Hey everyone, I recently bought some Growatt MIN 5000 5000TL-X-US inverters, and I found out that they only support MC4 connections. I was hoping to use DC blocks, but I can't even get the case open! I'm running DC wires through underground PVC conduit from my ground mount into the basement where the inverters will be installed. I have a few questions:
1. Is it allowed for the PVC conduit to enter the building?
2. If that's okay, it will end in a junction box near the inverters. What are my options to connect the PV wire from the junction box to the MC4 connectors on the inverters? I thought these connections needed to be in conduit or liquid tight, but I'm not sure. Are there any liquid-tight connectors that can securely connect the PV wires to the MC4?
3. If I decide to mount the inverters outside (I'd love to recycle the heat to warm the basement), what does the NEC say about exposed PV wire outside? Would I have to rethink my entire setup?
Thanks for any advice!
1 Answer
1. You should definitely check your local codes since the rules can vary; I know where I live, DC wires can't run in PVC.
2. Inside the junction box, you can use connectors like Wagos or wire nuts. Once you're inside the conduit, you don't need to keep using PV wire; THHN will do just fine.
3. You can use PV wire outside, but if it's at ground level, it needs to be protected in conduit. So, switching to THHN there would make more sense. Just a heads-up, MC4 connectors typically handle up to #8 wire, so using #6 might be overkill unless you're planning for a long run.
Thanks for the info! I do need #6 because the run is 180 feet from the mount to the inverter, which the voltage drop calculations called for. I see what you mean about switching from PVC to EMT inside the house.
But about those last 3 feet from the EMT to the MC4s on the inverter, are you saying I can use stranded THHN without any enclosure? I want to make sure I'm clear before I talk to my inspector about this.