TABLE TOP FRIDGE

[GEOFF]

I have two table top (Russell hobbs) fridge that I intend to use in my Maxus conversions. Reading the various comments that I have read on this site It would appear that a pure sine wave inverter must be used to run it on 12V. I am fairly sure that the motor will run on a poorly smoothed supply - are the fridge electronics really unable to operate using one of the cheaper inverters? If the answer to that question is yes, would it be possible to add some form of waveform improver? I know that we do have a couple of electronics Gurus on here and would be very interested to hear from someone. The reason for my posting is that I do have a couple of cheap Chinese 1500w inverters that I would like to use. Geoff.

 

[SquirrellCook]

I suspect an oversize cheep inverter will happily start and run your fridge. But if Sod’s law got involved and both fridges tried to start at the same time it might be another story.

 

[GEOFF]

Thanks for the reply. I only want to run one fridge, I am converting 3 Maxus vans!!! Anyway I will give it a try. My reason for posting was in case I might damage the fridge.Geoff.

 

[Squiffy]

Geoff, I have over the years used modified inverters for all sorts of applications, including computers, the only item I ever had problems with was a tooth brush charger that ceased to work after it had been on charge for a period of time, it could just as easily been a faulty charger I don't know for sure. You hear of all sorts of doom and the sky will fall in if you use modified wave inverters, I feel that Squirrel is right that the main point is to use a much higher rated inverter than required for the job especially if starting heavy duty AC motors. I have to also say that in the past I admit I have put my money where my mouth is on several occasions by trying a suck it and see
With some expensive equipment. Anything that goes through a 230v to 12/24/36 or 48v dc charger/transformer will have no issues, but don't take my word for it check it out on the worldwide where there are many electronic buffs and (manufacturers of inverters)who say that in general, modified wave is all that is necessary other than for highly sophisticated electronic equipment.

Other than folks reading up on this subject
themselves, I take no responsibility if anyone fry's their pride and joy, it's an experiment that I have done and not had to regret. Phil

 

[GEOFF]

Thanks Phil - as I said I will give it a go. Geoff.

 

[wildebus]

I think a QSW Inverter will work fine on a basic fridge. But it won't work as well or as efficiently.
The cost of Pure Sine Wave Inverters over the Quasi/Modified Sine Wave Inverters is not that great at the lower power units, so the extra money for the better product is not that great.

Last comment and this may be subjective and feel free to have an alternate opinion ... When you are talking about an inverter for a fridge your are talking about a device that you will be leaving on 24/7, a device that you will leave unattended for long periods, a device you will be leaving running when you are sleeping. So you want something that is built up to a quality, not down to a minimal price. 'Nuff said.

 

[Squiffy]

So you want something that is built up to a quality, not down to a minimal price. 'Nuff said.

This is very pertinent advice, but ofcourse this is just as relevant for Full sine wave models, and there are just as many Full sine waves models out there that are just as economically produced as Modified sine wave and could be just as likely to fail, it's a fact of modern life that there is a certain amount of trust that the item you have purchased will stand up to expectations. Phil

 

[wildebus]

This is very pertinent advice, but ofcourse this is just as relevant for Full sine wave models, and there are just as many Full sine waves models out there that are just as economically produced as Modified sine wave and could be just as likely to fail, it's a fact of modern life that there is a certain amount of trust that the item you have purchased will stand up to expectations. Phil

But generally the cheapest kit tends to be the ones with the lowest features - so MSW rather than PSW.

Also there are a lot of PSW inverters out there for sale that are NOT PSW Inverters. They are blatently missold, in exactly the same way with "MPPT" Solar Controllers found on eBay that are very basic PWM Controllers. And the sellers can do this because they know many people don't really understand what they are getting, they just look for words and chose the cheapest product that includes those words; plus few buyers of these products, whether they understand what they are looking for or not, actually have a way to confirm they are getting what they believe they have bought. How many people here if they were presented with a "Pure Sine Wave" Inverter could check it was really a PSW Inverter or a misrepresented MSW Inverter?

I am not knocking buying cheap where appropriate - a few months ago I bought the cheapest 500W inverter I could find on Amazon with next day delivery as I wanted it fast and for a project where quality didn't matter. It turned out to be a very decent product, but corners were certainly cut. The croc clips it came with had undersized cable attached and the clips themselves you could bend with your little finger (they went straight in the bin). If that is what is visible, what other bits were under-specified internally which you couldn't see? There is no way I would use that inverter - or any comparable ones - unattended for hours and hours.
you say "certain amount of trust that the item you have purchased will stand up to expectations " - well, if buying at bargain basement prices I would say that I have a 'certain amount of trust that the item you have purchased will stand up to expectations that it will fail'

But as I say, each to their own, and everyone is free to buy what they want, and in the same way I will buy (and specify for my customers) what I want

 

[Squiffy]

Dave I do believe that was my sentiment, that many pure waves are also built with economically produced componants unfortunately the vast amount of electronics are now produced in China or Malaysia all be it under a European company license
Ten or fifteen years ago they did produce electronic components that seemed to fail on a regular basis, but they have improved over the years to the point where European countries source their components from there, so if folk really want to purchase definitely top notch equipment they would have to do some very deep research on the company that produces such items, as to A) where their product is manufactured and B ) what quality and country the electronic components were produced. But good luck on getting an honest answer to that one. Phil
P.s. My son works for a well known American company that deals in electronic wizardry items, they claim that you can only purchase this (Item) from them that it is all American made and American reliability, the truth is the same (Item) in Shenzhen is packaged in a different case of a different colour and badged under a different name, but is sold in the UK and other countries at a 1/3rd of the price of the American addition, this has been happening for many other products for years, the only real way to know is to strip the item out of it's case and check the component quality.

 

[GEOFF]

Thanks for the various comments.The reason that I posted was to hear what forum members thought about the MSW inverters and if they work without damaging the fridge. I have bought many items from China I and have had very few pre few problems, and must say that on the couple of occasions when there has been something wrong it has always been very quickly sorted (probably quicker than some UK suppliers). I must say that for my own use running the fridge via the inverter is generally limited to whilst driving or having a "picnic" as we only ever use sites with HU and never wild camp. For that reason I personally only fit 85AH leisure batteries. Geoff.