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aupanner
11-08-2010, 10:42 PM
I am needing help match up compresser duty. The old compresser is a semi hermetic 1/3 hp running at 1750 rpm giving 2.37 m3ph. I want to fit a hermetic compresser but they are sized up in cm3 displacement but do not say what their rpm is. Do all hermetics run at the same speed or are there different speeds?

powell
12-08-2010, 03:54 AM
I am needing help match up compresser duty. The old compresser is a semi hermetic 1/3 hp running at 1750 rpm giving 2.37 m3ph. I want to fit a hermetic compresser but they are sized up in cm3 displacement but do not say what their rpm is. Do all hermetics run at the same speed or are there different speeds?

I cant speak for all brands but Copeland hermetics run at 3400 rpm.

Do you have the model number of the semi?

Snowflake
12-08-2010, 04:36 AM
As you long as the displacements the same, the refrigeration duty etc are the same, you should be fine irrelevant of what type of compressor you use.

nike123
12-08-2010, 05:07 AM
I am needing help match up compresser duty. The old compresser is a semi hermetic 1/3 hp running at 1750 rpm giving 2.37 m3ph. I want to fit a hermetic compresser but they are sized up in cm3 displacement but do not say what their rpm is. Do all hermetics run at the same speed or are there different speeds?

Displacement is volume in time. It cannot be expressed as cm3. That is only volume.
Usual units are:
m^3/h
ccm (cubic centimeter per minute) or cm^3/min
in^3/min (cubic inch per minute)
cm^3/revolution
etc...
As long as you correctly convert these units you are safe.