Over charged system

[jakb21599]

Hello friends, I know that an under charged system will cause the evaporator to freeze up. But is it possible for an over charged sytem to cause the evaporator to freeze up ? Thanks for your input.

[nike123]

OVER CHARGE = Low superheat. Normal indoor heat exchanger TD. Higher than normal suction pressure, subcooling, head pressure & compressor current draw.
Evaporator will freeze if you have evaporator fin temperature below 0°C. Rate of ice formation will depend on air flow and humidity, no matter if overcharged or not, if evaporator fin temperature is below 0°C.
Since we expect higher suction pressure, ice formation could be somewhat lower in comparison with correctly charged system.

[Tayters]

I wouldn't have thought the evaporator would freeze up because although having more refrigerant in it, it would be at the same or higher saturated temp/pressure therefore same or higher evaporator temperature.
The only thing that might start freezing would be the suction line and compressor.

Cheers,
Andy.

[mikeref]

Tayters, a small capillary system will flood back with overcharge, well.. anything using cap really, but tx system overcharge (depends on how much % over it is), will still work as per normal untill Reciever fills up, then condenser backs up etc. BTW, time to get out of the dog house. The woofer wants its home back;).. Mike.

[Magoo]

A faulty TX valve will create a frosted coil and system will appear overcharged, liquid stacked in high side

[mikeref]

Hey Magoo, good point there! Wonder if origional poster meant frosted over partially, as in say 1/3 coil or fully.. In which case it may have nothing to do with gas charge. High heat load/humidity/lack of defrost time/too cold, etc.

[Magoo]

Hi Mikeref.
With a full feed from TXV as in no distributor you can get the front face fully frosted, with a distributor generally get weird frost pattons on front face and through coil. Counter flow air to refrig of course.
What should be flashing in evap is stacked in condenser.
magoo

[Tayters]

Tayters, a small capillary system will flood back with overcharge, well.. anything using cap really, but tx system overcharge (depends on how much % over it is), will still work as per normal untill Reciever fills up, then condenser backs up etc. BTW, time to get out of the dog house. The woofer wants its home back;).. Mike.

Sorry Mike, I stand corrected. I had my blinkers on that day and had capillary in my mind when I wrote that. No other form of expansion device had entered into my thinking then.
I remember blokes filling up supermarket packs with a good dollop of refrigerant when they couldn't find a leak and wanted it to last a while so it looked like it sprang another leak after they had repaired a leaky 'schrader'...

Out the doghouse. Moved into the Sin Bin!

Cheers,
Andy.

[old gas bottle]

think its easier to just remove the gas and recharge it,you know thats right then,if it persists then start looking into possible causes.

[mikeref]

Hey Tayters, we all get thoes days, no drama though. Waiting to hear from OP, only been a few days. I see the doghouse is where you'll stay for now:p, couldn't stop laughing when i read your request for help today:D...Mike.