Re: Fridge compressor for vacuum pump?

To: tesla-at-pupman-dot-com
Subject: Re: Fridge compressor for vacuum pump?
From: Alex Crow <user-at-alexcrow.clara-dot-net> (by way of Terry Fritz <twf-at-verinet-dot-com>)
Date: Fri, 02 Apr 1999 11:44:05 -0700
Approved: twf-at-verinet-dot-com

Jim

I don't know of the model, because the label has actually worn off - all i
can say is that it's from a big "Lec" chest freezer, and is quite heavy. When
I removed it lots of refrigerant evaporated, but I didn't lose any oil from
inside (well, maybe a drop when I turned it upside-down. When I said three
wires, I meant three 3-core L,N,E mains cables. Still havent opened the box
yet, but I get a feeling it's quite simple - one cable went to the light in
the lid, the other one disappeared somewhere under the base, and one which I
stupid;y forgot to label went to the mains plug!!

If i get a chance, I may test it tomorrow, see if it will boil water!

Alex

Tesla List wrote:

> Original Poster: Jim Lux <jimlux-at-jpl.nasa.gov>
>
> Tesla List wrote:
> >
> > Original Poster: Alex Crow <user-at-alexcrow.clara-dot-net>
> >
> > Dear All
> >
> > I just managed to rip out a compressor from an old freezer (doing my bit
> > for the ozone layer in the process!) and was wondering which bit sucked
> > and which blows - the big pipe at the top which went into the freezer or
> > the one at the back that went to the radiator? It's also got three mains
> > wires, but I haven't opened the junction box yet so maybe I'll work it
> > out then.
> >
> > Anyone used these as a vacuum pump before? what sort of performance can
> > I expect?
> >
> > Alex Crow
> big tube is in (low pressure), little tube is out (hot, high pressure)
> Probably a capacitor between two of the wires, power applied between
> two, and possibly a relay or something to switch the cap.
> The performance is highly variable in vacuum pump duty. Does the pump
> still have the oil in it? In a refrigerator or freezer, it is a nice
> closed system, and the relatively cool refrigerant coming from the
> evaporator (the cold coil) is also used to cool the motor of the
> compressor (cheaper, etc.). When using it as a vacuum pump, you may not
> get the same cooling effect. However, since it was free, if you burn it
> up, you've got yourself an education, so not all is lost. Don't forget
> to tell us what model it was, etc. so others can benefit from your
> fortune or mis fortune, as the case may be.