46kW generator too big for two Deye 12K/Sunsynk 12K/Sol-Ark 15K?

[shadowmaker]

I have 2x Deye 12K and about 100kWh of batteries. Up here in Finland my batteries are most of the time empty at this time of year so no backup for blackouts (which are thankfully quite rare). Generator sweet spot should be around 75-80%, so this one should be used close to 35kW, but I can only charge my batts around 21-22kW. It would be quite easy for me to add ~15kW more loads when using a generator (3x water heaters, pool heater, geothermal heating, 3x heat pumps...), but is there a bypass when using gen port? I mean can a generator be used only for charging my batts, or can it also be used to cover my loads at the same time? If so, how big is the bypass?

 

[Steve_S]

Your generator is certainly big enough no worries there. The Chargers will only pull what they need to charge the batteries per the settings as you know you can set the charging amps. Typically (I do not have exp with Deye) Passthrough is above and beyond the charging pull. So if the house needs 25A to continue operating and your pulling 100A for charging, the total pull would be 125A + a bit for losses, so maybe 127A.

I use Samlex, I have it set to charge at 80A (can do 100) and it handles the Passthrough to the house automatically. I can observe the incoming power and see when loads happen and the spike is handled transparently without affecting the charge rate, unless it's a really big load, which is prioritized and charge amps drop as a result.

Word of CAUTION !
There are NO Inverter/Charger Systems that can change the Sine Wave ! Whatever Sine Wave the Genset uses is passed through "as is" ! Inverters output Pure Sine and most generators (non inverter) are MOD SINE and that can be messy power. They will also float in frequency, so in your case you could see the frequency shift around from 45 to 55hz and I guarantee some things will NOT like that... Watch your digital clocks & devices.

Another Angle if your genset has two AC outputs with sufficient amperage per, you could wire one to service & ATS to House Circuit and the other to the Inverter/Charger AC input Circuit.

 

[Supervstech]

Your generator is certainly big enough no worries there. The Chargers will only pull what they need to charge the batteries per the settings as you know you can set the charging amps. Typically (I do not have exp with Deye) Passthrough is above and beyond the charging pull. So if the house needs 25A to continue operating and your pulling 100A for charging, the total pull would be 125A + a bit for losses, so maybe 127A.

I use Samlex, I have it set to charge at 80A (can do 100) and it handles the Passthrough to the house automatically. I can observe the incoming power and see when loads happen and the spike is handled transparently without affecting the charge rate, unless it's a really big load, which is prioritized and charge amps drop as a result.

Word of CAUTION !
There are NO Inverter/Charger Systems that can change the Sine Wave ! Whatever Sine Wave the Genset uses is passed through "as is" ! Inverters output Pure Sine and most generators (non inverter) are MOD SINE and that can be messy power. They will also float in frequency, so in your case you could see the frequency shift around from 45 to 55hz and I guarantee some things will NOT like that... Watch your digital clocks & devices.

Another Angle if your genset has two AC outputs with sufficient amperage per, you could wire one to service & ATS to House Circuit and the other to the Inverter/Charger AC input Circuit.

Wait...
How can a generator output anything but a pure sine wave?

Sure, the frequency can shift all over the place due to rpm... but the wave is a wave from the gen head design... no?

 

[houseofancients]

I have 2x Deye 12K and about 100kWh of batteries. Up here in Finland my batteries are most of the time empty at this time of year so no backup for blackouts (which are thankfully quite rare). Generator sweet spot should be around 75-80%, so this one should be used close to 35kW, but I can only charge my batts around 21-22kW. It would be quite easy for me to add ~15kW more loads when using a generator (3x water heaters, pool heater, geothermal heating, 3x heat pumps...), but is there a bypass when using gen port? I mean can a generator be used only for charging my batts, or can it also be used to cover my loads at the same time? If so, how big is the bypass?

These inverters can use any input from the genport almost the same way as solar, with the exception of delivering back to the grid when using a gen ( would be completely senseless to do too btw).

So yes, it can power your loads and charge your battery at the same time..
However, you will be limited by the max amps of the gen/aux port, and you cannot "split" your 46kwh gen output over more inverters..

If you need ( or want) to use the full 46kwh..
I'd put the Genny in the grid panel ( and using a manual transfer switch to switch between grid and Genny)..
That way you can use all your deye's , and make full use of your Genny and have it run at it's most efficient out put

 

[Millennium]

I have 2x Deye 12K and about 100kWh of batteries. Up here in Finland my batteries are most of the time empty at this time of year so no backup for blackouts (which are thankfully quite rare). Generator sweet spot should be around 75-80%, so this one should be used close to 35kW, but I can only charge my batts around 21-22kW. It would be quite easy for me to add ~15kW more loads when using a generator (3x water heaters, pool heater, geothermal heating, 3x heat pumps...), but is there a bypass when using gen port? I mean can a generator be used only for charging my batts, or can it also be used to cover my loads at the same time? If so, how big is the bypass?

