issues running a 2 ton compressor on a 1 1/2 ton cond. coil

[mo'parts]

Hello all, new here.
Just had a quick question, at work i have run into a couple condensing units (r22, residential) that have been previously "rebuilt" by, well, who knows. They have installed 2 ton compressors onto the existing 1.5 ton condensing coils.(pretty small ones at that)
Basically, there is no way to get these units to run even close to normal, correct?
Ok suction press and way high head press on the one unit, with close to "normal" readings on the other.
Both with only about 6-8* delta t at the A coils.
Unfortunately these are both on 3rd floor apts....
My Maintenance Supervisor has less knowledge than me on AC systems and has a hard time understanding that this setup will not work properly. Oh, one has a 2 ton A-coil and the other a 1.5, if it matters.
Am i correct here?
Thanks in advance.

Adam

[CPboy]

im also interested in this topic since my client asked me to replace a copeland scroll 2tonner compressor installed in a 1.5tonner tecumseh condenser, now since the compressor is already broken, i am inclined to replace it with a 2 ton hermetic piston compressor or use a 1/5ton piston compressor?

thanks also in advance for any comments or advise.

[abet_meneses]

definitely will not work,although the unit may run but will have a high head pressure
and, low suction pressure on the other hand equating to low cooling capacity and high power consumption.compresor will not last long.

[kssoin]

Hello all, new here.
Just had a quick question, at work i have run into a couple condensing units (r22, residential) that have been previously "rebuilt" by, well, who knows. They have installed 2 ton compressors onto the existing 1.5 ton condensing coils.(pretty small ones at that)
Basically, there is no way to get these units to run even close to normal, correct?
Ok suction press and way high head press on the one unit, with close to "normal" readings on the other.
Both with only about 6-8* delta t at the A coils.
Unfortunately these are both on 3rd floor apts....
My Maintenance Supervisor has less knowledge than me on AC systems and has a hard time understanding that this setup will not work properly. Oh, one has a 2 ton A-coil and the other a 1.5, if it matters.
Am i correct here?
Thanks in advance.

Adam

Hi Mo,parts,


These sysrems have a capillary and you will need to replace the capillary. Change the capillary as per the kcal/hr of the unit and subcooling (the limiting factor will be the condenser)
I have recently done a compressor replacement and did a cap change based on this rotary compressor manual.
You then charge this system to the subcooling and finish the charge at the target superheat.
You will find the formula for target superheat posted by Nike123 on this site.
Due to size limitations on this site i cannot post it here.
If you PM me your email id i will send you the attachment.

Forum mates is there a way to post the manual omn the forum?

Regards.
Kssoin