High frequency verses low frequency inverters

[42OhmsPA]

I wish I could find this inverter in stock ANYWHERE.
It’s the only one they list with 240a of charge controller. The 12k only does 120a (7000w) that 18k would be awesome for a 100a main service

Looks very similar...

18000W 48V Split Phase Pure Sine Wave Inverter Charger

Sungoldpower 18000W 48V Split Phase Pure Sine Wave Inverter Charger. Pure Sine Wave Inverter charger 48v is a combination of an off grid inverter, AC charger, and Auto-transfer switch into one complete system. The whole house inverter is packed with unique features and it is one of the most...

sungoldpower.com

 

[G00SE]

Looks very similar...

18000W 48V Split Phase Pure Sine Wave Inverter Charger

Sungoldpower 18000W 48V Split Phase Pure Sine Wave Inverter Charger. Pure Sine Wave Inverter charger 48v is a combination of an off grid inverter, AC charger, and Auto-transfer switch into one complete system. The whole house inverter is packed with unique features and it is one of the most...

sungoldpower.com

Indeed. Just lacks the MPPT

 

[42OhmsPA]

Indeed. Just lacks the MPPT

I thought so too when I first looked at it....
I suspect it's the same inverter with crappy spec copying / creation on SGP part.

 

[Crowz]

Does anyone make a LF high capacity AIO? Suspect not, as that expense segment tends to be willing to assemble individual components.

18000W 48V Split Phase Pure Sine Wave Inverter Charger

Sungoldpower 18000W 48V Split Phase Pure Sine Wave Inverter Charger. Pure Sine Wave Inverter charger 48v is a combination of an off grid inverter, AC charger, and Auto-transfer switch into one complete system. The whole house inverter is packed with unique features and it is one of the most...

sungoldpower.com

Main Specification：
Continuous Output Power :18.0KW
Surge Rating(20s) :54.0KW
Output Waveform ure Sine Wave

But it doesn't have pv inputs.

But if you really needed that much juice I would think a separate charger would be worth it

 

[Delmar]

I have both a 48V 2700W low-frequency UPSverter and Reliable 2500W high-frequency inverter. My golf cart FLA supplies the battery power. Both are only for grid-down backup that is tied into my breaker panel.

The 5U case 2700W APC UPSverter weighs in around 90 lbs. Without batteries. I had to get a roller dolly to move the beast around.

The UPSverter will start my ½HP garbage disposal or garage door opener without blinking. The inverter will struggle and brownout the entire house while attempting to start.

Performed a fridge power test that draws only 110 watts AC:
* 2700W APC UPSverter beast draws around 4.5A @ 50V = 225W. Not efficient at all with low load.
* 2500W Reliable draws around 2.5A @ 50V = 125W. When the fridge was disconnected the no-load amps was 0.4A = 20W.

Not that it’s a concern for me, but the Reliable was dead silent with the low loading not requiring the fans. Conversely the UPSverter would start both megafans regardless of temperature or loading, and the dual huge transformers emit a 60hz hum. If you are placing an inverter inside your living space this could be an issue.

 

[G00SE]

Looks very similar...

18000W 48V Split Phase Pure Sine Wave Inverter Charger

Sungoldpower 18000W 48V Split Phase Pure Sine Wave Inverter Charger. Pure Sine Wave Inverter charger 48v is a combination of an off grid inverter, AC charger, and Auto-transfer switch into one complete system. The whole house inverter is packed with unique features and it is one of the most...

sungoldpower.com

Indeed. Just lacks the MPP

I thought so too when I first looked at it....
I suspect it's the same inverter with crappy spec copying / creation on SGP part.
View attachment 161687

@Crowz as well since I couldn’t figure out how to quote you both!
You all are awesome. Love that there’s consistent feedback of potential alternatives.
I think I’ve resigned myself to going with the 12k GW. I’ll make do with the 7000w panel capacity in the interim and run the rest on a separate controller in the future.
The 18k sounds nice but I think the surge ability of the 12k will be sufficient and not as bad on the idle/waste (still not stellar)

Edit: now my latest debate is the sigineer or the GW version. Seems sigineer May be the original oem supplier so that may be a better avenue.
I can get a GW12k local with a spare board for the cost of the sigineer shipped (no spare board)

 

[42OhmsPA]

I thought so too when I first looked at it....
I suspect it's the same inverter with crappy spec copying / creation on SGP part.
View attachment 161687

I lied. Unless you get an old unit. No mppt. I wouldn't want it anyway due to the 100voc limit...

