Voltage(52v) showing between earth and neutral on output from inverter

K

ketoneenergies

New member
Joined
Oct 22, 2018
Messages
28
my setup is 5kva inverter with 48v battery and utility(230v) input . when inverter bypass utility to load, voltage between earth and neutral is negligible. But when inverter powers load from battery , earth and neutral showing voltage of 52v and earth to live is 178v, live to neutral is 230v. Battery voltage is around 52v~54v. Any reason and solution?
 
Which inverter do you have?
 
Axpert off-grid
 

Attachments

  • 12.jpg
    12.jpg
    899.4 KB · Views: 407
ketoneenergies said:
my setup is 5kva inverter with 48v battery and utility(230v) input . when inverter bypass utility to load, voltage between earth and neutral is negligible. But when inverter powers load from battery , earth and neutral showing voltage of 52v and earth to live is 178v, live to neutral is 230v. Battery voltage is around 52v~54v. Any reason and solution?
Click to expand...

I had the same thing on my 5048. The reason is, that Neutral-Earth is not bonded inside the inverter itself. You have to bond Neutral to Earth within your first Load center after the inverter, where it is feeding in. But before you tighten the screws, just touch Earth wire to Neutral first, and see if the inverter does give you an Error Code or not :)

My Must 5048HM did it without a problem. I only found it out myself, because I was permanently electrocuting myself when I was working on my garden lights, where I only have a single pole breaker on phase, and when I was touching Neutral it always gave me a drizzle. hehe
 
Last edited:
Roland W said:
I had the same thing on my 5048. The reason is, that Neutral-Earth is not bonded inside the inverter itself. You have to bond Neutral to Earth within your first Load center after the inverter, where it is feeding in. But before you tighten the screws, just touch Earth wire to Neutral first, and see if the inverter does give you an Error Code or not :)

My Must 5048HM did it without a problem. I only found it out myself, because I was permanently electrocuting myself when I was working on my garden lights, where I only have a single pole breaker on phase, and when I was touching Neutral it always gave me a drizzle. hehe
Click to expand...
Seems to me that the OP is in an area where neutral and ground are not supposed to bonded in the main panel. Could be wrong. Isn’t neutral and ground only bonded in a splitphase main panel?
 
Cheap 4-life said:
Seems to me that the OP is in an area where neutral and ground are not supposed to bonded in the main panel. Could be wrong. Isn’t neutral and ground only bonded in a splitphase main panel?
Click to expand...

No, single phase, split phase 3 phase any of those, but it shall be right after the point of generation. Bonding is providing the Zero-reference to the inverter. Without it, the inverter will still output a sine wave with correct parameters, but it will be most likely shifted away from Ground as you can see in this example.
 
I went down a similar path to fix the ground and neutral bond issue when off-grid in my RV. I used a Zettler AZ2280-1C-120A relay to bond the ground and neutral only when off-grid. If I'm grid connected my main panel has the bond. My circuit analyzer no longer reads open ground when on battery power only.
 

Attachments

  • IMG_20200921_142150.jpg
    IMG_20200921_142150.jpg
    116.7 KB · Views: 544
MilkMan said:
I went down a similar path to fix the ground and neutral bond issue when off-grid in my RV. I used a Zettler AZ2280-1C-120A relay to bond the ground and neutral only when off-grid. If I'm grid connected my main panel has the bond. My circuit analyzer no longer reads open ground when on battery power only.
Click to expand...

This is the key here. You can't just hard-wire the N+G bond because then when you're running on utility, your ground wire between mains panel and inverter becomes a current-carrying conductor (very bad). The N+G bond after inverter can only happen when running in off-grid mode (utility disconnected).

If unsure, I highly suggest contacting an electrician to evaluate / make a recommendation.
 
MilkMan said:
I went down a similar path to fix the ground and neutral bond issue when off-grid in my RV. I used a Zettler AZ2280-1C-120A relay to bond the ground and neutral only when off-grid. If I'm grid connected my main panel has the bond. My circuit analyzer no longer reads open ground when on battery power only.
Click to expand...
Can you give the circuit diagram of the connection because wiring is not clear from the picture.
 
LithiumSolar said:
This is the key here. You can't just hard-wire the N+G bond because then when you're running on utility, your ground wire between mains panel and inverter becomes a current-carrying conductor (very bad). The N+G bond after inverter can only happen when running in off-grid mode (utility disconnected).

If unsure, I highly suggest contacting an electrician to evaluate / make a recommendation.
Click to expand...

I was thinking of using a similar relay operated system to provide the neutral/ground bond on my inverter when operating off-grid. I believe this is how Victron does in internally in their higher end inverters.

On a side note... Every time I talk to an electrician (at least online) they go berserk when the DIY conversation comes up. Apparently none of us non-licensed types are qualified, and even when I proposed a good interlocked automatic transfer switch design with failsafe using brand name contactors, I was scolded, told I would be killing linemen, and gave me the liability talk.

To be honest it makes the AC side of the system a bit off-putting, but all I am trying to do is just follow code. Then again, maybe he has a point. I see ATS units that look nowhere as nice as what I am building, but its UL listed and made by someone else so none of it has anything to do with me. Then again, making my own using contactors looks pretty industrial and overbuilt.
 
I know its a bit off-track from ground, but I too use ATS(s) in my off-grid system. I use Go-Power ETL 120v@30a (single mechanical relay) and Progressive Dynamics ETL 240v@50 mechanically interlocked relays for shore/generator (e.g. grid/inverter). These are both ETL (i.e. as good as UL) and are commonly used for grid / generator purposes.

As far as I can tell - I'm being as responsible. Mechanical relays / interconnect relays are just physically not likely to connect inverter to grid inadvertently and they are ETL and they are being used as they are designed.
 
When i bond earth and neutral at inverter out, voltage is showing zero, but when inverter bypass utility power, rccb is tripping because current is leaking from utility's neutral to earth. I tried connecting relay. But relay is not switching because the voltage 52v is AC not DC. What should I do?😕
 
ketoneenergies said:
When i bond earth and neutral at inverter out, voltage is showing zero, but when inverter bypass utility power, rccb is tripping because current is leaking from utility's neutral to earth. I tried connecting relay. But relay is not switching because the voltage 52v is AC not DC. What should I do?😕
Click to expand...

You cannot bond behind a RCCB. The Inverter is considered same level as you grid input. You must treat it that way. That's why you might have to use a transfer switch. One input is Grid other is Inverter. Output goes to the load panel, and there you bond (not at the Inverter terminal).
 
You must log in or register to reply here.
Back
Top