Hi there

Hoping someone can perhaps shed *some* light on what may be going on here.

Background:
While ago I purchased a Synapse 5.0+KRM inverter + 1 x Pylontech 3000C battery. (note: I'm well aware the battery can only supply ~1750W continuous etc.)  

Initially I hooked up the inverter and battery in my home office to test everything and make sure all is well and to temporarily run my office computers etc until we could properly install everything.

In terms of how it was connected:
From the wall plug with surge protection plug top, I supplied electricity to the inverter. Then what used to be plugged into the wall-plug previously (APC BackUPS Pro 900, computers, router etc), was now being plugged into an extension cord + multiplug that was connected to the inverter's output.

All was well and at some point I turned on the aircon in my office (which is NOT on the plug circuit of my office where inverter is connected to). After not too long a time, EL tripped. Thought it was odd - and reset EL and turned it on and sometime later it tripped again. I then reset it once more and switched aircon to fan-only mode, which initially it seems to do the trick but then EL tripped once more and so forth.

Need to point out this only ever happened when there was grid power. This was not the result of a change in grid power either (e.g grid being restored post loadshedding and inverter switching).

The only permanent fix was to remove the earth connection on the inverter supply. Once this was done - never had the issue again. My understanding in the scenario and way it was connected that if the inverter for example briefly switched to battery it would do a earth+neutral bond which could result in EL seeing something weird and then tripping.

 

The trouble is - the inverter has been installed since and *exactly* the same thing occurs now.  It also doesn't trip immediately - it's entirely random far as I can tell. Nothing specific triggers it. Based on my understanding around how it's wired now - I think even if you were to make a permanent E+N Bond on the inverter hypothetically, that it shouldn't trip the EL that covers the 'essential load'  (all the breakers on the far right in pdf doc).

Is there something wrong with this inverter?! Should I return it? How now brown cow?

Thoughts?

hjlinde-db.pdf

14 hours ago, hjlinde said:

From the wall plug with surge protection plug top, I supplied electricity to the inverter.

Presumably, the wall plug has the earth leakage before it, which is the one that is tripping.

The problem is that inverters, especially around the 5 kVA and above size, have substantial EMI currents to earth through special small capacitors. There is usually not enough current from one inverter to trip earth leakage on its own, but in conjunction with other loads (perhaps air conditioners), the earth leakage can build to the point where one transient on the mains (which the small capacitors will happily shunt to earth) and the earth leakage can trip.

If possible, wire the inverter directly to the DB, or provide a special outlet just for the inverter that has no earth leakage behind it. Protect the output of the inverter with earth leakage.

Just an update on this.

Turns out the old M.E.S Earth Leakage breaker was to blame. Based on the wiring and everything it was very bizarre as to why EL would trip so decided to just replace the breaker. Used a Schneider Easy9 series one and problem totally solved.

I had a similar problem and after a while I realized that I shared the neutral bar. Ones I split it all were good