Sol-Ark told me that their 15K cannot accept a 35kW generator in the gen port.
I would need to add it on the grid side and use a transfer switch between the grid and generator.

 

[houseofancients]

Sol-Ark told me that their 15K cannot accept a 35kW generator in the gen port.
I would need to add it on the grid side and use a transfer switch between the grid and generator.

Well that is what I wrote.

Deye 12k 3 phase = Sunsynk 12k 3 phase / ~ sol-arks 15k

 

[Steve_S]

This is a basic explanation that is fairly good.

What Is Sine Wave Output [Quick Overview]

What is sine wave output, and do you need to consider when selecting an inverter generator? This quick overview will explain why it's important.

pluggedinacademy.com

BTW: I was also an ECNE, EMCSE, CBE (Banyan Vines) and more as an IT Core Engineer for DND. The creds expired & left.
Of course as a retired Core IT Engineer what the hell do I know...

 

[RCinFLA]

Large generator power is fine, but you cannot load inverter's pass-through current beyond the pass-through relay limit. Pass-through relay carries AC output loads plus any AC charging used for charging batteries. Deye 12k maximum continuous pass-through load current is 45 amps AC.

Generators are sinewave output although some constant speed synchronous generators have some distortion of sinewave output. Distortion usually does not cause problems although it creates some current loading variance on inverter. When pass-through relay closes the inverter is running in parallel with generator so if generator waveform does not match inverter waveform it causes some current sharing variations across the AC cycle.

If distortion is extremely bad the inverter will release from generator due to inverter peak current limit being exceeded.

The most critical generator parameter for a synchronous generators is governor rpm speed control stability. If synchronous generator engine rpm speed varies it creates frequency/phase wobble that the inverter will not be able to stay in sync with, causing inverter to release from generator. Specification-wise, if frequency of generator wobbles at a rate more than about 0.3 Hz per second the inverter will release from generator.

 

[Bkord]

Wait...
How can a generator output anything but a pure sine wave?

Sure, the frequency can shift all over the place due to rpm... but the wave is a wave from the gen head design... no?

I agree. It’s a chunk of spinning copper.

 

[RCinFLA]

This is a basic explanation that is fairly good.

What Is Sine Wave Output [Quick Overview]

What is sine wave output, and do you need to consider when selecting an inverter generator? This quick overview will explain why it's important.

pluggedinacademy.com

Inverter-generators are three-phase alternators rectified to high voltage DC which powers a DC to AC inverter.

About 15-20 years ago I did see a cheap Chinese inverter-generator that had a modified sinewave inverter, but I have not seen any inverter-generators not using sinewave inverters for many years.

The alternator output voltage varies with load current, so you need the PWM sinewave inverter to regulate the AC output voltage. A simple modified sinewave inverter would need a high voltage DC regulator which would add more cost than just including a PWM sinewave inverter.

 

[Supervstech]

This is a basic explanation that is fairly good.

What Is Sine Wave Output [Quick Overview]

What is sine wave output, and do you need to consider when selecting an inverter generator? This quick overview will explain why it's important.

pluggedinacademy.com

BTW: I was also an ECNE, EMCSE, CBE (Banyan Vines) and more as an IT Core Engineer for DND. The creds expired & left.
Of course as a retired Core IT Engineer what the hell do I know...

That is discussing INVERTER generators…

 

[shadowmaker]

So much information for an idiot like me...

The gen I'm planning to get is an old diesel one from late 60's. It looks like new, very robust and has low operating hours. The thing is that I can protect my LED TVs, computers and such with the two UPS (3kW and 7,7kW) I already have, but can the electronics of my 15kW air compressor or 37kW(output) geothermal cope with this type of old generator? Would the output be "clean" enough? Back when this genny was made they didn't have to worry about electronics being killed with it.

 

[Bkord]

So much information for an idiot like me...

The gen I'm planning to get is an old diesel one from late 60's. It looks like new, very robust and has low operating hours. The thing is that I can protect my LED TVs, computers and such with the two UPS (3kW and 7,7kW) I already have, but can the electronics of my 15kW air compressor or 37kW(output) geothermal cope with this type of old generator? Would the output be "clean" enough? Back when this genny was made they didn't have to worry about electronics being killed with it.

If the gen is sized right and functions correctly it should be fine. I would take an old diesel over any gas one.