Low or high frequency inverter

[Frugal Devonian]

My LF does the heavy lifting and has done faultlessly for six years,I think I read somewhere they are better in rough conditions too, humidity,dust etc.

 

[Daddy Tanuki]

My LF does the heavy lifting and has done faultlessly for six years,I think I read somewhere they are better in rough conditions too, humidity,dust etc.

I have several LF's and 3 HF's. one of the LF is a magnum 2012 it now has 12+ years of faultless service powering a fridge and basic amenities in a camper which runs 24-7.
I have a total of 4 four, 4448's two which are currently running the other two are in storage awaiting a problem. the two that are running are from 2016 and 2018 the spares are varied.
Zero issues to date other than a lightening strike casualty. i also have two sigineer 5k unit for water heating, and one samlex 500 watt unit running as an aux for the camper

the above being said, zero functional issue with the LF's zero functional issues with the HF which are backups. so it is what it is.

 

[fatjay]

It’s almost always cheaper to reduce loads than increase solar production. I did the same thing here. Went to a heat pump water heater, put in a high seer heat pump mini split and a pellet stove. When we bought the house, it only had electric baseboard heat and a conventional electric water heater. My first electric bill in November of 2013 was $600.

Heat pump is the next move. When I first bought my house in 2008 I went through a tank of oil a month, when oil was ~5/gal. That was over $1000/mo in oil for 4 months. I learned to get my wood stove in order for the next season, but also did a full clean of the furnace, and replaced the leaky single pane windows. Lots of sealing up on other stuff too, makes a huge difference.

 

[fatjay]

yep its that one world order... all of those Masons, Scottish Rite, York Rite and Shriner's... they be pulling those levers of power...

or maybe it is just a bunch of overly powerful industrial conglomerates figuring out who to pay in the government to get their hooks set properly so they can fleece you.

My local masonic chapter didn't get the memo, they're all bitching about the price fixing as well.

There are to many moving parts, it's hard to imagine one group has taht much control, other groups would fight back.

 

[Daddy Tanuki]

My local masonic chapter didn't get the memo, they're all bitching about the price fixing as well.

There are to many moving parts, it's hard to imagine one group has taht much control, other groups would fight back.

oh there are always corporate conglomerates with that much control... microsoft is a perfect example.

 

[quantum`]

My local masonic chapter didn't get the memo, they're all bitching about the price fixing as well.

+1 Brother.

 

[Daddy Tanuki]

+1 Brother.

W C U?

 

[westcoaststank]

i did the same in regards to loads... being wood heated the next step was to eliminate that... as I get older the ability to split 10 or 12 cords would obviously decrease, even with a hydraulic wood splitter... first it was LED lights, then more of the newer LED lights. this had a surprising effect as event he original LED lights compared to incandescent s were amazing the. the 2nd gen LED were magic. everything after that was replace as it dies until I had for Japan anyways the best that could be had... jsut to find out it was pretty much a joke here anyways. BS marketing ploys and actual measurements made me shake my head. many of the older gear was just as efficient over 20 or 30 days. day to dy maybe not , but overall yeah... and they lasted longer. I have since slowly retrofitted with gear that is both efficient and long lived... do not let the siren song of false efficiency tkae your coin, as thats all it is sometimes a game to get your wealth.

what kind of efficient things, like lights etc... would you recommend ?

 

[ksmithaz1]

Ah OK, that makes a lot of sense. Fully off grid or dislike using any Grid, got it. The chargeverter threw me, was thinking you might be using grid to charge only.

If the SOC falls below 12 the CV cuts on. off at 15%. I use the genny relay in the 18kpv to knock a small ats and power it on from the grid. It is set to minimal voltage, max 80A/4KW. Big robust ATS is slow, if it all falls over it will kick in. I managed to produce 142KWH yesterday, still hit 100% SOC by 1430. Charged up car from 2% to 75, mined $3 worth of bitcoin, did some baking, and took a long hot shower. Might have issues this summer when the HVAC runs all night. We shall see.

 

[ksmithaz1]

oh there are always corporate conglomerates with that much control... microsoft is a perfect example.

Same could be said for IBM at one point.

 

[Gttnsun]

What idle numbers do you speak of? How is any idle power draw going to have any effect on a properly designed system? I people talk this irrelevant stupidity all the time. If you need to push 240v@28a you are not going to engineer for 6720w exactly of capacity, unless you are a blathering idiot. 100w would represent 1.6% more capacity than your load. Insignificant.

