need advice about A/C unit repair

[briansmith77]

I am a HVAC install mechanic that hasn't worked in the field in a few years and I'm in aposition where I have to repair a couple units. I never was a service tech, hopefully someone can help. The units are simple straight A/C with no thermostat. On the first one, the red wire to the capacitor in the outdoor unit keeps frying off. I replace it, but in a couple days it just fries off again. Obviously drawing too much current. What could the problem be?

On the second unit, the compressor turns on for about 5-10 seconds then cuts right back off again. The unit only has a suction port so I cn only read the low pressure side but the gauge is in the retard when I put it on. What are the options with that one?

Thanks for any help I can get.

[allan38]

When wire burns off of a capacitor it is typically due to corrosion inside of the wire bundle causing excessive resistance. A poor quality crimp, loose terminal, rusty terminal, overheated metal or undersized wire are among causes of high resistance in subsequent repairs.


There can be several issues that can cause the suction line to be in retard.
In any case, putting your gauges on a line while it is in retard will pull the air from your hoses into the refrigerant circuit. You may now have refrigerant contaminated with air and moisture.

You're asking a pretty basic question. I know much you can forget when you've been out of a trade for a while. I know there are all sorts of nooks and crannies in the trade where people never use certain parts of their training.

It is most likely low on refrigerant or has a restriction in the refrigerant circuit. It could both with poor air flow too. Neglected equipment frequently develops problems until one of them snowballs into a failure. I can't tell from here.

How to drill down and determine which one and what tools and techniques to use are beyond the scope of this area. At this point I have told my own out of town brother to call a professional.

[jnsrose]

There can be several issues that can cause the suction line to be in retard.
In any case, putting your gauges on a line while it is in retard will pull the air from your hoses into the refrigerant circuit. You may now have refrigerant contaminated with air and moisture.


How is this possible? Unit with suction line in retard usually means over pressure not under. Me thinks you got problems.

[Texas-Tech]

How is this possible? Unit with suction line in retard usually means over pressure not under. Me thinks you got problems.

Do you think he means retard or below 0psig? I was thinking he meant the latter at first but who knows.

[coilcleaner]

Your compressor could be overcharged or slugging, windings could be pulling high amps indicating limited life. You could have a restriction in system causing all of the above.

[coilcleaner]

The suction gauge starts retarding at about 100 pds. The other end would be called a vacuum.

[Texas-Tech]

Being he is not a service tech I may assume that he is mixed up on what his gauge is telling him. Guess we will have to wait and see.

[knave]

i hate it when my gauges say "RETARD!"!!!!!

[coilcleaner]

i hate it when my gauges say "RETARD!"!!!!!

You know you did something wrong when your gauges call you a retard.

[Glennhvac]

I have not gotten past the no thermostat part yet.

[coilcleaner]

Maybe he meant a duct t-stat or a high side cut out or something. I don't think he'z coming back.

[hvacvegas]

I have not gotten past the no thermostat part yet.

Interestingly enough.....

I stopped reading his post after I saw that.

[ncboston]

I have not gotten past the no thermostat part yet.

I caught that aslo.