Making a vacuum pump from a fridge compressor

[splott]

I have a fridge freezer compressor which i am going to turn into a vacuum pump it has a mains electrical wire coming from it, another wire with two thin copper wires and a 3rd wire with 4 wires in the sleeve, i have been told that i will need to bypass the regulator for the compressor to work, can anyone give me information on how i can do this thanks

[The Viking]

If you intend to use it as a vacc pump within our industry, then the answer is NO...
Can't do the job, nowhere near enough suck from it.

[chemi-cool]

But.............. you can make a great bicycle pump from it

[keepitcool]

What oil should be used for the bicycle application?:D

[chemi-cool]

Sawing machines oil is the best.

[The Viking]

Oh yes,
Don't get me wrong...

I even re-sprayed a car utilising an old "fridge" compressor once.

But a vacc pump it ain't.

[Brian_UK]

I have a fridge freezer compressor which i am going to turn into a vacuum pump it has a mains electrical wire coming from it, another wire with two thin copper wires and a 3rd wire with 4 wires in the sleeve, i have been told that i will need to bypass the regulator for the compressor to work, can anyone give me information on how i can do this thanksWhat is the regulator ?

Also, before we all jump on you from on high - what service is this low grade vacuum pump wanted for?

Even better, can you tell us which make and model of compressor it is, you could even find the wiring diagram on the manufacturers' website.

[sacha35]

I have made these in the past and yes they do work, by running two of them together this will pull down to a vacuum, will it be enough for refrigeration well yes and no it all depends on the ambient temperatures that you are vacuuming in and the time you given the temperature.

To be honest your best bet is to buy a proper vacuum pump this will be more efficient and save you a lot of time and trouble.

[Brian_UK]

I have made these in the past and yes they do work, by running two of them together this will pull down to a vacuum, will it be enough for refrigeration well yes and no it all depends on the ambient temperatures that you are vacuuming in and the time you given the temperature.

To be honest your best bet is to buy a proper vacuum pump this will be more efficient and save you a lot of time and trouble.That is the only part to read and accept.

The NO part is the honest answer here.

Unless you can reach low micron readings then you have not achieved a good vacuum for refrigerants.

[Athanatos]

make an air compressor from it

[GXMPLX]

I have a fridge freezer compressor which i am going to turn into a vacuum pump ...

What all these fine gentlemen told you before me is true.


...

Sacha35 you made the same mistake I usually do if you probably use Word2007 or a similar lousy program to type, and when you copy and paste the font tags that RE pages do not understand.

Your second mistake is that you think you ever made a good vacuum pump! If you had done one it would immediately short circuit the fusite terminals for they are not insulated inside the compressor and would produce an arch in deep vacuum! You see they rely on the refrigerant dielectric resistance which is much higher than deep vacuum.

If you don’t believe me, please use a vacuum pump not made by you, pull 500 micron or better vacuum in it and then energize it while in vacuum.

The only good compressor I know did this where the first generation of scrolls from Copeland that didn’t have the floating seal! If you closed the suction valve the fusite would short circuit and burn!

Get one of those 20 year old compressors, open it, insulate the inner connections reassemble, add a check and valve and you have a perfect very expensive vacuum pump!

[The MG Pony]

I have a vac pump & it sucks! I use the fridge compressor to ruff the work peice then let the real vac pump to finnish the job!

you can get a 1.5cfm one at your door step for 200 bucks from ebay with a nominal vac of 38 microns, been using it for a while now and blanked off I get to 45 Microns in seconds!

[star882]

An old compressor can be made into a recovery unit, however.

[casstrig]

You can make a low grade vacumn pump from a compressor by cutting open and conecting the suction conection directly to the pump and the discharge pipe from the should be cut making the crankcase positively pressurised.the body can be sealed by flanging it and using a rubber gasket.this was a exersize I did as an apprentice and does work.

[pendlesteve]

Don't even think about it.
It's a compressor.
A vacuum pump is for creating vacuums.
It makes me wonder about the capabilities of some on this forum.

[TRASH101]

It's a compressor.
A vacuum pump is for creating vacuums.


Why not ?

Is the compressor not a pump.
Assuming he does it safely with due diligence then I don`t see a problem.



It makes me wonder about the capabilities of some on this forum.


Is that not a little harsh. Engineering does not have to be a formal dinner with dress restrictions;)

Its more the meat and potatoes of everyday life and my only concerns are for that of safety and good working practices.

[casstrig]

please note all you critics there is certainly nothing unsafe in the instructions I gave also note that my appreticship was with general electric,and at that time I was with their subsidary company Kirby Techumsie in Sydney Australia.
The fact that you dont know how to acheive this only means you lack knowledge,and your failure to accept knowledge means you are stuborn.

[keepitcool]

A shop vac can also be used as a low grade vacuum pump. That does not mean it should be used as a refrigeration system vac pump. If you are doing this to gain knowledge or just to experiment go for it. Just don't use it for the real thing.

[paul_h]

Why not ?

Is the compressor not a pump.
Assuming he does it safely with due diligence then I don`t see a problem.



Is that not a little harsh. Engineering does not have to be a formal dinner with dress restrictions;)

Its more the meat and potatoes of everyday life and my only concerns are for that of safety and good working practices.It's threads like these that made me give up on these forums for a while. Humouring every DIY'er that thought they could go cheap on methods and gear. Or seeing the same threads over and over again, either bumped 1+ years later after the question is answered, or seeing the endless samsung option codes/fridge fault finding (or hotpoint, or daikin/pana/fuji)
Anyway to answer your question:
Why not?
Because industry standard is 500-700 microns, you can't get that out of a recip compressor! It's even lower for refrigeration systems.
Engineering is not a formal dinner, and I'm a long way from calling myself an engineer.
But the right tools for the job is even something a 'mechanic' like myself knows there's no substitute for.
You might as well not bother with an evac at all, just run your reclaimer to vacuum, change the drier and she "she'll be right mate, the drier will take care of the rest".
There's more to this industry than working safely. It's about working for a living, enjoying what you do, and having some sort of pride in it.
People that take short cuts, do the wrong thing and give the trade a bad name through shoddy workmanship annoys me. It makes my job harder through government intervention and having to work hard at PR with customers to convince them I'm not a dodgey backyarder when I quote for jobs like all these other cowboys.

[Gary]

Back in the covered wagon days, when I first started in the trade, we used fridge compressors for vacuum pumps, because real vacuum pumps were rare, expensive and very heavy.

Did it work? Yes.

Did it work as well as a real vacuum pump? No.

Standard practice was to triple evacuate, because a single evacuation didn't do the job. (BTW, I still triple evac and highly recommend it.)

In this day and age, there is no conceivable reason to not get a real vacuum pump. They are light, cheap and sooooo much better.

[kiwireeferman]

I also started when vacuum pumps were rare.

We used a rotary compressor with the triple evacution method
A rotary by design will pull a lot higher vacuum. The one we used was the "Frigidaire metermiser"

Great days!