17.Verify Variable Frequency Drive setpoints for VAV unit Supply Fan and optional Variable Frequency Drive Exhaust and/or Return Fan drives. The Sup- ply Fan VFD is located to the right of the electrical control box in the supply fan blower compartment. Refer to separate manual for VFD operation sup- plied with the unit.
18. If equipped, open suction line ball valve, discharge line ball valve, and liquid line ball valve for each refrigerant system.
UNIT CHECKS – POWER APPLIED
1.Apply
2.Verify programmed units Setpoints (refer to “Quick
3.Verify correct fan rotation – fan should rotate in direction of arrow on fan housing.
4.Insure proper compressor rotation - see following instruction on Verifying Compressor Rotation.
Verifying Compressor Rotation
This unit uses scroll compressors, which will only operate in one di- rection. Failure to observe these steps could lead to compressor failure.
FORM
The eco2 rooftop unit uses hermetic scroll compressors, which only pump in one direction. Therefore, it is necessary to verify proper rotation at unit
To verify proper rotation, monitor the suction and discharge pressures of the respective refrigerant circuit when the compressor cycles on. If the discharge pressure increases and suction pressure decreases as the compressor cycles on, the compressor is properly phased and operating in the correct rotation.
Compressor Oil Level Check | 3 |
The oil level can only be tested when the compressor is running in stabilized conditions, to ensure that there is no liquid refrigerant in the lower shell of the compressor. When the compressor is running in stabilized conditions, the oil level must be between 1/2 and 3/4 in the oil sight glass. Note: at shutdown, the oil level can fall to the bottom limit of the oil sight glass.
JOHNSON CONTROLS | 49 |
