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Problem with off grid 120 volt charging

10K views 28 replies 11 participants last post by  mountainmike47 
#1 ·
I own a 2014 Volt with a factory Voltec 120 volt charger. My charger will only give me a green light (on Voltec) when plugged into the grid. When I try to use it with my 5500 watt gas generator or my 3600 watt Outback off grid inverter I only get a red light. All other appliances will work with the Outback off grid inverter including TV's, computers, printers, refrigerators and any other kind of sensitive electronics. What makes the Voltec charger different? Why will this charger not function when plugged into my inverter? This inverter is not a cheap Made in China item. It's made in the USA and costs $1800. Are there any electrical engineers out there who can explain what's going on?
 
#2 · (Edited)
Look at the tag that came with the EVSE that explains what the various colored lights mean (IOW, RTFM). It will tell you what the issue is when you have a red light. Depending on which light is red you likely have a bad ground or low voltage. The EVSE is sensitive to both.

Also, the car's owner manual has some advice under Electrical Requirements for Battery Charging on charging from portable power generators that you may want to heed. When I see "do not" and "only", well, I would follow the manual considering how much the car costs and how much out-of-pocket liability you have assumed.

One of the advantages the Volt has is it is a dual fuel car. You can run on gasoline, electricity is not a critical necessity as it is for a BEV like a Leaf or SparkEV.
 
#5 ·
Big red flag here: Why in the world would you run a gasoline generator to charge a car that has its own gasoline generator already built in? That's completely counterproductive.

As for the inverter question, I'm assuming it's powered by solar panels and/or a large battery bank that isn't dependent on burning gasoline. In that case, you can do a few simple tests with a multi-meter to narrow down any issues. Hot to Neutral should be between 110 and 125. Ideally, it will be exactly 120. Next, test between Neutral and Ground. Ideally, it will be zero. However, it is not terribly uncommon for a very faint bit of voltage to be present here due to induction along the way to the outlet. I've never seen this reading higher than 2 volts and usually it's 0.5 or less. Test from Hot to Ground too. This should also read 120. Finally, double check that the hot line is wired into the narrow slot on the right side of the outlet, not the slightly taller slot on the left side.
 
#6 ·
Thanks to all who have responded. I need to clarify a few points. I charge my volt with a level 2 charger on a daily basis. What I would like to have is a way of charging the car in an emergency when the grid goes down for an extended period of time. I realize that some folks believe this could never happen so why bother but I would like to know that I could still charge my car using my solar system. Unfortunately most who claim to be charging their Volts off solar panels are doing nothing of the sort. They are charging the car off the grid and then selling power back to the utility. In the event of an extended grid outage their solar panels go to sleep and are basically useless. I have two 3.5kw solar arrays powering two 48volt systems with 4 battery banks consisting of 32 Rolls 6 volt batteries. In the event that the grid is hacked, I can still function to a great extent with my solar system. I was told to upgrade one of my pure sine wave "Made in China" inverters to a "high quality" "Made in USA" Outback inverters. I just finished the installation today and to my disappointment this inverter does not seem to be compatible with the Voltec charger either. I have an excellent ground - a #8 wire running from the inverter ground terminal directly to the ground bar inside the main breaker box. I have a circuit tester with the three lights and everything lights up the way it should when plugged into the inverter. The label on my Voltec only talks about not using an extension chord and to be sure to use a good quality outlet. Nothing about what the red light means on the Voltec. The owners manual only talks about the lights on the dash and nothing on the Voltec. I looked through all my paperwork and cannot find a Charge Cord User Guide and couldn't find one on the internet. Does anyone have a website for that download?
 
#9 ·
I have a circuit tester with the three lights and everything lights up the way it should when plugged into the inverter. The label on my Voltec only talks about not using an extension chord and to be sure to use a good quality outlet. Nothing about what the red light means on the Voltec. The owners manual only talks about the lights on the dash and nothing on the Voltec. I looked through all my paperwork and cannot find a Charge Cord User Guide and couldn't find one on the internet. Does anyone have a website for that download?
The quick reference guide come zip-tied to the cord: http://gm-volt.com/forum/showthread.php?15259-Voltec-120v-and-240v-Hang-Tags

The Volt owners manual, Driving and Operating > Electrical Requirements for Battery Charging (page 9-52):
CAUTION Do not use portable or stationary backup generating equipment to charge the vehicle. This may cause damage to the vehicle's charging system. Only charge the vehicle from utility supplied power.
 