It's not irrelevant stupidity if you live off grid. 100 watts×24 hours is 2.4kwh per day.
Plan for 7 days of rainy weather that is 16.8 kwh of extra battery needed.
Properly designed? Get ready to shell out another $4k for batteries

 

[Daddy Tanuki]

what kind of efficient things, like lights etc... would you recommend ?

Too long did not read? go to the bottom For BLUF

first of all, every single lighting fixture should be filled with the newest LED's think about it in my 900ish sqft cabin it has a grand total of (wait for it).... 24 light fixtures... if all of them have a bulb that uses 60 watts (they do not I have floodlights on the exterior as well) and even half of them are on thats 720 watts. all of them?1440 watts by replacing them all with led bulbs I am now down to about 240 watts if I leave them all on. thats a huge difference.

my AC split pack is a high efficiency mitsubishi i could not tell you the model IRT US models (remember Japan) but it is super efficient, variable speed compressor, and it is also mounted under the house out of direct sunlight. it keeps the entire cabin/cottage comfortable at 20-25°c for an average of 300 watts 24/7 from april to november. at that point in time it is up to the wood stove or kerosene stove to keep it warm.

fridge and freezer are both smaller than you would normally see in the US as Japanese (the Tyrant that is my wife) shops daily for fresh food so you do not need a huge refrigerator. only reason we have a freezer is for wild game, and my purchasing jaunts to either costco, or the closest base for Beef and Pork.

that being said both are very efficient. the freezer does not have auto defrost as that as huge waste of electricity, the fridge's auto defrost is programable and I simply shut it off. manually defrost every once in a while and save a lot of watts in the process.

the biggest waste of energy in the place is the Hori Kotatsu it is a heated table over a well or pit that your legs sit in and has a blanket draped over the table to retain trap heat. most japanese do not heat the entire house as this is wastful, instead they work to make certain often used areas pleasant and ignore the rest. sleeping quarters: cold, get blankets and comforters, toilet cold (heated toilet seats popped up here int he 60's for a reason) things like that. so the Hori Kotatsu has two 1800 watt heaters built in and you can vary the temp etc. since the remodeling and new insulation etc. the kotatsu's power requirements have dropped to about 10% over the initial cost of use.

I ran the entire shop and cabin off of one 4400 watt LF magnum for 6 years with zero issues. it is easier to save power than to make it. I now run two as I have expanded some items in the shop which require more power, but the magnum master/slave setup totally shuts off the second inverter until the primary reaches a preset % in my case I set it at 70% as that allows me to run hosue and shop generally speaking on one inverter. only when I fire up the large overhead lights does the second inverter kick in and then its primed for the heavy tools.

the more power you use, the larger your battery bank and panel system need to be to meet your day to day and your extended bad weather needs. even small drains like an inverter with high idle load.. that high idle load doe not go away when youa re powering other things, it still exists.. so if you inverter uses 60 watt idle power with no load then when you put a 100 watt load on it, it is now using 160 watts.. not one hundred

it is cheaper to save, then to produce.

 

[ksmithaz1]

It's not irrelevant stupidity if you live off grid. 100 watts×24 hours is 2.4kwh per day.
Plan for 7 days of rainy weather that is 16.8 kwh of extra battery needed.
Properly designed? Get ready to shell out another $4k for batteries

Sorry, it's still irrelevant, because overhead is still overhead and the operational current of your inverter is simple overhead. There is no magic bullet, all these systems have some sort of drain, the percentage goes down the larger the inverter, and the overall loss from an HF vs an LF is much lower. If you want to live off-grid and have a 7 day reserve from your solar batteries . . . Let's look at my situation. At the moment I can get by with say 40KWH (That would be aggressively low) per day. Thus assuming some maximal gloom where I managed to get nothing I need 40x7 = 280KWH of batteries to last the week. And you are concerned about another 17KW? I think you just want a generator, not more batteries for an extended outage. If you are worrying about the operating current for your inverter you missed the mark on your engineering the overall percentage is nominal.

Thus I stand by my statement. It's all about demand, if you occasionally need 80A at 240v you need more inverter or life is going to be a shell game. If you want to be dumb, you better be tough. Buy as much battery as makes sense to handle the 90+% case, use a genny to make up the difference.

 

[ksmithaz1]

so by more products to make you HF inverter act somewhat like a LF inverter... Got it...

