I searched on this forum as well as on other locations, e.g. Google and the Quattro User Manual, and did not find the answer to my question . I am trying to figure out how to safely wire US 240/120 v 50 amp split phase power to a Victron Quattro 8 kva 230/240 v unit. As background (sorry it is long but want to provide enough context):
I will have a separate 120 v 60 Hz 5 kva Quattro and shore power inlet for my 120 v consumables. So I do NOT need to convert a 240 v source to 120 v.
I am interested in plugging into US 240/120 v 50 amp (4 wire- 2 hots, 1 neutral, 1 ground) shore power to take advantage of the 12,000 wats of power (vs 6,000 w for a single leg of 120 v 30 amp shore power, which I will get on my 120 v Quattro). This power source will go to a 230/240 V (50/60 Hz) 8 kva Quattro. Seems from the user manual like this Quattro can accept both 230/240 and when inverting produce 230 or 240 depending on how one sets it up.
VERY importantly, I am NOT interested in converting the 240/120 v split phase to a 120v output (I have my other Quattro for that if I plug into 120 v 30 amp shore power).
Also importantly, I will only have 2 consumables for this 230 v 8 kva Quattro. One is an induction cooktop that happily accepts 230 or 240 as well as 50 or 60 Hz. The other is an Air Cond that also happily accepts 230 or 240 v as well as 50 or 60 Hz. So I do NOT need to transform the source voltage. Unless I need an autotransformer for some other reason, I do NOT need an autotransformer to change 240/120 v split phase to some other voltage.
I looked at the User Manual for the Quattro, and unless I missed it I do not see how to wire the Quattro. I know that my setup is less usual than most systems since fewer people have 240 v consumables. This is why most questions address converting the 4 wire US power to 2 legs of separate 120 v power, which I don’t want to do.
Specifically:
a) How do I place the wires from the 4 wire source (2 hots,1 neutral, 1 ground) to the 230/240 v Quattro?
b) Or if this is not preferred or possible, is there another way to do this, e.g. possibly to tie one of the hot wires to the neutral (since I believe it it won’t be needed for straight 240 v power in my case) , and this way BEFORE it gets to the Quattro, I have converted 4 wires to 3 wires (Hot, Hot/Neutral, Ground). I have read it is fine to not use the neutral when 240v power is needed since no need to balance the two 120v legs.
You need to understand that European 230V power has a Neutral that isn’t the same as the Split Phase Neutral used in the US. These are incompatible power systems.
The only way to use the European 8k Quattro is to connect split-phase L1 to Quattro Line (L), and split-phase L2 to Quattro Neutral (N). Do NOT connect the split-phase Neutral to anything, put a wire nut on it! The split-phase Ground should go to PE ground.
You have to set the Quattro to 60 Hz, even if your devices can take 50 Hz, because the Quattro checks the input frequency. 230 or 240V is up to you, but I’d set it to 240V because that is the US standard. Remember that the output of the Quattro is for 240V loads only.
Never ever connect a 120V load to the quattro output by borrowing a split-phase neutral from somewhere.
Most importantly, the Ground Relay MUST be disabled, because activating it would connect the Quattro Neutral (now actually hot L2) to the PE connection. This would put live voltage on the chassis and ground lines, and hopefully trip breakers, don’t let that happen. Out of the box it is enabled, beware.
Thanks Dave. Single phase on the output (which I gather is typical for the 230 V European Quattro) will work fine with my consumables.
-Induction cooktop is sold for international use so can be wired as 2 hots and 1 grd or as single phase with 1 hot, 1 grd, 1 neutral).
-HVAC system is European and can be wired as single phase 1 hot, 1 grd, 1 neutral.
Based on my answers to your question do you have any advice for me? Rick replied, which I appreciate very much, and I am happy for all opinions/perspectives (ideally not conflicting advice which sometimes happens!).
Thanks for your reply Rick! As a follow up question you mentioned needing to disable the Ground Relay. I quickly looked up disabling the Ground Relay and saw this post in this forum below:
Kevin previously wrote in this forum (2021), that “Multi/Quatro programming allows the input relay to be disabled in special situations where the safety-neutral connection is made elsewhere. But generally, the ground relay should not be disabled.”
Can you please clarify what he might have meant by “connection made elsewhere” and if you agree necessary how best to achieve this?
Thanks again!
In a normal European Quattro installation, when the grid is disconnected and the inverter takes over, there is a need to bond the inverter Neutral output to the PE Ground for safety reasons. It is needed for RCD (what we call GFCI) protection and to handle ground faults.
The US split-phase system has a similar requirement, but the neutral is at a different voltage relative to the hot conductors.
In your case, you are doing a very non-standard installation. The purpose of the ground relay in your case is not applicable. As mentioned above, from a legality point of view, you may run into issues.
I definitely make no claims about code compliance or legality, just that electrically, it will function.
