Air dryer fault

[paul441]

Hi
Have got atlas copco air dryer tripping out on hp,condenser clean, has electronic hbpv on it could this be my problem as its restricting gas flow, would be gratefull for any advice.
unit takes r404a 4.5kg cheers

[chemi-cool]

Had the same problem on Atlas Copco some time ago, I just replaced the refrigerant and all was well afterwards.
Charge it with 507, its more stable, and pressures and temps are close enough.

[paul441]

hi chemi-cool
had leak on this unit about 6 months ago and put fresh charge in then, when i called atlas they say take soleniod off as they have as its restricting flow but i cant work out why this has not happened in past cos dryer has been on site for 2 year cheers mate.