Genesis
Top Post Dawg
Well, the ALH has exactly one pressure sensor and its right in front of the TXV, effectively at the high-side service port. What did your gauges show when it happened?
When you're charging the charge goes into the system and pressure rises on both sides; when the high side (where the sensor is) reaches ~35-40 psi the unit will come on. I've having trouble seeing how the pressure goes *too low* to cause it to cycle back off on the high side after that point. It's real common on systems with two switches (e.g. most "cycling" units like those on American and Japanese cars) to cycle repeatedly until you get a decent charge in them because the low side switch will cycle it off under suction -- but the ALH doesn't have a low-side sensor.
The most-likely event that I can think of to cause that would be a (quite badly) plugged dryer, which would result in low pressure on the high side AND low side -- basically all the refrigerant is stuffed in the condenser and dryer. With a low charge that could lead to cycling but it also should lead to no cooling either
That condition is rather dangerous in that if the RCV was to stick closed (no bypass) you'd blow the relief valve on the compressor since the switch would not see the high pressure condition and would probably burn up the compressor too since there'd be very little refrigerant actually circulating and thus little cooling of the compressor itself.
When you're charging the charge goes into the system and pressure rises on both sides; when the high side (where the sensor is) reaches ~35-40 psi the unit will come on. I've having trouble seeing how the pressure goes *too low* to cause it to cycle back off on the high side after that point. It's real common on systems with two switches (e.g. most "cycling" units like those on American and Japanese cars) to cycle repeatedly until you get a decent charge in them because the low side switch will cycle it off under suction -- but the ALH doesn't have a low-side sensor.
The most-likely event that I can think of to cause that would be a (quite badly) plugged dryer, which would result in low pressure on the high side AND low side -- basically all the refrigerant is stuffed in the condenser and dryer. With a low charge that could lead to cycling but it also should lead to no cooling either
That condition is rather dangerous in that if the RCV was to stick closed (no bypass) you'd blow the relief valve on the compressor since the switch would not see the high pressure condition and would probably burn up the compressor too since there'd be very little refrigerant actually circulating and thus little cooling of the compressor itself.
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