Victron Quattro + Autotransformer for split phase (which option is best?)

[Surferdudemi]

For US market yes that would be ideal.

Are you suggesting their 48v 230v 50Hz can work at 240v 60 Hz with the added cost of the auto transformer or some other add on ?

A bit pricey but would that be an option??

I run a bunch of Victron gear with my Schneider CSW 4048 which was more cost effective even after adding the ComBox.

You can't convert 60Hz to 50Hz with a transformer. Or am I misreading the posts? If you have two devices, one taking 50Hz or 60Hz to charge a battery and then another taking DC to produce 60Hz to 50Hz, respectively, you could swing it, but that's a bit convoluted. For high-power applications, I've read that they use motor-generators, but I don't think that applies here. When I lived overseas for a couple of years, I got a large transformer box to convert 240VAC to 120VAC, but things with motors didn't like it - like my blender - because the frequency was low.

 

[Surferdudemi]

You saw 2.5 year payback for a system with lifespan several times that? What utility rate per kWh and what battery cost?

My TOU rates are $0.15, $0.30, $0.45/kWh. Used to be (with other rates), peak was Noon to 6:00 PM so I could be a net producer. Now 4:00 to 9:00 PM, not much PV production available. My area of the country is expensive. Elsewhere, electricity rates are a fraction of that.

With $0.30 spread and battery costing $0.20/kWh, battery system costing $0.30, can't win.
Even if no net metering, better to curtail PV production for no export than to store power.

Some people have to pay "demand charge" based on peak draw. If infrequent, battery could help there. But I think better to just shut off loads to reduce peak draw (maybe fill in valley during different hour). Or over-panel more.

Some commercial rates may reach $0.60 or $1.00, so more cost effective.

Standby generators are another option. I looked at a small one, decided the labor for oil changes was worth more than the power produced. Trukinbear posted his costs to run a diesel generator. Cost per kWh was higher than my top-tier rates. So worthwhile for some purposes, but not to offset grid consumption.

I think many people will invest in battery systems thinking it will save them money, but it will cost them more in the long run.

The primary purpose of my batteries is to power the island grid so grid-tie PV inverters have somebody to play with. During blackouts, I can run A/C an everything else direct off PV. At night, battery can barely keep my several refrigerators and other loads running until dawn. I should set up load-shed of those at night when grid is down. Could have 1/4 the battery in that case. But my 20 kWh battery is reasonable to support the entire house during brief times (minutes) when GT inverters drop off line, and to suck down their output for a few seconds during load-dump, while frequency-shift occurs.

In my case none of that is cost-effective, just as luxury and convenience.
A small system could run phone and internet/laptops.
A generator run a few hours per day would chill the refrigerators and freezers.

After reading a couple of threads here (I'm new to the forums), I did some pricing on batteries. If my math is correct, LiFePO4 batteries get down to about $0.06 / kWH for their lifetime (I used 3500 cycles). That does not include the other equipment that would be necessary to make load-shifting work. I was looking at rates here over the past month, because they just killed the premium for net-metering. Was considering going to a 3-tier rate at $0.158 / $0.232 / $0.114, but I would have to drop net-metering altogether and turns out they charge you for OUTGOING kWH because of the way they reprogram the meter. There is a two-tier rate of $0.227 / $0.120 that is compatible with net-metering that seems to offer a better opportunity, and the high-cost hours fit right in with the PV array generation time (11am - 7 pm). What I was looking for here was if anyone has implemented load-shifting and written about it. I've studied the Sunny Island a bit, and found that it doesn't support LiFePO4. Was hoping that problem had been resolved as these seem like well-designed devices that might be able to make it work, but so far have not found anything on the forums. (Currently have a 1.4kW array and a Xantrex 3.0 kWH inverter. I realize this doesn't play nicely with the SI6048.) One missing feature is day-of-week, since weekends are always off-peak on the 2-tier rate, so it wouldn't make sense to waste battery life on those 2 days of the week.
Has anyone put such a system together? What are the best choices for the inverter/charger/local grid device(s)?

