purple, not orange.

That said, no one uses EMT for services around here.

 

[tom baker]

What is their reasoning for prohibiting EMT for service conductors in WA?

That rule goes to perhaps 1960s. I suspect it’s due to fault current on service conductors. Also WA does not allow SE cable, and limits the type of raceway to only 8 for service conductors

 

[electrofelon]

.

That said, no one uses EMT for services around here.

I have and do use EMT for services. Although depending on the details, the cost of rain tight fittings may make rigid just about the same cost or not much more in which case I would go with rigid.

 

[kwired]

Who knows, likely another one of these stupid "it seems like a good idea" things made without any evidence of a problem by someone who doesn't have any practical experience to be making such decisions.

That what I figured. Other than when corrosion potential is higher I'd rather see EMT than sch40 PVC when it comes to physical protection abilities.

Riser off a meter socket to the service drop (not a mast supporting the drop)I'd rather see EMT than schedule 40 as well. Looks better after a few years than the PVC will look even if it remains intact, at the meter hub is where the PVC is most likely to break if it is going to, next place is any couplings that aren't bell ends of the pipe.