Hello, We're installing a 270 kW system with four 62.5 kW SMA Tripowers that will be mounted inside. We'll be using #10 PV wire in snaketray on the roof, then transitioning to EMT to go down the side of the building and inside. I'd like to pull continuous runs and avoid any terminations. The Tripowers are intended to be installed outside, and only allow for MC4 connections, so just crimping another one on the same PV wire seems easiest, less voltage drop etc. The customer wants them inside and has plenty of room, so that's what we are doing. The problem I have is how to transition from the snake tray into the EMT. I expect to install a junction box there, but need a fitting for the transtion. Does any body have a bright idea? I thought of using Heyco connectors, but the crew is going to hate threading 50' of 8 wires through the rubber gland. Total of 48 wires! I was thinking of a weatherhead, or just a plastic fitting jammed tight with duct seal and caulk, but yes, those are half ass ideas. So any suggestions would be appreciated. Btw, this is in Wisconsin, with plenty of freezing, thawing, snow, rain, and wind etc.
How to Transition PV Wire to Conduit
- Thread starter Rock-Noll
- Start date
jaggedben
Senior Member
- Location
- Northern California
- Occupation
- Solar and Energy Storage Installer
Use additional MC4s right outide the j-box? (Or inside?)
TwoBlocked
Senior Member
- Location
- Bradford County, PA
- Occupation
- Industrial Electrician
If you are doing homeruns with the PV wire, consider coming into the bottom of a box through chase nipples and out the upper side with the EMT. Should be plenty of drainage that way. I suppose it can be argued that you should not have holes bigger than 1/4" for drainage. Maybe duct seal the chase nipples and drill some holes for drainage.
electrofelon
Senior Member
- Location
- Cherry Valley NY, Seattle, WA
how about weather heads? I dont even think you need a box.
In residential we just bend the end of the EMT coming up from the ground down a bit as sort of a weather head / drip loop ......leave it in "free air" (not in a box) and strap it to the side of a rail usually.....put a raintight EMT connector on the end and bonding bushing on it...........and feed all the PV wire from the array through.
I will say, we almost always transition to THHN. Much smaller EMT needed for THHN..... about half the size. PV wire is thick and not slick either.
I dont know what critters you might get inside an open ended conduit like that though..... as you're talking about a pretty big conduit it seems?
I will say, we almost always transition to THHN. Much smaller EMT needed for THHN..... about half the size. PV wire is thick and not slick either.
I dont know what critters you might get inside an open ended conduit like that though..... as you're talking about a pretty big conduit it seems?