Carrier 30HXC Low Oil Pressure Fault

[Taaz1275]

Hi Guys, apart from a defective oil solenoid or oil pump to a blocked external, internal oil filter. what could be other causes leading up to a low oil pressure fault?
And if the oil has migrated to another part of the circuit (evap/shell and tube), what is causing this migration?
Thank you.

[seanf]

Low suction superheat letting liquid back to the comp?

Slightly low on refrigerant charge causing poor oil return?

Fault with economiser expansion valve, not giving enough flow and building oil in the heat exchanger? If it has one.

Damaged oil separator?

System running at low cooling capacity for extended periods?

System short cycling?