 

[TimE]

Appreciate your perspective (especially since you’ve used both).

Other than pushing power output close to rated limits, can you comment on what other types of ‘abuse’ your LF inverters handled better than your HF inverters?

LF 8nverters can deal with inductive loads reliably. HF inverter can do it until they pop

 

[fafrd]

I have both a 48V 2700W low-frequency UPSverter and Reliable 2500W high-frequency inverter. My golf cart FLA supplies the battery power. Both are only for grid-down backup that is tied into my breaker panel.

The 5U case 2700W APC UPSverter weighs in around 90 lbs. Without batteries. I had to get a roller dolly to move the beast around.

The UPSverter will start my ½HP garbage disposal or garage door opener without blinking. The inverter will struggle and brownout the entire house while attempting to start.

Interesting comparison - thanks.

But just to be clear, the LF UPSverter has no issues starting your 1/2 HP disposal while the HF Reliable inverter cannot do so without browning out the entire house, right?

Can the 2.5kW HF inverter successfully start and run the disposal if that is the only load?

1/2 HP is only 372W continuous, so that should be well within the capability of the HF inverter.

Locked rotor power at startup can be many times that, perhaps 6 or even 8X in the extreme, but that should be 2.32kW to at most 3.0kW and the 2.5kW Reliable inverter claims to have peak surge power of 200% or 5kW, so if it has difficulty starting your disposal, I’m guessing it may be because other loads are consuming over a kW of power?

Performed a fridge power test that draws only 110 watts AC:
* 2700W APC UPSverter beast draws around 4.5A @ 50V = 225W. Not efficient at all with low load.
* 2500W Reliable draws around 2.5A @ 50V = 125W. When the fridge was disconnected the no-load amps was 0.4A = 20W.

Not that it’s a concern for me, but the Reliable was dead silent with the low loading not requiring the fans. Conversely the UPSverter would start both megafans regardless of temperature or loading, and the dual huge transformers emit a 60hz hum. If you are placing an inverter inside your living space this could be an issue.

 

[fafrd]

LF 8nverters can deal with inductive loads reliably. HF inverter can do it until they pop

Meaning a LF inverter handles overload better than an HF inverter and overload can easily damage an HF inverter?

Would you have any concerns about causing an HF inverter to ‘pop’ if it was was never driven past 50% of rated power?

 

[Crowz]

Meaning a LF inverter handles overload better than an HF inverter and overload can easily damage an HF inverter?

Would you have any concerns about causing an HF inverter to ‘pop’ if it was was never driven past 50% of rated power?

Well that depends. The main problem has to do with how do you know it will never be driven past 50% of its rated power?

By the wattage listed on the device? Not so fast. Those numbers rarely if EVER list surge amounts. They are supposed to but in real life settings from my experience... nope.

So IF you get lucky and never drive it past 50% of its load then the HF should do fine. But you can see this going south fast just playing with small 500watt and 1000 watt inverters and watching them shutdown when you plug in something that shows it shouldn't be using but 1/2 of what the inverter can handle. Surge or start up loads if you will is an ugly hidden problem and has been the death of many a nice HF inverter.

 

[rhino]

This is also good example:

 

[Crowz]

I thought sol-ark was supposed to be super nice and all? Did he fib on any of that video?

 

[Hedges]

Continuous Output Power :18.0KW
Surge Rating(20s) :54.0KW

Sounds great for motors.
54kW / 5 = 11kW rated motor that it should be able to start. Something like a 15 HP induction motor!

At 23kW my (4x) SI beats 18kW, but 44kW 3 second surge falls short of 54kW 20 second.

 

[Delmar]

Can the 2.5kW HF inverter successfully start and run the disposal if that is the only load?