 

[JoeHam]

You can't convert 60Hz to 50Hz with a transformer. Or am I misreading the posts? If you have two devices, one taking 50Hz or 60Hz to charge a battery and then another taking DC to produce 60Hz to 50Hz, respectively, you could swing it, but that's a bit convoluted. For high-power applications, I've read that they use motor-generators, but I don't think that applies here. When I lived overseas for a couple of years, I got a large transformer box to convert 240VAC to 120VAC, but things with motors didn't like it - like my blender - because the frequency was low.

I believe the Victron can switch from 50 to 60hz.

Then the transformer takes care of the voltage.

 

[Surferdudemi]

I believe the Victron can switch from 50 to 60hz.

Then the transformer takes care of the voltage.

I don't see anything in the manual here: https://www.victronenergy.com/uploa...ttro-3k-50-50A-120V-(firmware-xxxx4xx)-EN.pdf
to support this. The inverter itself will allow a wide voltage input range of 45-65Hz. But it will not convert it. In fact, in the 240V unit's manual it says "Once synchronised, the output frequency will be equal to the input frequency." Changing frequency would require converting to DC and then synthesizing back to AC at a different frequency. The efficiency would take a big hit. If you need this feature, you might accept that, but people shopping for best efficiency (e.g., CEC) would avoid that inverter. You would also have to dissipate additional heat.

 

[cinergi]

I don't see anything in the manual here: https://www.victronenergy.com/uploa...ttro-3k-50-50A-120V-(firmware-xxxx4xx)-EN.pdf
to support this. The inverter itself will allow a wide voltage input range of 45-65Hz. But it will not convert it. In fact, in the 240V unit's manual it says "Once synchronised, the output frequency will be equal to the input frequency." Changing frequency would require converting to DC and then synthesizing back to AC at a different frequency. The efficiency would take a big hit. If you need this feature, you might accept that, but people shopping for best efficiency (e.g., CEC) would avoid that inverter. You would also have to dissipate additional heat.

Yes you can switch the output frequency in the configuration.

 

[Surferdudemi]

Yes you can switch the output frequency in the configuration.

That is the system frequency, not just the output frequency. Show where it allows you to set a 50Hz input frequency and a 60Hz output frequency.

 

[snoobler]

That is the system frequency, not just the output frequency. Show where it allows you to set a 50Hz input frequency and a 60Hz output frequency.

There isn't. Input and output frequencies must be the same.

 

[JoeHam]

So for US based power you would use 60Hz in/out system and a transformer to achieve 240v or 120v to make it work for us in US.

 

[Hedges]

So for US based power you would use 60Hz in/out system and a transformer to achieve 240v or 120v to make it work for us in US.

During grid failure, does the quattro disconnect both poles or only one?
If both, fine. If only one, can't use an auto transformer, must use an isolation transformer.

If only one ... If you have a unit intended for European 220V L to N, and you connect it across U.S. 120/240V L1 to L2, when grid fails L1 is disconnected from L on Quattro's output, but L2 remains connected to N. If you connect a 120/240V auto-transformer with center tap grounded, the inverter will make 220V (or 240V if so adjusted) across the transformer. Center tap is held at ground, so L is 120V and N is 120V (but 180 degrees out of phase). L is disconnected from L1, but N is connected to utility L2 and backfeeds power into the grid while grid is down.

"The Quattro is provided with a ground relay (see appendix) that automatically connects the N output to the casing if no external AC supply is available. If an external AC supply is provided, the ground relay will open before the input safety relay closes (relay H in appendix B). This ensures the correct operation of an earth leakage circuit breaker that is connected to the output. In a fixed installation, an uninterruptable grounding can be secured by means of the grounding wire of the AC input. Otherwise the casing must be grounded. In a mobile installation (for example, with a shore current plug), interrupting the shore connection will simultaneously disconnect the grounding connection. In that case, the casing must be connected to the chassis (of the vehicle) or to the hull or grounding plate (of the boat). In general, the connection described above to shore connection grounding is not recommended for boats because of galvanic corrosion. The solution to this is using an isolating transformer."

