Dunnair ducted problems please help

[daveo222]

I have 1 Dunnair split Ducted AC that keeps tripping out on head pressure, It will only trip very occassionaly and not necessarily on hot days.

System is single stage R22 with Externaly equalised TXV.
when I am on site i cannot find a problem with the unit

Suction pressure is 439KPA 63PSI
Liquid Line pressure is 669KPA 97PSI
Disharge Pressure is 200PSI
superheat is 9.5 Celcius 17 degrees Farenheight
liquid Line temp at exit of condensor is 16 degress Celcius 60.6 farenheight
ambient temp is 28 degrees celcius
Room temp is 22.5 Degrees
Compressor Amps are L1 14.3A L2 13A L3 13.6A
Compressor Voltage is L1 256V L2 256V L3 256V
Condensor TD is 8.4Degrees Celcius

Any help would be appreciated as i cannot solve this problem.

Thanks in advance

[Brian_UK]

Is this unit cooling only or is it a heat pump?

[daveo222]

Its a heat pump unit but is doing it while cooling

[cool_tech]

Hello
I had a similar problem where at 27 degc ac units would cut out. they were slightly overcharged. and the hp/lp on those units might not be set right. set them correctly using your gauges and nitrogen.

[jason09]

you must be taking liquid line temp and pressure after metering device!

[goshen]

Hi
i think Brian was pointing you in the wright direction,possible fast change from cooling to heating,and viceversa could cause this hp cut out,
i would also check as mentioned your presostats ,and condenser fans.
good luck