Ground for Multiplus inverter

[John.DS99]

I have mounted my new inverter to a wall, and I started thinking about the work I will be doing to get it running. I could move it elsewhere but it is a test setup for me to familiarize myself with it. I have batteries on order, some panels and charge converters around, so not in a big hurry.

The 15 Amp utility (PG&E, California, 1950s house) outlet nearby is connected to a 20 amp fuse in the main distribution panel, and yes I know how to switch it off and the house main switch.''

I haven't paid much attention to the AC in my house and have left it alone for 20 years, but i found there is no ground wire to this outlet..

I located the breaker for this outlet and examined the wire, the ground wire was clipped off the wire. There are green wires alongside the neutrals that go into the conduit, but Lord knows where they go (How would I test that)

Also I pulled the outlet - one Hot & one neutral wire only

So at least this one outlet is ungrounded, and it is possible that the entire house is ungrounded.

I am not going into fixing my house just yet but I do need a good ground at this outlet for the multiplus., I was thinking of grounding to the pole that the electric meter is mounted on. That is how Comcast grounded their equipment.

I am not interested in discussing code as much as setting up this temporary setup properly, I'll think about that later.

The meter is about 15 feet away, so I could run a cable to it scratch off the paint & attach the ground there just like the Comcast cable.

If I did this where would I attach this ground? I can ground my outlet which grounds the AC input, and the ground terminal on the multiplus box.

Does this make sense.? Thank you.

 

[Adam De Lay]

Not sure what model MultiPlus you have, but on my MP2 5kVa inverter, all the ground connections are bonded together (including the ground stud on the case). You would just have to get a single ground connection to the inverter.

Since it's supposed to be a test setup, my thought would be if you have to run a second line to get a ground to the inverter anyways, wouldn't it be easier to just run a single line to a known grounded outlet?

 

[time2roll]

Also I pulled the outlet - one Hot & one neutral wire only

Should have pulled a ground also. Easiest to have them pulled along the same path or conduit.

 

[timselectric]

Older houses don't have grounded circuits.
For a temporary setup, you can connect to the service mast as described. (Make sure that you get a good connection)
When you set it up permanently. I assume that you will run new wiring and connect it properly.

 

[time2roll]

I have a vintage 1964 house that had many 2 prong outlets. The ground wire was actually behind the box and I brought it in to connect to grounded outlets. Switched outlets had no such ground.

The point is eventually I would plan to pull grounds to all outlets but that will be another day.

 

[John.DS99]

Thanks,

Mine is the MP2 5kVa. If I do attach a ground wire it only needs to go to the ground on the box and not worry about the AC inpput?

I'm not sure how to prove an outlet is grounded. I did test an outlet in the kitchen. I looked for continuity between the neutral and ground it read about 1 Ohm. Is that proof? If so I will check all the other outlets and see. Still that one is much further away than the meter pole.

When you say pull the ground do you mean pull the outlet wire out so far I might see the ground wire?

I have no idea how to pull grounds through a house. It sounds expensive. the walls are stucco and not easy to open up. I will have to study that. I am also thinking about replacing all of the outlets in the house with solar outlets. That is I build my own solar outlet in an old land line box and I don't wire it through walls except in penetrations that I make. Maybe this is the hard way.

I have never understood grounding of AC lines. My work with electricity has been DC toys for cars, arduinos, custom lights, etc.

Outlet - my eyes are not that great but I didn't see a green wire in there, but I can try harder.

Below that is the rat's nest that show the wire at the bottom of the panel. The left yellow arrow points to the line on the outlet in question and the right arrow (fatter) points to the clipped off ground wire. I will try again to see if there is access to the ground wire, It could be clipped anywhere.

If I find it I will have fixed a whole outlet, at least the one that's important to me.

Thanks again.

 

[Adam De Lay]

Mine is the MP2 5kVa. If I do attach a ground wire it only needs to go to the ground on the box and not worry about the AC inpput?

Either one will work.

I'm not sure how to prove an outlet is grounded.

You could use something like this: https://a.co/d/iXc6vv0

Fixing old wiring is never fun. Good luck!

 

[John.DS99]

Thank you, I'm glad this forum is here.

 

[John.DS99]

OK, I will go one more. I couldn't find any other ground on my Sig Solar 6500EX other than the AC input from utility. Is that correct? Or is there somewhere else?

 

[Adam De Lay]

OK, I will go one more. I couldn't find any other ground on my Sig Solar 6500EX other than the AC input from utility. Is that correct? Or is there somewhere else?

There’s a ground on the AC In and AC Out, but they’re both tied together.

 

[time2roll]

Does not appear to have a separate chassis ground. Looks intended to be connected to an existing system with a ground or needs a ground rod.

Manual p14:

WARNING: To avoid potential electrical shock, this unit must be connected to a permanent grounded wiring system or a stand alone grounding rod.

 

[John.DS99]

Thanks all, very much appreciated.

 

[cdsolar]

Either one will work.


You could use something like this: https://a.co/d/iXc6vv0

Fixing old wiring is never fun. Good luck!

FYI, these are also available at your local HD or Lowe's ...

 

[John.DS99]

Thanks all, I bought one of the Klein units and went around the house. Every outlet was two pronged, so the outcome for those was - I can't even insert the Klein device. Automatic fail.

Then I set it somewhere and can't find it anymore. No idea, that was 2 days ago.

I did find one outlet that was grounded in my kitchen. It was a gfci beside the kitchen sink. One ground in the entire freaking house.

I'm proud to say that all of the solar power outlets that I installed tested out OK on the Klein tool. I might examine some of my outlets to see if there is an access to the ground wire so that I might be able to connect to that wire inside of the main panel and establish a ground.