Wiring SPD with PV- and ground tied together

[David]

I currently have my PV array 230ft.+ away with separate PV+, PV-, and ground coming into the basement panel that has the PV-, and ground tied directly together in the panel.  This is connected to an MX-60 and was installed before the GFP requirement.  How do I properly wire the SPD for this situation and is it effective in this configuration?

If I use a Midnite Classic, instead of connecting the PV- to the same busbar the PV ground is currently connected to I would connect the PV- directly to the PV- terminal in the Classic, correct? 

[Watt]

I currently have my PV array 230ft.+ away with separate PV+, PV-, and ground coming into the basement panel that has the PV-, and ground tied directly together in the panel.  This is connected to an MX-60 and was installed before the GFP requirement.  How do I properly wire the SPD for this situation and is it effective in this configuration?



If I use a Midnite Classic, instead of connecting the PV- to the same busbar the PV ground is currently connected to I would connect the PV- directly to the PV- terminal in the Classic, correct?

Do you have a combiner at the Array?  If so, you can install one or two SPD's at the array.  If using one SPD, PV+ to red, PV- to black and green to earth.  If using two, one SPD would be on my PV+ to red and black then green to earth.   The other SPD would be PV- to red and black then green to earth.  Even if you don't have a combiner, SPD's can be added easy enough at the array.  I'm sure you have the array properly grounded to a grounding system adequate for your PV array location?  Yes, the SPD will be effective at the array if you have a properly designed earth ground system.  However, I don't think I would bring the ground from the array into the basement due to the distance from your array to your service entrance.  I would elect to add an additional earth ground system at the basement service entrance or tie into my grid earth system if you have the grid and have common earth from the grid service entrance to your inverter.  Kind of hard to guess though.  Will you be adding a GFP device to your system?  I'd add a SPD to the basement panel PV + and - in buss as well and green to the DC earth ground system which would also be connected to the classic or your outback mx.  The PV- and Battery - are common on the Classic so you just need the one conductor from the negative buss to the classic.  Just do as much research as you can.  Ultimately, it is up to you to be educated in all things ground and think about possible voltage potential.

As far as connecting the ground from the array to the negative buss along with your classic, be careful as you may get a huge potential to your classic during a strike or near strike at your arrays or even your house equipment or both.  The idea is to get the strike to earth ground and not help develop a path between electrical devices.

Also, I'm no expert so......