"Procedure Use three-core cable. The connection terminals are clearly encoded: PE: earth N: neutral conductor L: phase/live conductor"

Best to bypass that Neutral to ground bond if you're going to connect one leg of 120/240V grid to neutral. Don't want a relay completing circuit to ground when 120V from grid is applied to it.

 

[cinergi]

That is the system frequency, not just the output frequency. Show where it allows you to set a 50Hz input frequency and a 60Hz output frequency.

Nobody is saying it can convert. Only that it can operate at either 50 or 60 hertz.

 

[cinergi]

During grid failure, does the quattro disconnect both poles or only one?
If both, fine. If only one, can't use an auto transformer, must use an isolation transformer.

If only one ... If you have a unit intended for European 220V L to N, and you connect it across U.S. 120/240V L1 to L2, when grid fails L1 is disconnected from L on Quattro's output, but L2 remains connected to N. If you connect a 120/240V auto-transformer with center tap grounded, the inverter will make 220V (or 240V if so adjusted) across the transformer. Center tap is held at ground, so L is 120V and N is 120V (but 180 degrees out of phase). L is disconnected from L1, but N is connected to utility L2 and backfeeds power into the grid while grid is down.

"The Quattro is provided with a ground relay (see appendix) that automatically connects the N output to the casing if no external AC supply is available. If an external AC supply is provided, the ground relay will open before the input safety relay closes (relay H in appendix B). This ensures the correct operation of an earth leakage circuit breaker that is connected to the output. In a fixed installation, an uninterruptable grounding can be secured by means of the grounding wire of the AC input. Otherwise the casing must be grounded. In a mobile installation (for example, with a shore current plug), interrupting the shore connection will simultaneously disconnect the grounding connection. In that case, the casing must be connected to the chassis (of the vehicle) or to the hull or grounding plate (of the boat). In general, the connection described above to shore connection grounding is not recommended for boats because of galvanic corrosion. The solution to this is using an isolating transformer."

"Procedure Use three-core cable. The connection terminals are clearly encoded: PE: earth N: neutral conductor L: phase/live conductor"

Best to bypass that Neutral to ground bond if you're going to connect one leg of 120/240V grid to neutral. Don't want a relay completing circuit to ground when 120V from grid is applied to it.

A European 230v 50hz unit operating in the US must be configured to 240 60 hz and then connected to an autotransformer with the quattro ground relay turned off and configured to enable the ground relay on the autotransformer.

 

[Hedges]

A European 230v 50hz unit operating in the US must be configured to 240 60 hz and then connected to an autotransformer with the quattro ground relay turned off and configured to enable the ground relay on the autotransformer.

I am going to disagree, unless you can say the European unit has a 2-pole disconnect.

It it only disconnects one pole, I think it must be used with an isolation transformer, not an auto transformer. Using an autotransformer with center tap grounded, it would force 120V back into the grid through the AC input terminal which was intended to be European Neutral.

Perhaps the Victron does have a 2-pole disconnect. A cheap brand someone else set up did not, based one people tracing the wires inside and examining hardware.

 

[cinergi]

I am going to disagree, unless you can say the European unit has a 2-pole disconnect.

It it only disconnects one pole, I think it must be used with an isolation transformer, not an auto transformer. Using an autotransformer with center tap grounded, it would force 120V back into the grid through the AC input terminal which was intended to be European Neutral.

Perhaps the Victron does have a 2-pole disconnect. A cheap brand someone else set up did not, based one people tracing the wires inside and examining hardware.

I don't have one to test with but Victron supports the configuration:

https://www.victronenergy.com/upload/documents/AT-1-split-phase-240V-to-120-240V-with-Quattro-240V.pdf

 

[Hedges]

I don't have one to test with but Victron supports the configuration:

https://www.victronenergy.com/upload/documents/AT-1-split-phase-240V-to-120-240V-with-Quattro-240V.pdf

It's got it: isolation of both "L" and "N", on both "Generator" and "Shore Power" inputs.
So works fine with auto-transformer.
(Just don't try this with off-brand inverters unless you confirm the same.)

 

[Surferdudemi]

Nobody is saying it can convert. Only that it can operate at either 50 or 60 hertz.

Well, that's why I originally asked if I was misreading the question, LoL.