There is only two types of compressors

Techman

from the view point of the compressor motor,that is. Say what?

Harvey Ramer

The ones that turn and the ones that don't?

bob_46

not sure of your question ? I would say positive displacement and centrifugal .

unclejohn

Then from the compressors point of view there's only two types of motors.

Techman

The two types of compressors is as follows from the view point of the comp motor.But first a little info, the comp motor produces heat, that heat has to be removed from the motor or else the motor overheats and whackado,another comp bites to bullet. So the 1st type of comp is the "Suction Cooled " comp where the heat from the motor is eliminated by the cool returning suction gasses passing over the windings of the motor.This happens in all AC systems and in most medium temp refrigeration systems.Now keep in mind that the lower the suction pressure the lower the density of the freon and that lower density freon carries less molecules of "comp motor cooling freon", so, the "magic line" of the 2nd type of comp is at 0* evap temp.That is freezer compressors and only the rarest of medium temp comps. The 2nd type of comp (motor)is the "air cooled" comp. This means that the cond fan motor HAS TO BE ON ALL THE TIME THE COMP IS RUNNING, for air impingement to be blowing on the comp body to cool off the comp motor.So ,no cond fan cycling control or motor master type of device is allowed. This is related to the "Killing A Compressor"thread.

Harvey Ramer

There is one more. Daikin I believe, uses compressor discharge to cool the motor.

Techman

Oh yeah, in AC any "semi hermetic" that has the suction service valve bolted to the side of the comp ,right by the comp head , is an air cooled comp.

Empire_2

Terry I guess I will take a stab at. RECIPROCATING, OR ROTARY.

ChrisJ

I'm confused by the question?

Even in the GE Monitor Top there's two different kinds.

1927-1932 uses reciprocating
1933-34 uses a weird oscillating rotary pump
1935-1938 uses a scotch-yoke reciprocating type.


Here is a video of the oscillating rotary being turned by hand. I've yet to see this design anywhere else.

http://youtu.be/gn0u7dFBCTk

Same pump running with the fan visible.

http://youtu.be/bfkNLHy9nkw


Besides that, you have scroll type, rotary vane and a few others, no?

Or is that not the question?

From the motor's view I'd say they are all slightly different. I can't see that oscillating rotary being the same as a reciprocating pump.

SWEI

It's almost like a scroll compressor with only one turn.

Techman

This thread was started because of another thread in which the freezer comp was being killed by the use of a cond fan cycling control. The motor in the freezer comp gets hot and is cooled off by the air from the cond fan motor hitting onto the comp body. During the fall,winter,spring on windy days the cond fan motor can be off for the entire comp on cycle. I see lots of freezers w/ cond fan cycling , or motor rpm controllers. That don't make it right. I make 'em right.

ChrisJ

Shouldn't most if not all of the compressor's cooling come from cool vapor from the suction line?

My neighbor's fridge is dying and he told me he has no complaints as he got his moneys worth because it's 15 years old. I told him to get back to me when it hits 80.

bob_46

I think the main difference between your frig and your neighbors is. Yours new was $300 and a new full size Ford was $385 and your neighbors was $1000 to $1500 and a new full size Ford is
$25000 plus . There was a lot more quality built into your GE .

ChrisJ

bob said:

I think the main difference between your frig and your neighbors is. Yours new was $300 and a new full size Ford was $385 and your neighbors was $1000 to $1500 and a new full size Ford is
$25000 plus . There was a lot more quality built into your GE .

True,
But you would think over a period of 65 years some improvements could've been made in cost vs quality. The only thing that has improved is size, weight and the power factor of the compressor.


So back on topic. Aren't most compressors cooled mainly by return vapor?

Don_197

Most are.............even the semi hermetics above. Open drive compressors are air-cooled. http://en.wikipedia.org/wiki/Vapor-compression_refrigeration

bob_46

That's an awfully broad question. In general recip, rotary, scroll and centrifugal can be hermetic or semi hermetic in which case they are cooled by suction vapor they run from 1/4 to about 1500 tons. Recip , screw and centrifugal can also be open i.e. the motor or steam turbine is separate from the compressor and are not cooled by suction vapor . The biggest I have worked on is 7000 ton steam driven. I have never seen a compressor cooled by the condenser fan .

Techman

All "suction cooled" compressors have the comp motor cooled off that way. The cool suction gas is passed over the motor windings, cooling the windings. This group includes all "regular" residential/commercial AC , some commercial AC has the cool suction gas go directly into the comp suction intake and NOT going over the comp windings, which means that the comp motor is an "air cooled" comp.Any/All comps operating at 0*f evap temp or lower require "air impingement" on the comp body to cool off the comp motor.

pecmsg

R-134A Liquid cooled windings
400- Ton Cintrif

pecmsg

Centrifugal

ChrisJ

I wish I had a "condenser water supply" pipe in my basement....


That's not sarcasm.

pecmsg

ChrisJ said:

I wish I had a "condenser water supply" pipe in my basement....


That's not sarcasm.

I wish i had trhe basement

BTW
2400 Volt on that motor

ChrisJ

I don't see much need for 2400 volt in my house.
440 3 phase would be handy though.

NYplumber

Techman said:

All "suction cooled" compressors have the comp motor cooled off that way. The cool suction gas is passed over the motor windings, cooling the windings. This group includes all "regular" residential/commercial AC , some commercial AC has the cool suction gas go directly into the comp suction intake and NOT going over the comp windings, which means that the comp motor is an "air cooled" comp.Any/All comps operating at 0*f evap temp or lower require "air impingement" on the comp body to cool off the comp motor.

Good info Techman. Thanks for the post!