Carrier xarios 300

[imes]

Hello i have problem with the carrier xarios 300. Display shows me an error p01 and p20. Can someone tell me where i can find service manual, so i could fix the problem, or if anyone knows how to fix the problem could you help me?
Thank you

[abbsnowman]

The alarms with "P" in front represent "Past alarms.
The P01 is "past low pressure". The P20 is "past micro low pressure jumper open."
If you have present alarms, they would read with an "A" in front of a number.
If you send me an email, I will see if I can email you a manual.
mark@futureclimates.ca

[thefridgeman2]

Ao1 is lp switch open on engine
a20 is lp switch open on standby

both alarms can be caused by

1 a faulty lp switch
2 blocked expansion valve

pump unit down replace drier clean out expansion valve orifice.