High frequency verses low frequency inverters

[WolfMoonWitch]

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

You are correct. The Efficiency I was referring only to wattage used in idle time.
As LF generally use more the HF
I should have been clearer but felt I was rambling and didn’t want to go overboard

 

[Ellcon123]

Would agree that most HF's have good idle, even cheap ones. A good LF with toroidal transformer though is 20~30W idle so no worse than a HF. Mines about 22W. Again, depends on what you buy.

 

[Hedges]

10 year warranty is simply the price to enter the California grid-tie market.

Other than that, I remember longer warranties on cars as a way to entice or give confidence to buyers who knew some foreign brands were more reliable.

 

[Kingrex]

I have been spinning around this for a while. Digging into spec and watching video. I am powering Audio Video equipment. I need a very clean sine wave. It has to handle very quick transient peak. You know, subwoofers demanding current. The sine wave can in no way clip the tops as I have heard of $100,000 amplifiers fry their circuits from clipped sine waves.

So hear is the issue. Even though companies advertise low frequency inverters as pure sine wave, the wave is disgusting. Especially under load. All but Victron advertise 10% harmonic distortion. When video show tbem loaded, the sine wave are incredibly chopped, spiked. They look more like 30% to 40% distorted. Even the Victron inverters look pretty bad.

I was ignoring high frequency inverters as their sine waves seem to completely collapse under load. But I'm wondering about an Exeltech XP2000. They claim their sine wave wont distort more than 2% if you load it under 2000 watts.
Does anyone know if any video ha e been posted of a XP2000 where a fluke scopemeter is attached to the Exeltech and the wave monitored under various loads.

 

[Kingrex]

Also, what are the cleanest low frequency inverters. Sungold says they are going to fall apart under load. 10% to 15% distortion. Thats horrible. That is with their brick inverters in the 3000w to 4000w. They advertise tbeir 12,000 watt wall mount as 3%. Unfortunately their support group has decided I ask to many questions and are not providing and additional detail on the performance of their equipment.

Iooked ag Spartan which is a rebranded Aims. The charger is to simplistic and of poor design to work. I don't even think I could bypass it to use a stand alone charger.

 

[Hedges]

Your stereo doesn't run on 60 Hz AC, it runs on DC.
If it has a linear power supply, those can be even noisier than switch-mode supplies, because they work by rectifying sine wave into a capacitor, drawing current that is clipped off top of sine wave.

We deal with the 120 Hz harmonics of that at work.

What is the DC bus voltage of your power amplifier?
You talk about inverters, so powered from batteries and maybe PV.
How about setting up LiFePO4 battery of desired voltage and charging it with MPPT charge controller.
Feed directly into DC rail of amplifier.
Extra custom filter if it is necessary to block the switching frequencies further.

 

[Kingrex]

Don't go down the DC path please. No one is opening up their $300,000 worth of stereo equipment and modifying it.

The amps and preamps are mostly analog with a diode to make AC into DC and smoothing caps to clean the DC. The DAC and Servers are generally a linear PS. Some of the less expensive gear uses SMPS.

All people using battery inverter power supplies ranging from Goal Zero to Exeltech to Victron use a power conditioner on the load of the inverter. They say it helps.

My concern is the distorted sine wave when any inverters I have seen a scope tracking the wave have. Non seem to hold together at all. Not like the power from an outlet in a wall that seems far more tollerant.

I am looking for the highest quality inverter that runs a pure sine wave under load. Not a optimum bench test rating.

 

[robbob2112]

So don't drive the inverters so hard - they all distort pretty bad at 100% usage - but many of the LF inverters have a sweet spot around 60~80% where the THD is pretty small. Just get more inverters to supply your power in the sweet spot.

 

[Kingrex]

So don't drive the inverters so hard - they all distort pretty bad at 100% usage - but many of the LF inverters have a sweet spot around 60~80% where the THD is pretty small. Just get more inverters to supply your power in the sweet spot.

I notice this on video when properly loaded. Like a 2000 watt inverter and a 1400 watt heater. The images I have seen show jaged edges up the wave sides and usually the leading edge of the peak is flattering.

I would load the inverter to about 30% max. Add more as needed, or go up to a wall mount unit.

What are the cleanest, low distortion low frequency pure sine inverters? Is Victron really the best?

 

[rhino]

I notice this on video when properly loaded. Like a 2000 watt inverter and a 1400 watt heater. The images I have seen show jaged edges up the wave sides and usually the leading edge of the peak is flattering.

I would load the inverter to about 30% max. Add more as needed, or go up to a wall mount unit.

What are the cleanest, low distortion low frequency pure sine inverters? Is Victron really the best?

