For Booster Unit
The amount of oil to charge in the system depends on several factors (length and size of liquid line and suction lines, speed of refrigerant flow inside the pipe, size of receiver, …).
Compressors are pre charged of oil by the manufacturer and the Oil Reserve IS NOT pre charged by SCM.
Typically the reserve oil has 2 sight glasses and it should be pre-charged before starting up the unit with POE Oil up to cover the higher sight glass.
Level of Oil must be monitored during the commissioning.
In case the level of oil decreases below the higher level during the first day of operation, it is suggested to fill some extra oil to increase the level above the higher level again.