Disingenuous,. Your 4K LF inverter is not going to run a 5K load. If I get two 6K LF's now maybe I can start and run my load, but of course I'm going to be limited to about 50A/240v. OTOH, if I get 2x12000xp's, not only can I start and run the 5K load, but I have 75A of overhead for other high current items, like EV chargers, Hot water heaters, clothes dryer's.

The game is always covering demand, thus, based on your argument: if my demand gets as high as 100A I need either 4x6KW LF's or 2x12KW HF's. Last time I checked 4 > 2. YMMV.

 

[SparkyJJO]

Or you can get a 18000W LF (with 54kW for 20 seconds surge ability) for around $3k and then "all" you'll need to do is cover its ~300W (7.2kWh/day) overhead.

Never ever have a problem starting up everything at the same time, but will cost you in batteries and solar to power the darn thing!

 

[Gttnsun]

Sorry, it's still irrelevant, because overhead is still overhead and the operational current of your inverter is simple overhead. There is no magic bullet, all these systems have some sort of drain, the percentage goes down the larger the inverter, and the overall loss from an HF vs an LF is much lower. If you want to live off-grid and have a 7 day reserve from your solar batteries . . . Let's look at my situation. At the moment I can get by with say 40KWH (That would be aggressively low) per day. Thus assuming some maximal gloom where I managed to get nothing I need 40x7 = 280KWH of batteries to last the week. And you are concerned about another 17KW? I think you just want a generator, not more batteries for an extended outage. If you are worrying about the operating current for your inverter you missed the mark on your engineering the overall percentage is nominal.

Thus I stand by my statement. It's all about demand, if you occasionally need 80A at 240v you need more inverter or life is going to be a shell game. If you want to be dumb, you better be tough. Buy as much battery as makes sense to handle the 90+% case, use a genny to make up the difference.

It's not irrelevant, more overhead is more overhead. Living off grid you need a HF inverter that is twice the size of a LF inverter. That is double the idle draw.
It's very simple math, but it sounds like you have grid power so it doesn't matter to you.

 

[SparkyJJO]

"idle" draw (or rather, self-consumption as it isn't only there when idle) varies a lot by brand and model though. There are some HF inverters that have high self consumption higher than a good LF. Then there are others that don't, and two of the better HF may still not have that much draw. Example - my 8kw LF Outback Radian has a self-consumption of 34 watts, while a Voltronics lv6548 uses 70 watts. Part of that is because the Voltronics is an AIO so it has the MPPT integrated, while the Radian does not, but does the MPPT really account for all of it? Probably not. And the Radian will beat the ever-living snot out of the Voltronics. The Radian also costs more than the Voltronics.

My main point is that you can't make a blanket statement "LF vs HF idle consumption" because there's too many variables, and it is all a game of give-and-take.

 

[Gttnsun]

"idle" draw (or rather, self-consumption as it isn't only there when idle) varies a lot by brand and model though. There are some HF inverters that have high self consumption higher than a good LF. Then there are others that don't, and two of the better HF may still not have that much draw. Example - my 8kw LF Outback Radian has a self-consumption of 34 watts, while a Voltronics lv6548 uses 70 watts. Part of that is because the Voltronics is an AIO so it has the MPPT integrated, while the Radian does not, but does the MPPT really account for all of it? Probably not. And the Radian will beat the ever-living snot out of the Voltronics. The Radian also costs more than the Voltronics.

My main point is that you can't make a blanket statement "LF vs HF idle consumption" because there's too many variables, and it is all a game of give-and-take.

You are right, I don't know about every HF or LF, i have looked at specs of alot of HF and Low Frequency inverters and it seems like the idle draw is much higher on the HF

 

[ksmithaz1]

It's not irrelevant, more overhead is more overhead. Living off grid you need a HF inverter that is twice the size of a LF inverter. That is double the idle draw.
It's very simple math, but it sounds like you have grid power so it doesn't matter to you.

On balance an inverter 'box' is going to use some of the power you get in order to operate. If you are off-grid that power amount should not be relevant, since as a percentage of your total use it's very small. If your engineering a system with tolerances that tight you made a huge mistake. If you only need 3KW to run your load, you buy a single 3KW box, likely with ~30-40W of idle power draw, and it has a linear effect on battery consumption. If you want to last your mythical '7-days' you still need 6720WH. You act like two boxes takes 15000WH but one box takes ZERO. Doesn't work that way. To SparkyJJO's point, it's not cut and dry either. You take loss every single time you convert power from A to B.

