Seperate L1 L2 runs in two separate sch40 pvc

S

Skyline Electrical

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Location
wa
Occupation
electrician
I've got a client that has two 1in pvc runs from a crawlspace to a carport under a poured driveway. My current wire fill calc is not up to snuff with the feed and comm conductors I need to run, if I only consider 1 of the conduits.

Can I split the L1 and L2 feeds in a pvc box on one end, run each leg in its own PVC with N and G, and combine again on the far side of the run in another pvc box? I've found some guidance on more industrial/commercial splitting of phases in this manner and mostly just to ensure that there is no metal rings in the run for inductance. I'm looking at 300.3b3

The 2 conduits share the same 'trench' and the entire installation would be nonferrous

Am I correct in this interpretation?
 
You have two issues: conductors in separate conduits and parallel conductors.

It sounds like you meet the requirements for isolated phase installation (non-ferrous conduit, same trench...).

But you probably can't have two separate neutral wires and then combine them, because they won't meet the parallel conductor rules.
 
Skyline Electrical said:
Can I split the L1 and L2 feeds in a pvc box on one end, run each leg in its own PVC with N and G, and combine again on the far side of the run in another pvc box?
Click to expand...
Can you further describe how many conductors are in each raceway and what they are? Sounds to me like two conductors is each raceway is that what you're proposing? What size and type of PVC?
 
Skyline Electrical said:
Can I split the L1 and L2 feeds in a pvc box on one end, run each leg in its own PVC with N and G, and combine again on the far side of the run in another pvc box?
Click to expand...
Yes, except that you wouldn't double the N conductor, you'd just pick one of the two conduits and run a single full-sized (whatever size you need) neutral in it.

Mixing communication and power conductors in the same conduit is another issue. If you could make it work, a better solution would be to use one conduit for communications only, and one for the power conductors only.

Cheers, Wayne
 
I don't read the OP as having any parallel conductors as it would make no sense to do so. Sounds like 4 conductors in two raceways but who knows.
 
What i initially proposed in OP
PVC Jbox > 1in PVC: L1 N G ..............> PVC Jbox
..................> 1in PVC: L2 N G comms >



This installation is for a 22-26kw standby generator so the 'comms' will end up being 6x14ga and don't make a huge difference in my fill calc. The main problem is the size of main conductors. I'm leaning towards 22kw purely on baseloads in the house and wire sizing. For the 22kw it'd be 3ga cu

Would this same setup meet code if the runs as follows and meet isolated phase requirements and parrallel conductors rule


PVC Jbox > 1in PVC: L1 N G...........> PVC Jbox
.................> 1in PVC: L2 G comms >
 
You do not have a parallel feeder so the whole circuit must be in one conduit. I agree that if the two PVC raceways are side by side it would not be a problem electrically but it's still a code issue
 
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