DAIKIN Help High Pressure

[Bakerbj]

RP125L7W1 Model

Customer rang me on saturday night, I got there only two find an E03 error message ( high Pressure ) put the gauges on, 10 Bar. Switched it off, left it for half an hour, switch on after 30 seconds it fired up, then after 2 minute the fans cut out, the pressure then built up from 3 bar, back to 10 bar. and shut off.

It is a 3 phase system

Any ideas ?

[frank]

Is this in heating mode or cooling?

10bar = 150psig so this should not trip the HP.

[Bakerbj]

in cooling. I spoke to Daikin and they wasnt to sure why the fans would cut off after 2 minutes. They did suggest they because it is 407, a blend that it might have a leak and some 134 has leaked leaving 410, ( now quite sure if I heard right, but i understand what they ment ) So I will take it all out and pressure test and recharge, but on this system there is a pump down reset button, do i need to use this ???

[Bakerbj]

The problem also is that i went back today and it was not giving an error code ? When I press test to see the last error message it comes up E0 but it did have E03 before ?

[Jase]

At which point are you taking the gauge reading?
Are you reading the pressure @ the 3/8" s/o valve (liquid line)? If so, then find the high pressure access hiding behind the electrics.
As for the high pressure fault, you state that the fans switch off. Check the thermistor readings. If the thermistors resistance values are not good then the fans will cut off and hence system will trip out.

Regards
Jase

[Bakerbj]

how do i check the thermistor readings ????

[refaircon]

sensor for fan??
fan relay??
fan??

any more info, does anything else happen??

[coolments]

Hi Baker

We have had trouble with these units, I assume its a suction reading you have took. We have found suction strainers just before the compressor have been crumbling inside causing a restriction and generating pressure faults and E0 as the compressor over heats and cuts out on its clixon.

The compressor is sucking its self silly but you dont see it as the service port is before the strainer.

Could be that, try it we have cut loads out,replaced with a section of pipe then had no problems after, let me know.

[puddleboy3]

Im pretty sure this unit doesnt control head pressure from the actual head pressure. Outdoor fans are controlled by the ambient thermistor on the back of the unit. Also I wouldnt expect a high pressure trip with a blocked suction strainer but hey Ive been wrong before!!!!!

[Jase]

how do i check the thermistor readings ????

Get yourself a temperatutre/resistance chart. You will probably find it in a Daikin service manual.
Check the thermistor with your meter on a Kilo-ohm scale.For instance if the ambient temp is 20oC when checking the thermistor, just check the chart and you will find a resistance reading which corresponds to that ambient.

Regards
Jase