Hello, I wonder if somebody could help me. I purchased an all in one H1 inverter and battery in March 2022. That’s the one in the cabinet. The batteries have version c on them. It was all set up and working by April, 22 with 8 solar panels with output of 4.5kw max. I also set it up that it would have an eps output. At that time I could not get anybody to do the installation so I did it myself. I found it reasonable easy. I did a separate wiring for the eps output through a consumer unit to three outlets in the house. This was incase there was any power outputs. The set the internal relay to on so the eps output plugs were always live and feeding these sockets. Small night lights were put in the sockets. It was all tested and working fine. I had the assistance of an electrician who checked it all over. These outputs basically were to power lights incase of power outage. The voltage was checked and found to be 240 volts with no earthing faults.
I also grounded the cabinet to the main earth of the house in the fuse box as well as fitting an external grounding rod. The mains input to the unit was supplied from a separate breaker box in the main consumer cabinet running 10mm cable to the cabinet in my Garage.
All has worked as it should with the batteries being either charged by the solar panels or cheap rate electricity overnight. From about mid Feb till October I don’t use if any very much electricity from the grid. The system also provides 300 litre of hot water each day. So don’t use much gas between those months either. I also have another set of 24 solar panels which were fitted in 2010 and are still working fine. No battery system on these just a feed in tariff.
As you will be aware the last big storm knocked out the Electricity supply in many areas including where I live. For the very first time the EPS kept electricity going in the house so we had lights and wifi for phone coverage as there is a poor signal.
Anyway I noticed that when one of the lights was switched on that the wifi router kept restarting. I have a plug that you can check circuits with and when I plunger it in it was showing that the voltage was wavering around 180 volts and the neutral to earth was showing 40volts. The lights still worked fine.
A few days later I have checked the settings on the cabinet and when the cabinet is connected to the grid the I used the plug and checked a socket in that garage just off the cabinet connected to EPS output 6mm cable. It’s was showing fine. 240 volts with no earth leakage. However when I switched off the grid input. The EPS output dropped to 180 volts and N to E 40 volts as per the readings I got when the powers was cut. I also checked the sockets in the house and same result.
I checked the settings for EPS in the cabinet and it was set for 220 volts out at 50hz. I also checked the other readings and on the cabinet screen it was showing 220 volts 50hz. Yet that is not what was coming out of the EPS output.
I rewired the plug that fits into the EPS output at the rear of the cabinet incase it was faulty but after connecting it to a make shift socket it was still showing 180 volts etc as above.
I have tried different settings but of the grid is disconnected then the output via the EPS is 180 volts etc. Once you connect it to the grid the EPS goes back to 220 volts.
There is something not correct in the cabinet somewhere as according the the spec it should put out if set to, 240 volts 50 hz.
Spent a few days on it and still get those incorrect readings showing something is not right.
Can anybody shed some light on what may be wrong or what I need to do to sort it?
As stated if the cabinet is powered from grid, ie grid cable connected, the EPS readings are fine. If grid disconnected then the 180 volts is what is coming out of the EPS supplied by the batteries. Don’t seem to see anything wrong with the batteries. When the settings and system are checked they seem all fine. I have not updated any of the Firmware since I got it as it’s always worked fine. Not had occasion to not have grid connection before.
I have pics of readings etc. The batteries and BMS will be V1 I would say. The batteries have version C on them.
Thank you.
Problem with EPS. Low output voltage and loss to earth
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The problem I think is that whilst you have an earth rod which provides an earth when the grid is disconnected, what you don’t have is a bonding relay that connects PE>N.
Your incoming grid will make that connection externally to your house (usually in your meter cupboard with TNCS where your DNO cutoff is).
As soon as you loose your connection to the grid you lose that neutral to earth bond and that is why you have a floating neutral - typically in this situation you would use a single pole contactor to bond your EPS load N to Earth when the grid is disconnected.
Your incoming grid will make that connection externally to your house (usually in your meter cupboard with TNCS where your DNO cutoff is).
As soon as you loose your connection to the grid you lose that neutral to earth bond and that is why you have a floating neutral - typically in this situation you would use a single pole contactor to bond your EPS load N to Earth when the grid is disconnected.
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- Joined: Thu Oct 13, 2022 7:21 pm
Only the latest H1 G2 inverters have automatic PE-N bonding on EPS circuits.
If you have a good electrician, this would do it a Hager ESC226 25A NC contactor where the contacts are held open by grid power (either on a din rail or in a single way din enclosure).
If you have a good electrician, this would do it a Hager ESC226 25A NC contactor where the contacts are held open by grid power (either on a din rail or in a single way din enclosure).
Hi, Just to let you know. All wired up this morning and working perfectly. Thank you very much for your help. Take care. Graham.
PS. I take it the UPS option won’t work properly when connected to the grid and give the floating values again?. Take care.
PS. I take it the UPS option won’t work properly when connected to the grid and give the floating values again?. Take care.
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- Joined: Thu Oct 13, 2022 7:21 pm
ok great,Skip62 wrote: Sat Feb 01, 2025 11:18 am Hi, Just to let you know. All wired up this morning and working perfectly. Thank you very much for your help. Take care. Graham.
PS. I take it the UPS option won’t work properly when connected to the grid and give the floating values again?. Take care.
On the UPS option that will effectively pass through L & N to the EPS socket and the relay should be held open as the grid is available - the PE-N bonding will be made at the DNO cutoff so the grid Neutral should be bonded (as should the EPS Neutral if it is passed through). TBH I haven't tested that but I would have expected it to be ok.