How do you wire in a GFPD between the PV array and the MPPT in a system with the negative terminal of the battery bank connected to the central grounding bus bar?
I am intending to install a MidNite Solar MNDC-GFP63 Ground Fault Circuit Breaker 63A
Apparently, with this particular GFCB, the battery negative cannot be connected to the central grounding point. Currently, my system is wired as the Victron diagram below.
Hi Glen,
If you are keen to include a GFPD and retain the negative to ground bond at the battery, this GFPD from Morningstar looks like it may do what you want...
Web link:
https://www.morningstarcorp.com/products/ground-fault-protection-device/
Data sheet:
Again please consult a suitably qualified electrician regarding this and don't solely rely on the guidance / suggestions provided in this community Forum.
Thank you Mark for your response. I agree, while this community should not be considered the absolute reference but, they sure have been of great assistance!
I have talked with local PV installers and it appears the requirement for a RCD/GFPD is a Code requirement here in Canada but not widely installed in mobile applications. Surprisingly, I have only found two manufacturers producing applicable RCD/GFPD's.
Having said that, I may be overcomplicating my system by incorporating a RCD/GFPD between the PV array and MPPT. I will have a 20A breaker on the positive leg and a disconnect on both the pos. and neg. legs prior to connection with the MPPT. The PV frames, MPPT case and Neg. battery lead are connected to the central grounding bus bar. The 110 VAC receptacles throughout the travel trailer are GFCI protected, so I think I'm good.
Did you see this wiring diagram?
http://www.midnitesolar.com/pdfs/DC-GFP.pdf
Naturally, you can't ground the negative bus bar as this fault current will need to flow from the negative bus bar through the device to ground in order for it to activate.
Please bear in mind that, although willing to help, this community should not be considered the absolute reference for wiring diagrams and layouts. Wiring rules and regulations vary across the world, so absolute advice should be provided by your local electrician.
Thank you WKirby for your response. Yes, I have reviewed these diagrams. It appears this GFPD is designed for land based structural applications. As my application is mobile, I must maintain a battery negative connection to the central chassis ground.
I would like some clarity on this statement; Note: For Battery-less DC-GFP installations connect the white wire to PV negative rather than Battery negative.
Is it possible to maintain a battery negative ground with this "Battery-less" configuration?
Failing that, does anyone have a solution for installing a GFPD/RCD between the PV array and an MPPT in a system with a battery negative connection to the central chassis ground?
Thank you WKirby for your response. I agree, while this community should not be considered the absolute reference but, they sure have been of great assistance!
I have talked with local PV installers and it appears the requirement for a RCD/GFPD is a Code requirement here in Canada but not widely installed in mobile applications. Surprisingly, I have only found two manufacturers producing applicable RCD/GFPD's.
Having said that, I may be overcomplicating my system by incorporating a RCD/GFPD between the PV array and MPPT. I will have a 20A breaker on the positive leg and a disconnect on both the pos. and neg. legs prior to connection with the MPPT. The PV frames, MPPT case and Neg. battery lead are connected to the central grounding bus bar. The 110 VAC receptacles throughout the travel trailer are GFCI protected, so I think I'm good.
