Inverter or granny charger?

[robbymax]

My house has a fairly large solar system with a battery bank that allows me to be off grid most of the time between March and October one of the characteristics of the studer inverter puts out a voltage on the negative that doesn't seem to bother anything but one thing I have just noticed when I'm on inverter power my granny charger won't work the orange light power light it's blinking and the car will not charge switch over to grid no blinking light and the car charges normally which is not so good because I wanted to start using any excess over and above a full battery bank I could put into my electric car now do I have a inverter problem or a granny charger problem?.

 

[siteguru]

Sorry but that's really hard to comprehend ... some punctuation may help.

 

[Jomarkh]

It could be an earthing issue that the granny EVSE is seeing

 

[robbymax]

My house has a fairly large solar system, with a battery bank that allows me to be off grid most of the time, the studer inverter puts out a voltage on the neutral, that doesn't seem to bother anything, one thing I have noticed when I'm on inverter power my granny charger won't work, the orange light power light it's blinking and the granny charger instructions is saying that there is an earth fault and the car will not charge, switch over to grid and no blinking solid Orange and the car charges normally, that is not so good because I wanted to start using any excess above a full battery bank I could put into my electric car, now do I have a inverter problem or a granny charger problem?

There is that better now can you help me?

 

[robbymax]

It could be an earthing issue that the granny EVSE is seeing

thank you for the reply I thought it might be a socket problem so I tried several sockets but they all have the same problem

 

[5teep]

EV chargers are very safety orientated and will not work if there is anything anomalous in their pre-charge checks. I have no idea if the voltage you are getting on the negative line is a bad thing but it is probably better to get a professional's advice rather than guys like us.

 

[siteguru]

There is that better now can you help me

It looks almost exactly the same except for the addition of a few commas. But at least it's slightly easier to read.

Sorry but I can't add to what's already been said- it's almost certainly a floating earth issue, as the granny charge lead probably expects the Neutral to be very close to the Earth - i.e. little to no voltage difference.

 

[Coulomb]

Some inverters automatically connect AC-out neutral to earth when in battery mode, and remove this connection when using the AC-in. Usually AC-in will have its own connection to earth, and you must not have more than one such connection.

It sounds like you have an inverter that doesn't have this feature, or maybe it's disabled either through a setting or by leaving out a screw in a special position.

If you're handy with electrics, you might be able to find a solution in the inverter's manual, or on a forum. You may need an external device to make it work. The granny "charger" is telling you an important safety message: your inverter is not as safe as it could and should be. Residual current devices won't save you from a shock in some circumstances until this issue is sorted.

 

[decrep]

@robbymax ,when you write "negative" do you mean "neutral"?

AC has no negative and positive.
When you say negative, sounds like you are talking about a DC output from the inverter.
Or do you mean there's actually a negative DC voltage coming out of the neutral connection?

I don't know the British system, but I don't think the neutral should have a voltage to earth, either DC or AC

 

[dannyg3081]

I do have two solar energy systems, one of 5.5 kW off grid and the other one of 3 kW on grid and I never had a problem charging my car on or off grid. I think your problem may be related to grounding, if there is a problem or insufficient grounding, that might be a problem. You should have a grounding under 3 ohms, mine is 1.8 ohms. Wish you all the best.

 

[T1 Terry]

I suspect you will need to add a quality inverter to your solar storage battery, dedicated to charging the EV. The inverter you are trying to connect with at the moment is using a floating earth, neither AC output is tied to the earth line, so there is no active and neutral, just line 1 and line 2 ...... the granny charger is looking for one of the AC lines to be tied to the earth line, without that, it thinks you have a broken earth cable and the system would be considered dangerous because it can't earth the EV to prevent an electric shock if there was a problem with the EV.

Trying to tie one leg of the inverter's AC output to the earth circuit will probably upset the export to the grid, a separate inverter with an automatic earth/neutral link, like a Victron inverter, will solve the problem and allow you to use the solar energy you have stored in the battery as well as any solar energy the system is sending to the battery rather than the grid ..... so it depends if the energy you buy from the grid is cheaper or dearer than what you are paid for the energy you export to the grid ....

T1 Terry

 

[Kay]

My house has a fairly large solar system with a battery bank that allows me to be off grid most of the time between March and October one of the characteristics of the studer inverter puts out a voltage on the negative that doesn't seem to bother anything but one thing I have just noticed when I'm on inverter power my granny charger won't work the orange light power light it's blinking and the car will not charge switch over to grid no blinking light and the car charges normally which is not so good because I wanted to start using any excess over and above a full battery bank I could put into my electric car now do I have a inverter problem or a granny charger problem?.

We have a Zappi charger. It gives the option of taking solar only (panels first, then battery) or a mix of solar and grid or just grid. You can see exactly what's being used from the mobile app.

 

[robbymax]

I do have two solar systems, one of 5.5 kw off grid and the other one of 3 kw on grid and I never had a problem charging my car on or off grid. I think your problem may be related to grounding, if there is a problem or insufficient grounding, that might be a problem. You should have a grounding under 3 ohmi, mine is 1.8 ohmi. Wish you all the best.

We have a Zappi charger. It gives the option of taking solar only (panels first, then battery) or a mix of solar and grid or just grid. You can see exactly what's being used from the mobile app.

I suspect you will need to add a quality inverter to your solar storage battery, dedicated to charging the EV. The inverter you are trying to connect with at the moment is using a floating earth, neither AC output is tied to the earth line, so there is no active and neutral, just line 1 and line 2 ...... the granny charger is looking for one of the AC lines to be tied to the earth line, without that, it thinks you have a broken earth cable and the system would be considered dangerous because it can't earth the EV to prevent an electric shock if there was a problem with the EV.

Trying to tie one leg of the inverter's AC output to the earth circuit will probably upset the export to the grid, a separate inverter with an automatic earth/neutral link, like a Victron inverter, will solve the problem and allow you to use the solar energy you have stored in the battery as well as any solar energy the system is sending to the battery rather than the grid ..... so it depends if the energy you buy from the grid is cheaper or dearer than what you are paid for the energy you export to the grid ....

T1 Terry

Thank you Terry I don't have a system that exports to the grid I use it all and store it all no point in selling to the grid they don't want to give you anything what I need to sort out if it is a problem is the Earth so I will have a word with studer the inverter manufacturers and see if they can suggest anything

 

[T1 Terry]

Probably an MEN link will sort the problems, as well as make all the RCDs on the system actually function ..... with a floating system, if you become tangled up between line 1 and line 2, you will be seen as an appliance to powered up ..... not a good thing
There are devices called RVD safety switches available, they look for and voltage on the earth circuit where an RCD is looking to see if the current flow is the same on the active and neutral if you divert the current from the active, through your body, via the earth circuit, the imbalance is sensed and the circuit opened .... so fast you don't really feel the bite ..... if you are lucky and the RCD is actually working properly

T1 Terry