This concerns running PV DC wiring inside a building to connect to the inverter. The EP800 is designed to accept only MC4 connectors. However, this setup does not comply with NEC requirements, which mandate a grounded metal enclosure to protect high-voltage DC conductors when routed indoors.
Any good solutions?
According to NEC 690.31(D) — Direct-Current Circuits on or in Buildings:
Where INSIDE buildings, PV system DC circuits that exceed 30 volts or 8 amperes must be contained IN metal raceways, or Type MC metal-clad cable that complies with 250.118(10), or in metal enclosures.
Hello,
Are you referring to using a grounded metal conduit to protect the high-voltage DC wires when wiring indoors? Specifically, should the photovoltaic high-voltage DC wires be run through conduit? Please run the conduit from the roof, through the DC control box, and then make MC4 connectors to connect to our energy storage photovoltaic input. For specific guidance, please consult a local photovoltaic installer or electrician.
Thanks for sharing the image! I’m not concerned about where the ground is connected. What I’m pointing out is that the wires attached to the MC4 connectors in your image aren’t protected by a metal shell, which violates the NEC requirement I mentioned earlier.
One potential solution is using metal-clad (MC) cable, which provides the necessary physical protection. However, the inverter is designed to accept only MC4 connectors, and MC cable isn’t compatible with MC4 in a clean or code-compliant way. It’s a clunky and unprofessional combination that could raise inspection issues or compromise long-term reliability.
Thanks for your info! I’m an electrician, and my question concerns the routing from a DC control box to the inverter’s MC4 ports. According to NEC 690.31(D), a metal enclosure is required to provide additional grounding protection, as I mentioned earlier. However, since the inverter only accepts MC4 connectors, it’s difficult to find a clean solution. Connecting metal-clad (MC) cable directly to MC4 connectors or enclosing the entire area in a metal raceway both seem awkward and unprofessional.
I think that is the only solution ATM, is to use MC cable to MC4, with a J-Box or strap within 6 feet, and have the jacket grounded. I’ve seen several different installs of EP800/900 and none had MC cable, only a PV whip from a J-Box/Combiner Box adjacent to the ESS. If you find a better solution let us know.
Same here. That’s the best I can envision for now. Adding an MC connector between the MC cable and the MC4 would make the setup look more professional. I hope Bluetti eventually releases an adapter box that converts MC4 connections to hardwired terminals.
Just to clarify, this issue only applies to indoor ESS installations.
You could probably use a PV entry gland, sized to not cover up the PV disconnect switch, to cover the MC4 connectors, run MC to it. Something like THIS, you would have to replace the watertight gland with one MC compatible. Mount it with four small screws.
I’ve seen someone run EMT to a Southwire 6x6" jbox that is mounted to Victron equipment to run the PV wires in. Its not pretty but it is code compliant. You could also use a standard construction 4x4 steel box with plate a JBOX.
