Compressor activated the High Pressure pipe to the condenser gets hot and can be seen to pressurise.

The outlet pipe from the condenser is cold, I have disconnected the fans for test purposes.

Pressure sensor is on the High Pressure pipe after the Condenser.


When the compressor is engaged the Pressure sensor and my independent gauges will go from 7 bar to 1 bar ??

I think I have a blockage some where between the condenser and the Pressure Sensor ??

Any help greatly appreciated

Yes, looks like. Odd isn’t it. Might be ice. Happens when pipes are left open and driving in the rain.

Yes, looks like. Odd isn’t it.

Hi Liviu
I am not so sure but I will ask the question as the customer (Mitsubishi Technical Uk) is asking me !!

Could this be the expansion valve ??

My thinking is that a blocked expansion valve would give me too high a a pressure on the High Side and Very Low on the Low Side.

If it is broken and open - My thinking is that pressure would be equal on both Hi and Lo but not go as low as 1 bar when charge pressure is near 7 bar ??

What are your thoughts ?

Hi.
.
If the filter-dryer is blocked in the air conditioner system, then both high and low pressure lines become gas suction lines.
In this case, when the compressor is triggered, instead of increasing the pressure, a decrease will occur.
All this is true, provided the nominal amount of gas in the system.

Hello,
Use a thermal camera to find the point of phase changing(where the parts of AC become frozen).Too much oil added in system,the moisture trapped when the system is left open for a long time will block your dryer filter.
Best regards