1/2 HP is only 372W continuous, so that should be well within the capability of the HF inverter.

I have not attempted to shutdown all other loads and start only the disposal. The other loads would be minimal, only a TV and a few LED bulbs. Doubt over 200W total.

 

[fafrd]

I thought sol-ark was supposed to be super nice and all? Did he fib on any of that video?

No, those are extreme loads. If building a true off-grid system where all home loads are being powered by a single inverter with no access to grid power, LF is almost certainly the better choice than HF.

If only powering a modest CL panel with known loads of modest consumption, different use-case entirely.

On my case, I’m only trying to take my fridges/freezers off-grid. As long as I have an HF inverter with sufficient surge capacity to start each fridge/freezer while all others are running, I should be fine.

The compressor had an 11X locked rotor current, which is the highest I’ve ever heard of.

Average load for all 5 of my fridges and freezers is 400W and the largest one has locked rotor power of less than 11 x 200W = 2200W.

So a 2600W HF inverter should probably handle my CLs just fine.

I’ve got a 3000W WZRELB inverter currently and am toying with the idea of getting a 5+5kW split-phase model.

But part of the rationale of getting a higher-powered split phase inverter was to have the freedom to move other frequent loads such as the toaster oven and coffee maker off-grid, and that was a good video for bringing the importance of power-budgeting home.

5kW per leg gets chewed up awfully quickly at 1800W per bite…

 

[fafrd]

Well that depends. The main problem has to do with how do you know it will never be driven past 50% of its rated power?

In my use case there are only 5 loads and I’ve measured them all (sustained, peak, and startup surge)…

By the wattage listed on the device? Not so fast. Those numbers rarely if EVER list surge amounts. They are supposed to but in real life settings from my experience... nope.

So IF you get lucky and never drive it past 50% of its load then the HF should do fine.

That is comforting to hear.

But you can see this going south fast just playing with small 500watt and 1000 watt inverters and watching them shutdown when you plug in something that shows it shouldn't be using but 1/2 of what the inverter can handle. Surge or start up loads if you will is an ugly hidden problem and has been the death of many a nice HF inverter.

Appreciate the caution. And in my case, I’ll take it to mean that I should be exceedingly cautious before adding additional loads to my off-grid CL panel (do cautious, conservative, and accurate worst-case power budgeting).

Putting 120VAC sockets into the CL panel is obviously something to stay away from if powering from an HF inverter…

 

[fafrd]

I have not attempted to shutdown all other loads and start only the disposal. The other loads would be minimal, only a TV and a few LED bulbs. Doubt over 200W total.

My 65” TV consumes 350W…

But I get your point - under 500W of other loads means 2000W available to startup the 1/2HP disposal.

If we take the 11X locked rotor current of the compressor from that video (highest I’ve ever heard of), that 1/2HP = 372W of running current would translate to 4092W of startup surge.

So the 200% surge rating your 2500W HF inverter claims to deliver is either overstated or cannot be sustained for the amount of time needed to get your disposal running.

Reliable does state that inverter size for running inductive loads should be at least 10X sustained consumption, so 3720W in the case of your 1/2HP disposal…

So maybe you need to upgrade your 2500W HF inverter for a 4000W model .

Sizing HF inverters at 10X maximum inductive load + average load does not sound like a bad rule of thumb…

 

[k490]

No, those are extreme loads. If building a true off-grid system where all home loads are being powered by a single inverter with no access to grid power, LF is almost certainly the better choice than HF.

If only powering a modest CL panel with known loads of modest consumption, different use-case entirely.

On my case, I’m only trying to take my fridges/freezers off-grid. As long as I have an HF inverter with sufficient surge capacity to start each fridge/freezer while all others are running, I should be fine.

The compressor had an 11X locked rotor current, which is the highest I’ve ever heard of.

Average load for all 5 of my fridges and freezers is 400W and the largest one has locked rotor power of less than 11 x 200W = 2200W.

So a 2600W HF inverter should probably handle my CLs just fine.

I’ve got a 3000W WZRELB inverter currently and am toying with the idea of getting a 5+5kW split-phase model.

