Inverter to house problem

Timber wind

We have been using solar and generator power for several years now. We are just completing an off grid home and passed final electrical inspection. Everything done to code

Connected the batteries to the house via the inverter and blew the fuses in the inverter. Pop and electrical smell

We can run the house off our 3000 watt honda generator by itself

If the inverter is not plugged into the house then the batteries will run anything

We have not tried to charge the batteries (just in case it matters) but they are fully charged

We have tried a second inverter to house and although it didn't blow we get slow flickering of our fluorescent lights
And the fault light comes on on the inverter

We have tried disconnecting the house ground in case there was a conflict


Should the inverter be grounded to the grounding lug? We didn't do this on our other building and it wasn't an issue


Any other ideas as to what may be causing this inverter to house problem?

Just to advise. House was professionally wired

Thank you for any ideas

Timber wind

Cariboocoot

Re: Inverter to house problem

Welcome to the forum.

You need to supply us with further details, especially just what inverter it is. There are a wide variety of them and some, such as the MSW type, will not work well with 'standard' household wiring. Most specifically they can not tolerate the neutral-ground bond that code wiring requires. it sounds very much like this is what happened.

Another possibility is AC Voltage incompatibility; mis-wiring a 120 VAC inverter to a 240 VAC service can result in some unpleasant sparks and smoke.

Vic

Re: Inverter to house problem

Hi Timber,

We always ask for additional information on systems.

Do you know if the inverter that is causing fuses to blow is an MSW type? Usually, such inverters will not tolerate a bond between the AC output cold lead and the panel neutral -- the output usually needs to float. There could easily be a bond between the neutral and system ground in the Main panel of the house.

What is the brand of the Inverter, and its model number?

Just guessing. Vic

Timber wind

Re: Inverter to house problem

This is making sense. Will check it out and get back to you. Thank you

westbranch

Re: Inverter to house problem

Just a thought, do you have any GFCI's?, you should if it is up to code... If so did they all check out when hooked up to the generator? might be some mixed up wiring...

My money is on the MSW grounding issue though.

mike95490

Re: Inverter to house problem

Works fine on generator
House wired by pro, who would have bonded neutral to ground in the main panel, and to a ground rod

And a mod-sine inverter would be expected to blow/fuse/fry with a bonded neutral in the panel.


48v DC system ? Battery neg grounded ? PV panels frame grounded? PV - grounded ?
What charge controller? What inverter? What sort of batteries ?

waynefromnscanada

Re: Inverter to house problem

Agree with the others, I expect the problem is an MSW inverter that would have worked fine - - - until connected to the house wiring that has it's neutral bonded to ground.

zoneblue

Re: Inverter to house problem

The other probable cause is a cheap chinese sine wave inverter. The out of the box failure rate is very very high for those. I know a guy that was selling one particular brand here for a while and he reckoned fully 20% were returned inside a week.

Make sure you have quality gear.