Any suggestions??

Roy Tenn

Hi all,

I work in a housing complex where the condensing unit is
on the ground floor and the air handler is in the 3rd floor. The copper line sets are approx. 30 to 45 feet distance from the air handler to the condensing unit.
A lot of these units have defective compressors. I have changed a few compressors but not the whole condensing unit. The reason I was hesititant to change the condensing unit is the line sets are 3/8 and 5/8. and all condensing units take 3/4 and 3/8 pipe especially for such a long run. This is probably why the compressors went. It is IMPOSSIBLE to replace the line sets as it runs thru the inside 1st, 2nd, 3rd floor ceiling and walls. The housing complex is about 10-12 years old. The condensing units are 1.5 and 2 ton Skymark units (horizontal condenser fan air discharge). The air handler is a Enerzone with hot water coil. Any suggestions? What would happen if I just put in a regular Goodman condensing uint with the existing line sets? Thanks in advance.

Dick_3

YOUR PROBLEM MAY NOT BE RELATED TO THE 3/8 AND 5/8 LINE SETS; AND, 45 FEET IS NOT REALLY EXCESSIVE. MORE INFO. IS REQUIRED TO FIGURE OUT YOUR PROBPLEMS:

-WHAT'S THE PRESSURE DROP IN THE SUCTION PIPING FROM THE EVAP TO COND UNIT?
-WHAT'S YOUR SUCTION AND LIQUID PRESSURES?
-WHAT'S YOUR SUCTION AND DISCHARGE SUPERHEAT?
-WHAT'S YOUR SUBCOOLING?
-WHAT'S YOUR TD ACROSS THE EVAP COIL? COND COIL?
-DOES THE EQUIPMENT OPERATE BELOW 60 DEGREES OUTDOOR AIR TEMP?
-WHAT TYPE OF METERING DEVICE?

Eugene Silberstein 3

Thank You, ****!

It is impossible to troubleshoot a system properly without obtaining a COMPLETE set of temperature and pressure readings. As **** mentioned, these readings include:

Low side pressure

Evaporator saturation temperature

High side pressure

Condenser saturation temperature

Evaporator outlet temperature

Condenser outlet temperature

Return air temperature at the evaporator coil

Supply air temperature off the evaporator coil

Outside ambient conditions

Compressor discharge temperature

Refrigerant type

Metering device

Amperage draw of the compressor

RLA and FLA of the compressor

I hve had too many techicicians replace defective compressors and not resolve the issue of WHY DID THE COMPRESSOR FAIL IN THE FIRST PLACE? A loose TXV thermal bulb can lead to liquid floodback and result in compressor damage. If the compressor is replaced and the cause for failure is not found, you will be replacing too many compressors.

Try this... Keep asking yourself WHY. When you can no longer answer that question, you have probably found the inital cause for system failure. The efective compressor is just the result, not the problem.

Empire_2

lINE SIZE

I agree with ****, your line size is or seems to be OK,. 30 to 40 ft may require 3/4" line on siction side, but it should all be in your manual. Since the Evap is above the Condenser, no special trap consideration need be applied. Oil migration should be no problem as long as the system is charged correctly and remains as such through the years. Are your compressors suffering a short or a valve problem.??? Dont forget that when the temps are cooler, be it 60* or 45 at night, the ref. will tend to collect near the condenser and if cycled at start up you may be dead heading the compressor only for a short time, but it will eventually take it's toll on the unit. A pump down solenoid may solve all your problems.... Just a thought.
Thanks Mike T.

Mark Hunt

Thanks Prof!!!!!!!


And ****,

CAPITALS ARE CONSIDERED SCREAMING IN THE I-NET WORLD..

Turn off the CAPS!

Mark H

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Dick_3

What is I-NET world?

IN THE REAL WORLD CAPS ARE EASIER TO READ WHEN YOUR EYES START GOING. YOU'LL FIND OUT.

Jeff Lawrence_24

I-NET world

is shorthand for internet world.

****, if your eyes are that bad that caps are easier, either get better glasses or reset the font on your computer.

All caps can be hard to read.

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