Many schools in my area are not building additions when they need to expand. There is a proliferation of prefab classrooms. These are free standing doublewide mobile home trailer type prefabs that are placed on a side lawn next to the school and then tend to multiple as the years go by.
The school job that I inspected today had a 600amp exterior pedestal disconnect feed from the "regular" school building. At some point in the past, before my time as inspector here, 2 doublewide prefabs were plopped down on the lawn nearby and feed underground from that 600amp pedestal. My inspection today was the trench to a newly arrived third prefab and the EL contractor was installing it the same way as the other 2.
The doublewides come as 2 seperate trailers that are connected together and each half has a 100amp panel for all of the wiring in that half. When installation is complete, there is no wall between the 2 halves. There is also no electrical connections between the halves.
The trench that I looked at duplicated the other previous trailer feeds and had 2 conduits from the 600amp pedestal laying next to each other and running down the trench to the trailer but then separating at the trailer and entering the 2 panels separately. This struck me as a violation of 225.30. I don't see that any of the "unless" items in (A) thru (E) apply, but I'm not confident that I'm making the right call.
Exactly what kind of installation is covered by the last sentence in 230.2 [the sentence that starts by saying, "For the purpose of 230.40, Exception No. 2 only"] ?
Would this installation be compliant if it was a service under 230.2 / 230.40 but is not compliant for a feeder under 225.30 ?
What do you think ?
David
The school job that I inspected today had a 600amp exterior pedestal disconnect feed from the "regular" school building. At some point in the past, before my time as inspector here, 2 doublewide prefabs were plopped down on the lawn nearby and feed underground from that 600amp pedestal. My inspection today was the trench to a newly arrived third prefab and the EL contractor was installing it the same way as the other 2.
The doublewides come as 2 seperate trailers that are connected together and each half has a 100amp panel for all of the wiring in that half. When installation is complete, there is no wall between the 2 halves. There is also no electrical connections between the halves.
The trench that I looked at duplicated the other previous trailer feeds and had 2 conduits from the 600amp pedestal laying next to each other and running down the trench to the trailer but then separating at the trailer and entering the 2 panels separately. This struck me as a violation of 225.30. I don't see that any of the "unless" items in (A) thru (E) apply, but I'm not confident that I'm making the right call.
Exactly what kind of installation is covered by the last sentence in 230.2 [the sentence that starts by saying, "For the purpose of 230.40, Exception No. 2 only"] ?
Would this installation be compliant if it was a service under 230.2 / 230.40 but is not compliant for a feeder under 225.30 ?
What do you think ?
David