AC question

The A/C runs on the same principle of compressing and expanding of some refrigerant fluid; the difference is that the Prius compressor runs off electricity.

 

Following is the presentation material about the AC.
http://www.epa.gov/cpd/Presentations/Matsunaga electric inverter.pdf

Ken@Japan

 

The AC compressor is located low on the engine on the passenger (right) side as if it was belt driven, but there is no belt. The belt drives the water pump on the Gen 2 Prius, on the Gen 3 Prius, there is no belt as the water pump is electrically driven as well.

 

Yes the compressor on a Gen2 & 3 are driven by an internal 3 phase motor the supply being delivered by the DC/DC inverter, hence the orange wires going to it.
It is of the scroll type so there are no reciprocating pistons as you would find in a similar unit on an ICE powered car.

The unit uses R134a refrigerant as you would find in most cars on the road. HOWEVER' due to the inherent problem of moisture in A/C systems the lubrication medium mixed with the refrigerant CANNOT be PAG synthetic oil as it absorbes moisture commonly used in "other" systems.
So the hybrid manufactures use POG oil, this lube absorbes much less moisture. As we know moisture can cause shorting down, so shorting of a three phase system (even running at a lower voltage than the traction motors) will cause an A/C shut down if the HVAC ecm "sees" a fault.
Of particular concern is the Independant A/C shop or careless dealer that charges the system using the shop everyday recovery machine.
Since there will always be some "carry over" of PAG oil during charging , the internals of the Hybrid system can be contaminated with this recovered absorbent PAG oil.

For this reason alone we have a dedicated recovery/recharge machine when servicing hybrids like the Prius in my shop.

As for running and charging the A/C the scroll compressor tends to run continuously unlike the ICE mounted compressor which is driven by the serp belt and pulses on and off according to A/C demand.
On the hybrid the HVAC ECM modifies the a/c speed and characteristics by controlling the three phase internal motor.
Hope that uncovers some mysteries
Actros

 

A/C Question

Today the Air Conditioner icon at upper left of the 'Climate' screen lit up and stayed on. Sorry to ask a foolish question, but the car is now due for a periodic 5,000 mile service. If this "A/C - On" condition persists, will it cause difficulty to any systems? Thank you.

CTdane

 

That icon does not directly relate to the AC compressor. It means that the Heating/Cooling system is set on fully automatic.

For example, manually setting the fan speed shuts the icon off even if the AC compressor is running. The automatic system will not run the compressor unless the temperature (or humidity?) in the cabin is too high for external air to lower it sufficiently.

JeffD

 

You can turn ac in screen menu auto/off . It comes on automatically with climate. This can be disabled. We like using vents when not too hot. Although all the temps are controlled automatically, I prefer it not to turn ac on unless I tell it. It does remember last setting as well.

 

Um, you realize that you are responding to post from over 10 years ago?

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