Open ground question.

Chris11 · July 2020

We had our family get together last weekend....all went well. My grandie told me that about 7 am she plugged in her phone to charge it and it wouldn't charge. I dismissed it since she's 12 and I thought goofy but wonderful. The next day my son, a little older and wiser, said he experienced the same thing. I plugged in my tester to the 110 outlet which they were using and it said open ground. I looked into the 110 breaker box that feeds where they were plugging in and found the ground wire was disconnected.

I now have 8 GC batts and that particular night not much was being drawn so I don't understand why the inverter must have shut off (not low volts in other words) unless the open ground on the 110 side of the inverter onto the 110 breaker box had something to do with it.

Question. Did the open ground have anything to do with the shutdown of the inverter?

Ask questions since I didn't give a lot of information for you.

Thanks in advance. Chris

BB. · July 2020

In general, an open (disconnected) ground wire should not cause a problem (other than a possible safety issue with 3 prong loads--But that is another discussion).

My guess is there is something else wrong in the wiring, such as a miss-wired outlet (Black/Red wire to brass colored screw, white wire to silver screw, and green/green-yellow/bare copper wire to green ground screw--North American typical color codes).

If the "Hot" and "Neutral" connections were reversed, and a miss-wired load with 3 prong plug was connected (i.e., both "neutral" and "ground" were connected in the load--not typical, or possibly a surge protected power strip/etc.), it could short out the AC power. By lifting the ground wire, they opened the circuit and kept the short from happening (tripping breaker, shutting down the AC inverter).

So--The first thing I would try is reconnecting your ground wire (in the main panel?) and check all outlets for proper connections (no reversed Hot/Neutral connections, indicator light from Hot to Ground).

Just a very wild guess--When you run across something like this (a wire disconnected that you know nothing about)--There is a good chance that somebody was trying to make a quick and dirty fix.

I have seen really weird stuff too... In an old apartment building in San Francisco--Originally plumbed for Gas Lighting (before electricity)--There was a short between the electrical wiring and the gas pipe. The electrician had to take every fixture/box apart to find that one.

-Bill

Chris11 · July 2020

Thanks Bill. I actually did plug my little tester into each outlet originally with no problem shown. The ground wire had somehow slipped out of the connector, I assume the idiot installer ( me ) didn't tighten it correctly and vibration did the disconnecting.

I'm at a loss too as to why everything is working well but the inverter isn't working at 7 am. I have no idea at what time it shuts off or even if it does it every night or not. And I never reset it .... it apparently just started to work again by itself.

The ground wire is now reconnected but we'll have to wait until someone tries using the power that early in the morning, keeping in mind it's a vacation place and I'm not there all the time.

Thanks again, Chris

mike95490 · July 2020

0The inverter shutting down early in the morning, generally means the batteries are low.

BB. · July 2020

Check the DC bus voltage at the input of the inverter.

Depending on the battery bank voltage and specific inverter configuration, generally 10.5 volts is battery cutoff, and many inverters will wait until ~12.7 volts is present (battery charging again)--On a 12 volt bus--2x for 24 volts, and 4x for 48 volt bus.

Depending on what else may be going on--Generator running/charging, relatively full battery bank hit with >~15-16+ volts and hitting high battery shutdown limit in the morning (suflated battery, charge controller a bit "out of control", bad electrical connection somewhere in the DC bus)...

-Bill

Chris11 · July 2020

Mike.. I didn't check them overnight I have 4 new GC batts in series, and in parralel the 4 old ones which still have juju in them, That particular night virtually nothing was on...some nights my son in law uses his pap , no not the smear type, but that night he wasn't there so there was nutting sucking the juju.

Bill...I'd like to but as I said it was one of the two weekends per year that my family is there, and they do follow my instructions that that I got from you smart people regarding conservation. At times I wish hadn't told then that since with the addition of the four new and four old batts there is zero problem keeping the few lights lit.

Today was 98 degrees which has nothing to do with the overnight temp of 2 weeks ago, but my typing fingers aren't sore yet. Oops there they go, now they are.

Thanks guys, I'll let you know if I ever find out what caused this problem.

Open ground question.

Comments

Categories