Trane CITY RTSF Series Manual page 35

Unit Voltage Phasing
It is important that proper rotation of the compressors be established before the unit is started. Proper motor
rotation requires confi rmation of the electrical phase sequence of the power supply. The motor is internally
connected for clockwise rotation with the incoming power supply phases A-B-C.
When rotation is clockwise, the phase sequence is usually called "ABC" , when counterclockwise "CBA" This direction
may be reversed by interchanging any two of the line wires.
1. Stop the unit from TD7/UC800.
2. Open the electrical disconnect or circuit protection switch that provides line power to the line power terminal
block(s) in the starter panel (or to the unit mounted disconnect).
3. Connect the phase-sequence indicator leads to the line power terminal bloc (L1, L2, L3).
4. Turn power on by closing the unit supply-power fused-disconnect switch.
5. Read the phase sequence on the indicator. The ABC LED of the phase indicator will glow.
WARNING! It is imperative that L1, L2, and L3 in the starter be connected in the A-BC phase sequence to prevent
equipment damage due to reverse rotation.
WARNING! To prevent injury or death due to electrocution, take extreme care when performing service procedures
with electrical power energized.
CAUTION! Do not interchange any load leads that are from the unit contactors or the motor terminals. Doing so may
damage the equipment.
Water System Flow Rates
Establish a balanced chilled-water fl ow through the evaporator. The fl ow rates should be between the minimum and
maximum values given on the pressure drop curves.
Water System Pressure Drop
Measure the water-pressure drop through the evaporator on the fi eld installed pressure taps on the system water
piping. Use the same gauge for each measurement. Do not include valves, strainers, or fi ttings in the pressure
drop readings.
RLC-SVX023B-GB
Pre-Start Checkout
35