The original comment was around getting an extra 'box' to make up for trying to start a 6700+ watt inductive load (240V/28A). The arguments seemed to be that a 4KW LF inverter is somehow going to start this load, for which I'm going to call BS. Or that a 6.8KW LF inverter is going to start and run it, which has not been demonstrated, and for which I believe to be doubtful, as it is frankly too close to the limit just to run it much less start it. At this point you are WAY, WAY, WAY past worrying about a modest power drain from an extra box, since without an extra box you can't run your effing load.

Off-grid/On-grid/Looking at the grid . . . Equipment overhead is mostly irrelevant because any differences are nominal, you need enough inverter to meet the total demand of the system, or you may as well take your ball and go home. If you are off grid, you cannot guarantee sunshine, nor that any amount of battery is going to keep you from having a backup generator. Somehow we seem to think that there are some magic 30KWH batteries that will run your system for 7 days with no input/sunshine, but will be overburdened because of the 50-100W needed to run the system and create power. Your battery bank has to be sized to meet your consumption over the time period needed / pain threshold. Your inverters must be sized to meet your demand. If 50-100W is a significant portion of your demand/consumption when you are off-grid, you are probably not going to need to worry about it, since you don't need that much to begin with.

I'm not sure about the mythical LF inverter with zero overhead that will start a 6KW inductive load, and still run the rest of your stuff, using no battery, but I'm all in to see the YouTube video.

 

[SparkyJJO]

I'm not sure about the mythical LF inverter with zero overhead that will start a 6KW inductive load, and still run the rest of your stuff, using no battery, but I'm all in to see the YouTube video.

I'm gonna put it in the same category as the 'run your ICE car on water' idea.

 

[455dan]

Well I did see a post by another member with a LF transformer based Schneider XW Pro and says it started a 6 HP air compressor without any problem.
I asked for details in that thread: whether it is a belt drive vs. direct drive, whether it is a single stage or two stage pump along with motor details.

Lots of use going on right now so I can't separate out the 18K immediately and just power my garage with no other loads but LED lights and see if can start the air compressor as it's only load.

 

[Gttnsun]

Who said there was a LF inverter with no idle draw?
I also never saw anyone here claim to have a off grid system with no generator.

 

[Farm Boy]

More to add on the video above, versus my own test experience today with my air compressor.

Was wiring a disconnect input for the 18K from grid so the 18K can be taken out of the circuit, so it seemed like a good time to test whether the 18 K could handle the 80 gallon belt drive after being impressed by the video.

My results do not match the test they did above.

Had about a 3000 watt load on the 18K- with an additional 2KW coming in from PV, ( versus their 195 amps battery current draw already to support their existing loads with only one Power Pro, before they were able to successfully start the belt drive IR compressor)


I tried to start the 80 gallon two stage (6 hp start)- 5 HP running compressor and the compressor maybe rotated 1 revolution then Moaned and lights out.

The 18k shut down.

I immediately shut off the pressure switch on the compressor.

18K and lights came back up in about 5 seconds.


Now I have my answer, as far as ever running this compressor "Off Grid" without a soft start or adding another 18K PV the answer is no.

My compressor is a Quincy QT 5 and with a soft start from SS, will not start either, in fact it made it worse. Buying another 18kpv to run as a pair probably would start but switching to the grid at the shop I can do while still being off grid at the house, cheaper result.

 

[ksmithaz1]

Well I did see a post by another member with a LF transformer based Schneider XW Pro and says it started a 6 HP air compressor without any problem.
I asked for details in that thread: whether it is a belt drive vs. direct drive, whether it is a single stage or two stage pump along with motor details.

Lots of use going on right now so I can't separate out the 18K immediately and just power my garage with no other loads but LED lights and see if can start the air compressor as it's only load.

Air compressor? 6HP is a LOT of air compressor. 6HP motor is going to be borderline on that 18K. I'd put a soft-start on it.

 

[Brucey]

Disingenuous,. Your 4K LF inverter is not going to run a 5K load. If I get two 6K LF's now maybe I can start and run my load, but of course I'm going to be limited to about 50A/240v. OTOH, if I get 2x12000xp's, not only can I start and run the 5K load, but I have 75A of overhead for other high current items, like EV chargers, Hot water heaters, clothes dryer's.

The game is always covering demand, thus, based on your argument: if my demand gets as high as 100A I need either 4x6KW LF's or 2x12KW HF's. Last time I checked 4 > 2. YMMV.

Not sure about his magnums longer term output capabilities but here's the Schneider xw pro 6848: