Excavator a/c
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H8theheat
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- Joined: Fri Apr 03, 2020 3:37 pm
Re: Excavator a/c
Just out of curiosity what would be an acceptable vent temp it's 85 or so right now and I just want it to be able to keep up when it's 95.
Re: Excavator a/c
Thank you for all of the help
Re: Excavator a/c
In any mobile system anything above 33f is good for discharge air. As long as you can keep the evaporator from building up ice you are good.
Here in the dry air of Las Vegas I run a second switch with a very low setpoint for quick cooldown. Evaporator temps fall below 30f, but at 8% humidity & 115f ambient this is not a problem.
With the hysteresis in CCOT systems you can run an average evaporator temperature of 33f without ice buildup. With a TXV system the evaporator temperature sensor handles the job. Just make sure that at it's lowest setting, with the cabin fan on lowest speed that ice formation is not an issue.
A19 apparently is an HVAC guy. This is MVAC. If you can hold your hand in front of a vent and make your knuckles hurt the system is working well. That is why there is a temperature dial and fan speeds.
Here in the dry air of Las Vegas I run a second switch with a very low setpoint for quick cooldown. Evaporator temps fall below 30f, but at 8% humidity & 115f ambient this is not a problem.
With the hysteresis in CCOT systems you can run an average evaporator temperature of 33f without ice buildup. With a TXV system the evaporator temperature sensor handles the job. Just make sure that at it's lowest setting, with the cabin fan on lowest speed that ice formation is not an issue.
A19 apparently is an HVAC guy. This is MVAC. If you can hold your hand in front of a vent and make your knuckles hurt the system is working well. That is why there is a temperature dial and fan speeds.
Re: Excavator a/c
Alright I'm back and I have the same problem. I have replaced the expansion valve again and I still cannot get colder than 49-52 out of the vent..I cleaned the evaporator again so air flow is not an issue...one thing I am wondering about is the little sensor on the evaporator I think it is called a frost sensor or an evaporator sensor, what exactly does it do and where on the evaporator should it mount ?
Things done so far
Heater valves are shut
Ac lines Flushed
New compressor with right amount of correct oil and weight of refrigerant (30 oz )
New drier
Expansion valve replaced twice
Evaporator fins cleaned and installed new filter
Condenser fins cleaned
It's 87 outside and in the cab it's 78-80
Things done so far
Heater valves are shut
Ac lines Flushed
New compressor with right amount of correct oil and weight of refrigerant (30 oz )
New drier
Expansion valve replaced twice
Evaporator fins cleaned and installed new filter
Condenser fins cleaned
It's 87 outside and in the cab it's 78-80
Re: Excavator a/c
Remove the sensor from the evaporator and let it hang loose. Does the vent temps go lower? It is very possible the sensor is bad. Was the compressor new ?
Added info: I realize getting to the sensor may be a bear. Try this first. Run a wire from the compressor clutch connection to the inside of the cab. Connect a meter or small lamp to lead and ground. If the light stays on, it is probably not the sensor. You may not have a refrigeration issue but a control issue.
Added info: I realize getting to the sensor may be a bear. Try this first. Run a wire from the compressor clutch connection to the inside of the cab. Connect a meter or small lamp to lead and ground. If the light stays on, it is probably not the sensor. You may not have a refrigeration issue but a control issue.