Power vs. Compressor speed - graphs inside
 

We are producing some custom cooling system in vehicles (R134a used), which needs to cool relatively big ammount of air (about 3-4 m3/sec).

Now we have some problems: as we increase the compressor speed, the cooling power doesn't increase too much, so we think that some part in the system is somehow saturated. I have measured some data (air cooling and compressor pressures) with various compressor speeds, which are displyed below. Can some professional say what component could be weak in the system just by looking into these graphs?

http://www.volny.cz/veitel/cooling.gif

Thank you,
Petr

Re: Power vs. Compressor speed - graphs inside
 

I was just going over compressor troubleshooting this morning, for my car (am going over an R134A conversion).

Let me re-read it again tonight, and I'll have an answer for you tmo.

Re: Power vs. Compressor speed - graphs inside
 

Thanks.

Is the troubleshooting available in an electronic form? I would be also interested to read it.

Re: Power vs. Compressor speed - graphs inside
 

The info comes from my car's factory service manual. It is in print.

I believe that you can buy service manuals on eBay for just about any car, but I don't know wether or not they include AC troubleshooting to this extent.

I'll try to copy then scan some pages, but this is going to take me several days.

In the mean time...

Taking the data from the charts:
1650 rpm
High side pressure
13 bar @ 21 C
15 bar @ 27 C
14.5 bar @ 32 C
15 bar @ 38 C

Low side pressure
3 bar @ 21 C
3.3 bar @ 27 C
3.5 bar @ 32 C
3.5 bar @ 38 C

The readings at 21 C suggest a refrigerant overcharge.

The readings at 27 C, 32 C, and 38 C look normal

PM me an email address that can take large files.