INTRODUCTION

I was curious to see what was inside the compressor, and decided to use my electric filing machine to teardown the compressor, and show you guys, what its lime inside a burnout compressor.

Since the inception of hybrid vehicles in the automotive industry, almost all AC compressor assemblies fitted on hybrid cars, were belt driven. For instance, the first generation of Toyota Prius (1997-2003), were fitted with AC compressor assemblies, that were belt driven, and somewhat found in conventional vehicles.

But it was soon found out by Toyota, that using such compressor driven by the vehicle's accessories, wasn't measuring up with the sole purpose of such a vehicle, which was designed purposely for fuel economic reasons, and not for performance, so to say.

With this observations in mind, Toyota, in newer models of its lineup of hybrid cars, incorporated a more efficient compressor assembly. This time around, it was driven by an alternating current source, via an inverter/converter system.


So, today, I'm going to be talking about an electrically driven Prius AC compressor assembly I torn down, to have a glimpse what they comprised of, and why they fail.

What does the compressor comprises of?
Compressors commonly found on some hybrid and electric vehicles, are all driven NY alternating current source via an inverter assembly.

These compressors comprises of;
1. A stator. That's the casing or housing in which the electric motor resides(rotor).
See fig...

2. It has an inlet and exit port, just as is seen on conventional compressors.

3. It has an orange high voltage wire harness attached to it, from the inverter/converter assembly.

4. It uses a special kind of compressor oil.
Conventional cars uses ND8, while hybrid cars uses ND11(at least for Toyota brands).


WHY DO THESE COMPRESSORS FAIL?
The failure rates of these compressors, are low, compared to its counterparts. The reasons being that the materials compositions of the electric motors(windings, and insulations), have being improved, over the years.

BELOW ARE SOME OF THE REASONS THEY FAIL:
1. Use of substandard compressor oil. The use of wrong specifications of compressor oil, like ND8, would damage the compressor.

Here's how it does that: ND8 oil, has got no insulating properties in it; and as such, when used, it tends to compromise the insulations on the windings of the electric motors, thereby shorting the windings, resulting into what we call BURNOUTS. See figures below.

Using the right compressor oil (ND11), acts as a cooling and lubricating agents within the stator of the compressor.

2. Failing hybrid battery. Undersupplying the compressor motors with such voltages, would stress the winding insulations, and cause burnouts. This can be compared to what happens, for instance, when you turn on your refrigerator, if the power supply is less than the rated voltage. As long as the compressor of the refrigerator is exposed to such a low voltage situation for a long time, the compressor motor would burnout.

So, to protect the compressor, do not put on the AC system while the hybrid battery is not fully charged.

3. Cross contamination. Using the same recharge hose that has being used on a car that requires an ND8, would in the long run, cause a hybrid system AC compressor to fail. So, if you intend to recharge your hybrid compressor system, do not use or share the same hose with applications meant for conventional compressors.

4. Blocked condenser, or tubing. Blockage can always occur, if a condenser, or a tubing is blocked as a result of poorly done installations, or failed condenser.

HOW DO YOU KNOW THE COMPRESSOR IS FAULTY?
1. Suddenly, the AC system keeps blowing hot air, when turned on.

2. Intermittently works, when the system is recharged with gas

3. Sometimes, your hybrid battery would almost totally drain, because in rare occasions, the electric motor winding insulations has shorted out.


HOW DO YOU GET HYBRID SYSTEM SPECIFIC COMPRESSOR OIL?
You can get the oil, from any reputable stores online, or offline.

WHAT HAPPENS IF YOU ALREADY HAVE A DIFFERENT COMPRESSOR OIL APART FROM THE RECOMMENDED?

Ensure you get the entire AC system flushed of all the contaminants, and recharge with new gas and oil.



CONCLUSION
The costs of replacing a hybrid vehicle's compressor is tremendously much. It could rip a hole in your financial pocket.

Using the right compressor oil, and observing tail signs of potential failure, would narrow down what faults needs to be tackled.







Regards,
Joseph (calls/WhatsApp)
DW Nig Ltd
Isolo, Lagos
www.dxta.net.ng

Great job. Is it the same type of compressor used on the 2006 HiHy?

@mrtesso. Yes, they're all the same, with different voltage capacities.

The hihy is bigger, and does the same functions any hybrid or electric vehicle's AC compressor does.



Regards
Joseph