But part of the rationale of getting a higher-powered split phase inverter was to have the freedom to move other frequent loads such as the toaster oven and coffee maker off-grid, and that was a good video for bringing the importance of power-budgeting home.

5kW per leg gets chewed up awfully quickly at 1800W per bite…

I want to try and offload my 4-ton heat pump. When that thing starts up makes my panel buzz pulling so much current. I will install a soft start to fix that. It does pull 20 solid amps on each leg after startup. I was looking at this split phase bundle two EG4 off grid inverters 13k watts of power. With a soft start installed should be enough to run my AC 2400 watts of power per leg.

 

[WolfMoonWitch]

Just my opinion through my personal experience . Low frequency Inverters are built to last a lifetime ( If there are no user errors ) and high frequency are not
Which is why LF s come with up to 10 year warranty And HF s are generally 5 years or less if at all . So with that being said, LF if you want one for a lifetime you get what you pay for and you do pay as they are more expensive. HF if your on a budget and starting out and plan to buy a better inverter at a later date as they are less expensive and don’t have the longevity.
Only bad thing is this — when is the HF gonna go out? Will it put you in a major or minor bind ?
Just food for thought!

 

[Crowz]

Just my opinion through my personal experience . Low frequency Inverters are built to last a lifetime ( If there are no user errors ) and high frequency are not
Which is why LF s come with up to 10 year warranty And HF s are generally 5 years or less if at all . So with that being said, LF if you want one for a lifetime you get what you pay for and you do pay as they are more expensive. HF if your on a budget and starting out and plan to buy a better inverter at a later date as they are less expensive and don’t have the longevity.
Only bad thing is this — when is the HF gonna go out? Will it put you in a major or minor bind ?
Just food for thought!

That's why I have both and if I had to choose it would be the LF.

I put my tp6048 LF inverter in the house my mother lives in powering her oxygen generator and the ac and the power to the rooms she's in.

The new HF inverter is on my main house. I can switch to the generator if I had to on the main house.

I think you will see where the important one is and which inverter is running it

I'm using HF on my crypto stuff since they are cheap, lighter in weight and can be looked at as disposable as more powerful units come on market. More power = more $$ made at less cost of ownership.

 

[Mattb4]

Just my opinion through my personal experience . Low frequency Inverters are built to last a lifetime ...

Some are and some aren't. I can point you to Power Jack as an example of LF inverters that likely will not last a lifetime unless you are expecting to get hit by a bus this afternoon.

 

[ksmithaz1]

I want to try and offload my 4-ton heat pump. When that thing starts up makes my panel buzz pulling so much current. I will install a soft start to fix that. It does pull 20 solid amps on each leg after startup. I was looking at this split phase bundle two EG4 off grid inverters 13k watts of power. With a soft start installed should be enough to run my AC 2400 watts of power per leg.

My Goodman 4T unit is on the roof. The highest sustained usage, like now, is 5KW. My EG4 18KPV's grumpily started it before I got the Micro Air, UPS's would kick in on the computer gear, lights would dim, etc. Now it will blink LED bulbs sometimes, The CF's, and UPS's don't notice. I don't think a low-frequency inverter is worth it unless you are running a lot of heavy equipment. Heavy, and more expensive.

 

[WolfMoonWitch]

Some are and some aren't. I can point you to Power Jack as an example of LF inverters that likely will not last a lifetime unless you are expecting to get hit by a bus this afternoon.

Agreed ! Some are some aren’t some do some don’t ! Just as some HF have a 10 year warranty such as eg4 18kpv for example however more times then not the LF will last longer especially with heavy loads. But as you stated not all inverters are created equal ( LF or HF )
Just my choice for longevity purposes I will go LF!
Which brings up an interesting question I may post for those whom know more then I as there are many….. is there a way to use and utilize both LF & HF together on same system simultaneously, to get the best of both words with each having auto shutdown? Hmmmm that would be a system gene pool
One active for efficiency, other for big load, perhaps a capacitor bank that works with battery bank may be more doable
Dang this rabbit hole goes deep

 

[Ellcon123]

You are assuming one is more efficient than the other which isn't the case. Depends on what you buy or make.