How did you get evap coil 46deg, thermometer inserted into coil?
Let me know if Im wrong.
Evap superheat is 50deg minus 36deg, 16deg evap superheat.
Condensing temp is approx 132deg minus 72deg liq line temp, total subcooling 60deg.
Air in 53deg minus 36deg boiling point, 17deg temp difference.
4 deg drop across evap coil.
My first impression is metering device is starving evap. Head pressure is a bit high also but it might be dirty or high ambient. I would suggest looking at expansion valve adjustment/replacement and checking/cleaning condensor coil both.
Originally posted by ucp R12
34psi = 36deg
185psi= 132deg
My first impression is metering device is starving evap. Head pressure is a bit high also but it might be dirty or high ambient. I would suggest looking at expansion valve adjustment/replacement and checking/cleaning condensor coil both.
If TXV was starving coil suction would be low not high. If you want to maintain regular cooler temps with R-12 you need at least an 18# suction. Check the chart.
P.S. another random thought. High discharge might be another indicator of bad compressor not dirty condenser. Broken disch valves will reduce refirerant flow thus high suction, but cause an awful lost of heat to be passes to the high side due to disch gas entering and leaving cylinder with broken valves. Lots of heat generated but no refrigerant flow. Thus the high subcooling. Focus on the compressor.
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If TXV was starving coil suction would be low not high. If you want to maintain regular cooler temps with R-12 you need at least an 18# suction. Check the chart. [/B]
Your right, I think we all are trying to get him there.
ucp-yes, 1st thing after I walk in, jab temp probe in coil.
Evap & Cond coils already clean.
pumped down last night.........didn`t bypass lp cutout....shutdown at 5#
It`s better to be silent and thought the fool; than speak and remove all doubt.
Issue not resolved yet.
Compressor pulls down to 20" vac.
Haven`t spent much time on this box, we can`t seem to get there until midafternoon--------that bites, guy comes in at 8:00 every morning.
This unit also has an intermittent high head trip out.
I was really hoping the condenser would not pump down.
It`s better to be silent and thought the fool; than speak and remove all doubt.
Is this a new customer? Have you or your guys worked on the box before? Are you sure you have R12? Could you have non-condensables in the line or a mix of refrigerant? It acts like it has 22 in it with a 12 power element.
What size TXP? and is it an R12 head? With a blend like R414B (Hotshot) your superheat says you are starving the coil. How is the sight glass? Full or bubble?
It`s better to be silent and thought the fool; than speak and remove all doubt. 
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