After charging batteries from Genset (3 phase Genset to AC Input ) in 3 phase OFF-GRID system, the moment transfer occurs from Genset back to Victron, main home panel RCD trips.
This just started happening since we bonded the neutral at the generator to ground, which wasn’t before.
There is no other neutral to ground bond except the ground relay in the Victron which only works when the Victron is inverting off battery.
The ground to neutral voltage is 3 when using generator.
Ground to neutral voltage is less than 1 when victron is inverting.
When the generator had a floating neutral, there was no such tripping of RCD on AC Output when switching back to Victron.
Neutral to ground voltage used to be 15, when generator was running, and generator did not have neutral bonded to ground. FYI.
Had another electrician check various connections and wiring, and Victron installer come and check, no solution.
The cable from the genset, to the AC In of the Victron has 5 wires, 3 Phase, A Neutral, and a Ground. The neutral is bonded to ground at the generator. The generator has its own ground rod.
Maybe you can make a quick drawing … At the moment I can’t really understand what goes from where to where and where which RCD is located that triggers … may also be due to the gear ratio … the technical side of things can easily fall by the wayside
The cable from the genset, to the AC In of the Victron has 5 wires, 3 Phase, A Neutral, and a Ground. The generator is a 3 phase diesel 50 hz generator.
The RCD tripping is a 3 phase type A 30ma RCD, it is in the main panel inside the residence, which feeds the main loads in the home.
The AC Ouput from the 3 Multiplus is powering this panel.
A quick question … Does the RCD work when the generator is running?
in this case, the earthing relay would normally be open again and the N-PE connection MUST be made at the generator.
What happens if you cut the connection BEFORE switching off the genset?
The RCD works via just the test button, but not sure if that just tests only the actual RCD switch function and not the installation.
If I cut the neutral ground bond at the generator before switching off the genset? Meaning, genset starts with neutral to to ground connection, and then during the running of the genset, disconnect this connection and then turn off the genset?
[The connection between the alternator and the multi must be fused, right?
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Yes it should be, but they didn’t do that its directly wired to generator output. Im installing a new panel this weekend with Switch, Breaker, SPD, and RCD to go between generator output and AC Input of Victron.
Something doesn’t add up here. Could you share the genset model in use? Does the manufacturer require this? They could mention this for a stand-alone setup but if you already have bonding done at main panel, there is no need.
A couple of points from field experience:
0,03A RCD is too small for use with genset or inverters. These are meant to protect end circuits only. Your main RCD should be 0.1 or 0.3, not anything less. Most inverter manufacturers recomend a minimum 0,1A, all less will constantly trip.
Neutral / Ground bonding should never happen in more than one place (main panel)
My question would be whether the RCD also trips if the connection to the generator is ‘hard’ disconnected.
How is the generator switched ON and OFF at the moment …
I have read that only 1 RCD comes after the multis. I suspect a fault due to one of the earthing relays when switching the 3 multis …
I would understand a non-functioning RDC, but tripping would indicate a residual current past the RCD.
Hello! At the moment there is no main RCD, on the victron AC output panel, the installers didn’t include one.
only switch , SPD, and breakers, then branches off to various panels,. The panel in the house (its a large property with various buildings and warehouses and stables), is the only one that trips, its the closest to the victron. It has a 30ma RCD as its protecting loads in the home, with children, etc.
Bonding is at only 1 place, at the same time, as the Victron ground relay , I believe at least, bonds neutral to ground only while the backfeed (ac input) switch is open , and the victron is inverting.
When the backfeed switch is closed (ac input, genset supplying power), the ground relay is open and the bonded neutral from genset is passed through.
One option is to disable Victron ground relay, and disconnect neutral ground bond at genset, and have a fixed bond at the panel where the transfer switch is, and permanently bond there., and see if that fixes the problemo.
Tried to find a manual or wiring diagram for that genset. Only found some four page brochures.
How I see it the bonding should be at your main panel, where your main PE is and the rest doesn’t matter because it all comes down to this one. Maybe in your country the grid regulations are different.
Will give you for example what is required here in Romania. We use a grid system called TN-C, where you have L1 L2 L3 and PEN coming from the grid. In the main panel PEN is bonded to ground and from this point onwards we have L1 L2 L3 N PE. It is forbidden from this point onwards to reunite N and PE, or make another bonding as this will create non optimal paths for electricity in the sistem and you get all sort of weird behaviour. Hence my reasoning that it is the genset bonding at fault here. If you have bonding at main panel, don’t do it at genset again.
I will do that this weekend ,they are still grounded as the grounding bar on multiplus is shared across ac input and both ac outputs .but they don’t share the same ground from Genset cable ,doesn’t hurt to do it .
Greetings close neighbor from Greece we have the same system here except I don’t have any connection whatsoever to the grid .
As I mentioned there only one bond at a time since the multis use a ground relay that opens and breaks the neutral ground bond when the Genset is running . There’s no bond at the main panel further down .
That being said I will see about disabling the ground relay and also disconnecting the Genset bond and making a permanent bond at the transfer switch where all the power sources meet .
And please rewire all your N conductors and never one after the other and then make a ‘knobbed sleeve’ in the duct. All N separately to the connection point. If you ever have damage there, you will get a ‘star point shift’ and terrible damage to the system.
its directly wired to generator output. Im installing a new panel this weekend with Switch, Breaker, SPD, and RCD to go between generator output and AC Input of Victron.