48V Charger

[sharpener]

Cheers sharpener .

Perhaps not essentlal if you are TT, maybe converting to TT would be simpler?

It is something I have thought of. The house is on 3m deep soil with granite below. It isn't terribly conductive especially when dry. We had 3x2m copper stakes put in for the Quattro but only achieved about 120 Ω. I was wondering if those discs with conductive concrete might be a way to go.

120 ohms is OK, even with a 100mA RCD. IIRC the requirement for an ESS is <200 ohms for "stability", and voltage rise <50V at the trip current which with 100mA would be 12V. Why would it need to be better than that for the genny?

Presumably you are connecting the genny to the ACIn 2 as that is what the distinguishes the Quattro from the Multiplus. As I only have the latter I don't know what happens with your internal N-E link relay when the grid fails but the genny input is active. Or whether the ACOut 2 is enabled in this scenario but I think it can be using Assistants. My thinking upthread was that if ACOut 2 is connected to the coil of a n/c contactor this could make an external N-E link whenever it switches off.

The gen is on AC1 as that is the logic used in the system operation. If either AC input is live then the default behaviour is top open the ground relay. The assumption is that a neutral to earth connection is provided elsewhere. So in normal operations if I lose the grid then the neutral earth connection is made in the unit. However one is still required if I connect the generator. There is a way to override this behaviour

If you can override it for the genny input that will solve your earth bonding problem surely?

Have you looked to see what Victron Wiring Unlimited has to say?

This post on the Victron community has the following

Another downside with generators operating at the AC-input is, that the network type plays an important role. Most smaller gensets are isolated IT type gensets. It is not legally allowed to use them at a house installation by most local laws. You have to use a genset equipped with RCD, those are not the entry level price ones.

Further down Markus then mentions that the easiest solution is just to add a DC charger and then all issues go away. I am still tempted to do this as I am not intending to have the generator sit there waiting for a load. It's incredibly inefficient doing that.

I am not sure what territory Markus is talking about here, some of that discussion centres on Italy which sems to be quite restrictive. For the UK I think there is a permissible earthing scheme in the IEE link you provided and at a practical level I think bonding the genny frame to your earth rod and making sure there is always a neutral link somewhere that does not bypass any of the earth leakage protection is as good as you need.

Most of what Markus says is about getting the Quattro to accept the AC quality of the genny output, and I was surprised to read some of the limitations given that the Quattro is aimed at the market for dual grid/genny supply. So maybe using it to supply the DC side is the best solution after all. He must have money to burn if he is using a Multiplus just for that.

I had a house changeover in the past done by an electrician and never got told about which type of generator I could use. Presumably as the victron disconnects from the grid it is ok to use? If the N-E is combined then all the RCDs are downstream of that connection so should presumably function.

What did the electrician do about providing an earth connection for the genny, and does it comply with the IEE paper?

[Andy]

Yes, you kind of make a mortar with it.

You could also get bare copper tape, and bury this in a trench, tie it to the rod too and run a 16mm2 earth to the equipment.

That might be an easier option as I have a JCB coming soon for something else. I've read 60 cm depth but is it a case of the deeper the better? In a rubbish area what sort of length might you put in?

[AGT]

What ever you can afford, probably allow £20 a metre for 25x3 mm bare copper tape

https://www.electrical-installation.org ... electrodes

[Andy]

If you can override it for the genny input that will solve your earth bonding problem surely?

Unfortunately it seems like the override is only for the state in which the neither of the inputs are connected.

What did the electrician do about providing an earth connection for the genny, and does it comply with the IEE paper?

I just reread my paragraph and it isn't clear. I don't intend to use that old change over. In the past it was just a case of changing the relay and then I could run the water and lights. I wasn't sure about earthing as I didn't pay much attention back then. What I was trying to say is that as long as I have a NE connection before the RCD then they should work?

Most of what Markus says is about getting the Quattro to accept the AC quality of the genny output, and I was surprised to read some of the limitations given that the Quattro is aimed at the market for dual grid/genny supply. So maybe using it to supply the DC side is the best solution after all. He must have money to burn if he is using a Multiplus just for that.

I think they have improved the situation with generators in the last few firmware updates. Since that was written you can now select a generator with/without LOM for an input and this makes it easier to get it to pair. I managed to get the generator to sync up correctly without LOM yesterday so that is all good. The only thing that made things slightly unstable was bringing the Solaredge back in the mix on the AC side. In reality if there is sunshine then I won't be using the generator so its no too much of a problem.

I'll get someone in to finish the wiring and get the tests done. I didn't really want to pay if it was never going to work. Thanks for all your input.

[openspaceman]

What ever you can afford, probably allow £20 a metre for 25x3 mm bare copper tape

https://www.electrical-installation.org ... electrodes

What is wrong with cleaning and flattening some old copper pipe and soldering an earth wire to it then burying it?

[openspaceman]

So maybe using it to supply the DC side is the best solution after all.

This is what I am aiming for, to achieve grid independence. Won't there be less losses if a permanent magnet alternator just outputs DC via a rectifier and feeds a charger for the existing battery rather than have an extra conversion to AC? Then it can run asynchronously with no need to modulate power.

As long as the inverter can run islanded and keep the panels working so there is some solar input

The inverters not recognising the output of my generator is what is wrong with my standby system, so I lost Solar and battery power during a power cut.

[Andy]

What ever you can afford, probably allow £20 a metre for 25x3 mm bare copper tape

https://www.electrical-installation.org ... electrodes

What is wrong with cleaning and flattening some old copper pipe and soldering an earth wire to it then burying it?

Now I’m regretting throwing away all the pipe work from the renovations over the years

[sharpener]

So maybe using it to supply the DC side is the best solution after all.

This is what I am aiming for, to achieve grid independence. Won't there be less losses if a permanent magnet alternator just outputs DC via a rectifier and feeds a charger for the existing battery rather than have an extra conversion to AC? Then it can run asynchronously with no need to modulate power.

As long as the inverter can run islanded and keep the panels working so there is some solar input

The inverters not recognising the output of my generator is what is wrong with my standby system, so I lost Solar and battery power during a power cut.

Yes, the specs are quite tight as frequency is used as the control input, so I can understand losing the PV but why did you not have battery power?

[Andy]

This is what I am aiming for, to achieve grid independence. Won't there be less losses if a permanent magnet alternator just outputs DC via a rectifier and feeds a charger for the existing battery rather than have an extra conversion to AC? Then it can run asynchronously with no need to modulate power.

Are you building one yourself?

[openspaceman]

So maybe using it to supply the DC side is the best solution after all.

This is what I am aiming for, to achieve grid independence. Won't there be less losses if a permanent magnet alternator just outputs DC via a rectifier and feeds a charger for the existing battery rather than have an extra conversion to AC? Then it can run asynchronously with no need to modulate power.

As long as the inverter can run islanded and keep the panels working so there is some solar input

The inverters not recognising the output of my generator is what is wrong with my standby system, so I lost Solar and battery power during a power cut.

Yes, the specs are quite tight as frequency is used as the control input, so I can understand losing the PV but why did you not have battery power?

My battery is ac coupled so neither the PV inverter nor the battery inverter recognised the generator but it did serve the house as it connects by a changeover switch.