If I were doing this, I would connect the output of the 8k quattro to a load center (breaker panel) clearly labeled 240V Only, with no neutral bus bar, only L1, L2, and Ground. All breakers would be required to be two-pole.
Thanks. Would the Victron Autotransformer (32 amp vs 100 amp model?) be appropriate? I already have FS60 Galvanic Isolators and am rarely at a marina. Or, would the Victron Isolation Transformer be more appropriate? I looked at their data sheets but I don’t have expertise to interpret. I don’t think I need the isolation feature (but maybe I am wrong) and it also ways twice as much.
An auto transformer would be able to convert one leg of the split phase to your required 240v single phase. You will of course be limited to ~25a 240v though
Then everything beyond the transformer gets wired like a typical 240 single phase
For power requirements you asked about, I was marginal with a 5 kva unit since my HVAC unit will run at 2-3 kw most of the time (but max of 4 kw) and then I will have rare intermittent use of the induction cooktop (1.8 kw max) since I also have a 120 v cooktop I can rely on through a 120 v Quattro most of the time. So I figured the 8 kva (with kw being less than 8 kva) would be optimal. Are there good large (8 kva) inverter chargers sold in US that are better for my system (that is 240 v split phase 50 amp shore power)? I have Victron ecosystem so hoped to keep it all Victron. I am surprised Victron does not apparently have an easy solution for this.
I guess it’s up to you if you want to go a different route now that you’re already got the single phase inverter.
I would take a step back and reassess what you want to do here.
I would personally abort mission with the current 120v inverter already onboard and this 8kva single phase. I would cut my losses and try to sell those units and set up a proper 120/240 split phase system, not only for simplicity sake but safety. Especially if everything is already set up on split phase circuits, why make things more complicated than they need to be.
Victron doesn’t have the best options for split phase, especially inverting split phase. Their solution is either run a pair of single phase inverters in split phase mode or use a transformer
Generally speaking, the smaller units provide more bang for the buck so if space permits you can save a few bucks doubling up on smaller units rather than 2 big ones.
Hi Boater i have installed systems for more than 20 yachts with the same setup that you are proposing. For use with the usa style 240/120 60hz shore power supply as the input.Feels strange to connect shore power L2 to a terminal labeled neutral but it works.
I don’t doubt it works, unless you plug into somewhere that was home jobbie wired with the breaker double tapped or a jumper between legs (seems pretty common for rv sites lol)
I just don’t know why anyone would want to have the clutter and cost of running 2 separate ac systems, 2 dc systems and 2 battery banks when you could just set it up “right” with a split phase configuration.
yep we get our share of home jobbie wired docks but if system is protected by RCD or similar device the yacht just will not connect .
Alot of boaters like to have redundant systems on their yachts so some complexity in that.
IMO a semi-redundant system in this scenario would be the 4 inverter split phase configuration. Still nice and simple with one dc system and one ac system and as long as you’ve got a programming cable onboard you’re still able to operate it at 1/2 capacity. The chances of losing a third inverter in one trip are pretty slim!
I have a similar setup in a motorhome. If you use the inverter to power only 240 volt equipment, there is no need for an autotransformer on the output side. You would just connect the two hot leads and the ground to the appliances, obviously through the appropriate circuit breakers or panel, etc. 240 volt does not use a neutral. However, if you want to power 120 volt equipment an autotransformer is required, I would recommend a 100 amp unit. This article may help. One thing you may want to consider. I carry an additional 32 amp autotransformer in case I have to connect to 120 volt shore power. As the inverter only inputs 240 volts, the autotransformer converts the 120 volts to 240. The maximum 120 volt shore power is 30 amps (at least for campsites) a 32 amp autotransformer works fine. As mentioned above, for the shore power input you only input the two hot leads and ground. The neutral is not used. Again, I might consider the post to use only one inverter and run everything through one electrical panel.
Thanks Dave. To clarify my boat has only one house bank (24 v, 31 kwh), one main DC system (24v) with small 12v battery for VHF, NAV lights. It is a primarily 120 v boat for us mostly in US. The need for a separate simple AC system (230/240 v power) is for a European HVAC system that I mentioned in my question can run on 230/240 and 50/60 Hz. So I am “stuck” needing single phase 230/240 v power coming out of the 8 kva Quattro for this main consumable. In the US I can plug into 30 amp shore power to supply 6kw to my 120 v Quattro and charge the batteries, then the batteries can power the HVAC via the inverter. BUT in an ideal world, I would be also able to plug in at dock (using a different 50 amp shore power inlet) into 120/240 v 50 amp split phase shore power in the US and have those 12kw of power going to my 8 KVA Quattro to run the HVAC (4 kw), induction cooktop (1.8 kw), and also charge batteries (4.8 kw charger) while at a dock. This is all greater than 6kw from a 30 amp shore power connection (hence desire to be able to plug into 12 kw 50 amp shore power).