I'd wonder about a MorningStar SureSine inverter. They go up to 2500W.

 

[tinyt]

This will probably work. But this is only half of the solution. Use the noisy inverter to drive a motor, make the motor drive this generator, use one phase or re-wire your audio equipment ac-dc rectifier circuit to use all 3 phases. Shield all power wirings, also use non-metallic rotary drive couplings if you are still paranoid.
Edit: Generator mounting should also be electrically isolated from the motor mounting/inverter.

 

[Kingrex]

There's a name for isolated power systems that are motor to motor. The issue is, how good is the generating. motor.

 

[robbob2112]

Have you looked at the schneider 6848 pro series of inverters? They are pricey but they can put out either 120 single phase or 240 split phase.

6800watts output is the normal and they can surge to 12000w for 10 seconds or 8500w for 30 minutes. I watched a video on them yesterday with an O'scope across the signal while put into overload and the waveform didn't change in the slightest.

I am talking about this

Conext XW Pro 6.8kW 120/240 Volt Inverter 48V Charger

Note: Please look at our 865-6848-21 Schneider kits, you will find a 10-20% discounted system with these kits. NAZ-Schneider-XW-Pro-007 NAZ-Schneider-XW-Pro-008

www.solar-electric.com

It takes a insight home control to configure it for anything beyond basic operation and lead acid batteries, but that can be turned off once configured.

Looks like the rated distortion is less than 5% under load.




it IS very heavy and MUST be wall mounted - it has cooling from bottom to top that needs to be vented. This is a low frequency inverter and has a huge torid coil in it.

 

[Mops9]

I have been spinning around this for a while. Digging into spec and watching video. I am powering Audio Video equipment. I need a very clean sine wave. It has to handle very quick transient peak. You know, subwoofers demanding current. The sine wave can in no way clip the tops as I have heard of $100,000 amplifiers fry their circuits from clipped sine waves.

So hear is the issue. Even though companies advertise low frequency inverters as pure sine wave, the wave is disgusting. Especially under load. All but Victron advertise 10% harmonic distortion. When video show tbem loaded, the sine wave are incredibly chopped, spiked. They look more like 30% to 40% distorted. Even the Victron inverters look pretty bad.

I was ignoring high frequency inverters as their sine waves seem to completely collapse under load. But I'm wondering about an Exeltech XP2000. They claim their sine wave wont distort more than 2% if you load it under 2000 watts.
Does anyone know if any video ha e been posted of a XP2000 where a fluke scopemeter is attached to the Exeltech and the wave monitored under various loads.

First, if your 100k amp is that fragile, I am not sure how good it is....a good amp should have a robust and clean AC section..

I am to buy a XP2000 to put it to the test myself, but here is a video.

From what I read, there is no cleaner or better Inverter than Exeltech. No wonder, its made in Texas

Also, the way I spec the system, the Inverter will run between 20% to max 45% of its limit....

 

[Hedges]

The inverter waveform he shows does look clean, vs. utility grid has some distortion.
Grid would be through isolation transformers, possibly they introduce distortion. And grid is loaded.
He didn't say if inverter was loaded. Not a fair comparison if unloaded.

24V inverter and 48V inverter will be sharing battery bank.
He did not go into how that will be charged. Needs to be at least one 24V charger, of course. Probably two; I don't think 24V + 48V charger would work out right.

 

[andreimtl]

Low frequency = larger transformer.

The fet switching rate is lower because the winding of the larger transformer takes longer to charge up to the given voltage it wants to see at that time point in 60 HZ ac sine wave.

How do you know if an inverter is low frequency? I see in specs the frequency mentioned as 120V 60Hz - is that it?

 

[Checkthisout]

How do you know if an inverter is low frequency? I see in specs the frequency mentioned as 120V 60Hz - is that it?

No. It's on the DC side and you have to take the manufacturers word for it. It doesn't mean anything anymore anyways.

 

[andreimtl]

It doesn't mean anything anymore anyways.

Why?

I got on this rabbit hole because someone said here 5 years ago that Giandel is high frequency. And I also heard WP recommended them as good. I'm just about learning about these specs of inverters.

Btw, if you don't mind, what are some bettter budget brands these days?

PS: I'm looking at a Giandel 3kW. Thinking I'm gonna do max 2500W with that. Most likely 300-400 daily and 1000W once in a while.

 

[JonMez]

Absolutely concur with this.

My take is that if you are going to be pushing your inverter near it’s rated limits and you have inductive loads, LF is probably the better option.

But if you greatly oversizing the inverter capacity for actual demand and have a per-leg rating that easily exceeds the surge of any inductive load, there is little/no difference (other than the lower cost of HF inverters).