#7 ·
Do you have any other load on the inverter, or just the EVSE plugged in ? Sometimes the power distortion can be smoothed out by a simple resistive load. Can you plug a 60-100 watt plain light bulb in first, then plug in your EVSE ?

Also, if there is no other load, the inverter may be in a sensing/search mode and the EVSE isn't going to detect the right voltage, etc. Again, small resistive load would be worth testing.

Bob
 
#12 ·
Is it the same for neutral to ground?

I have read othat some inverters give 60V per leg instead of 120V and 0V.
I learned it is called balanced or technical power and is popular for the home audio as it reduces noise.

Been trying to get a definitive answer as to how that would work for most items, or if it would cause problems. Only found references to audio equipment.
Guess EVSEs don't like it ;)

My intended use would be the opposite though, pulling energy out of volt to power my house, so not a deal breaker if EVSE doesn't work.
 
#13 ·
Steverino - Thanks, I read that passage in the Owner's Manual. My charger does not have the selector between 8 and 12 amps. It is only 12 amps.

Henry - Is there a solution to not having the neutral to ground bond?

Bob - I connected a receptacle directly to the inverter. The charger is plugged into the receptacle. No other loads on this circuit.

Canehdian - Neutral to ground is zero.
 
#14 ·
Steverino - Thanks, I read that passage in the Owner's Manual. My charger does not have the selector between 8 and 12 amps. It is only 12 amps.
It doesn't matter. There is nothing in the owners manual "do not use a portable power generator" warning that makes an exception for EVSE's that have no amp selector.
 
#15 ·
Most generators have "dirty" power. You need a device called a Line-R to run the power through to filter it. Make sure the generator is grounded to the same ground as your house with a solid core heavy conductor. 8 or 10 gauge minimum.
 
#16 ·
The solution to missing a neutral to ground bond is to bond them. This simply means that the neutral and ground wires are physically connected in the breaker box. It's important for safety that the bond is ONLY made in the circuit breaker box and not at the receptacle. This should have already been done at the time your box was installed. You can test for this already being done by measuring resistance between neutral and ground at the receptacle. It should be very close to zero ohms. Also, you can never have too much grounding. All grounds from both utility power and inverters should be connected together.

I'm a bit concerned about the low voltage measurement from hot to ground. I'm pretty sure that's the reason your EVSE is not working and once the neutral bond is fixed it should start working.
 
#17 ·
The Outback inverter has 3 main inputs. One is the red positive cable coming from the 48 volt battery bank. The second is the black negative cable coming in from the 48 volt battery bank. The third is a ground lug which I ran directly to my main breaker box ground bar using #8 wire. There are 3 outputs. Hot, Neutral and Ground. I installed a small sub panel box containing two 20 amp breakers. I ran #8 black from the inverter output Hot to the center buss bar that the fuses snap onto. I ran white #8 from the inverter neutral to the neutral bar inside the box and ran green ground cable to the ground inside the box. As far as I can tell the neutral and ground are both touching the metal box so I assume they are connected. I then installed the two breakers. Under the panel box I installed 2 boxes with 2 receptacles in each box. Hot/gold screw/black #12 wire into breakers, Neutral/silver screw/white wire into into neutral bar inside sub breaker box and green ground wires from receptacles into ground screw in sub breaker box. Since the ground screw touches the box and the neutral bar touches the box, I would assume that they are "connected." Am I missing something?
 
#21 ·
How carefully prepared was the grounding bar's connection to the actual physical soil/ground beneath your feet? I know from some computer labs that typical rods in different soils may not work well, sometimes more extensive preparation is needed.
 
#27 ·
What you are doing does give you an energy back plan but I would rather use regular gas in the Volt for a short time.

we don't store 90+ gas on our farm just the other types.
 
#28 ·
The magic trick was to create the neutral-ground bond. Apparently all house current has that bond but (most) inverters do not. I'm not sure why they don't provide this in the inverter. As a result you must make this bond to duplicate house current. I have a small sub panel box beneath my Outback inverter which provides current to 4 receptacles. I connected the white/neutral to the green/ground in the sub panel box and now my receptacles all have "house current" which the Voltec charger chord seems to like.
 
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