The Schneider Conext SW 4048 can deliver 3800W continuous and up to 7000W for 5 seconds. Maximum imbalance is not clearly spelled out but is almost certainly under 100% (cannot deliver only 7000W of peak power to a single leg). The 41A peak current would translate to no more than 4920W to a single leg regardless of whether 100% imbalance is supported or not.

The Conext SW 4048 costs over $1700.

Contrast that with this dual-HF alternative SRNE inverter rebadged by Y&H costing the same or less: https://www.amazon.com/Inverter-Split-Phase-Single-phase-Connection-Activation/dp/B0BMWVNKXK/ref=mp_s_a_1_16_sspa?adgrpid=121814000615&hvadid=517156367718&hvdev=m&hvlocphy=9032079&hvnetw=g&hvqmt=b&hvrand=12865543203528407712&hvtargid=kwd-343958467673&hydadcr=13085_9594469&keywords=240v+split+phase+inverter&qid=1685988415&sr=8-16-spons&ufe=app_do:amzn1.fos.17f26c18-b61b-4ce9-8a28-de351f41cffb&psc=1&spLa=ZW5jcnlwdGVkUXVhbGlmaWVyPUEyWUZQVDFCTjQ2TFNCJmVuY3J5cHRlZElkPUEwMDcyOTc0M0NJWVBLWUZOUEg0TCZlbmNyeXB0ZWRBZElkPUEwMjI1MTI0Mk9WM1Y2TURVTjVHSCZ3aWRnZXROYW1lPXNwX3Bob25lX3NlYXJjaF9hdGZfbmV4dCZhY3Rpb249Y2xpY2tSZWRpcmVjdCZkb05vdExvZ0NsaWNrPXRydWU=

5kW per leg sustained and 10kW per leg surge capability (with no issue supporting 100% imbalance).

The Conext SW4048 weighs 62 lbs while the Y&H 10K weighs 46lbs.

Don’t get me wrong - I realize a Schneider inverter is an entirely different class of quality and reliability than an SRNE inverter rebadged by Y&H so a large portion of this ‘equal’ pricing needs to be allocated to that and for the same price, the Conext SW4048 is probably the better buy.

But this illustrates my point: the dual-HF option can surge to more than twice the power of the Schneider LF alternative and can also sustain 232% as much power.

If you need more than what the Conext SW 4048 can deliver, you will need to pay more for it.

The Conext XW 6048 costs about double the price of the Conext SW 4048 and weighs 126lbs.

The XW 6048 can deliver 6000W continuous (still less than the Y&H) and can surge to 12,000W for 15 seconds (still less than the Y&H) but supports a L-N surge current of up to 105A = 12,600W which is 126% of the SRNE dual-HF peak current capability.

But for that you will pay about twice as much and have a LF inverter weighing almost 3 times as much.

10% off Black Friday … plus shipping

 

[fuzzmunky415]

10% off Black Friday … plus shipping

So I'd need the InsightHome with this and I'm good?

 

[JonMez]

So I'd need the InsightHome with this and I'm good?

That’s my understanding. Naz has great customer service for asking questions. I got the xw pro when it was $900 but haven’t set it up yet. It’s still a deal at 1100 for the specs. Not chepa to ship tho

 

[fuzzmunky415]

That’s my understanding. Naz has great customer service for asking questions. I got the xw pro when it was $900 but haven’t set it up yet. It’s still a deal at 1100 for the specs. Not chepa to ship tho

I should have done the XW Pro, but I had other expenditures (roof, washer and HPdryer, HPWH, Beast battery...) but snoozed, then I want a Little Rosie. This small kit would do my studio and maybe more for under $1K.

Yow. 62# for 4048, #15 for Little Rosie..

 

[ConnerLabs]

How do you know if an inverter is low frequency? I see in specs the frequency mentioned as 120V 60Hz - is that it?

Size and weight. The LF ones are always big and heavy for their power rating.

Have you seen the bumper sticker, “EG4 Owners Do It With High Frequency”

 

[andreimtl]

Size and weight. The LF ones are always big and heavy for their power rating.

Have you seen the bumper sticker, “EG4 Owners Do It With High Frequency”

But there has to be an actual frequency spec???

And no, I haven't heard that quote. Too new to this. I learned about the EG4 AIO just a couple of days ago.

 

[MattiFin]

But there has to be an actual frequency spec???

You need to take one apart to know if the internal design is HF or LF. Typically this is not specified or advertised as it is not necessarily so important point. (Weight is good indicator but you could also get HF inverter with very heavy case.)
Typical LF inverter is at minimum 7-10kg per kW.

Both have same 120v 60Hz output specification.