Trane RTHD

60 RTHD-SVX01D-EN
Installation Electrical
phase sequence or phase rotation. This is determined by the direction of rota-
tion of the alternator. When rotation is clockwise, phase sequence is usually
called “ABC,” when counterclockwise, “CBA.”
This direction may be reversed outside the alternator by interchanging any
two of the line wires. It is this possible interchange of wiring that makes a
phase sequence indicator necessary if the operator is to quickly determine
the phase rotation of the motor.
Correcting Improper Electrical Phase Sequence
Proper compressor motor electrical phasing can be quickly determined and
corrected before starting the unit. If using an Associated Research Model 45
Phase Sequence Indicator, follow this procedure:
1. Press the STOP button to insure the unit will not attempt to start the
compressor.
2. Open the electrical disconnect or circuit protection switch that provides
line power to the line power terminal block in the control panel (or to the
unit-mounted disconnect).
3. Connect the phase sequence indicator leads to the line power terminal
block (or the unit mounted disconnect) as follows:
4. Turn power on by closing the unit supply power disconnect switch.
5. Read the phase sequence on the indicator. The “ABC” indicator on the
face of the phase indicator will glow if phase is “ABC”.
 WARNING
Hazardous Voltage!
Disconnect all electric power, including remote disconnects and
discharge all motor start/run capacitors before servicing. Follow
proper lockout/tagout procedures to ensure the power cannot be
inadvertently energized. Verify with an appropriate voltmeter that
all capacitors have discharged. Failure to disconnect power and
discharge capacitors before servicing could result in death or
serious injury.
6. If the “CBA” indicator glows instead, open the unit main power discon-
nect and switch two line leads on the line power terminal block (or the
unit mounted disconnect). Reclose the main power disconnect and
recheck phasing.
7. Reopen the unit disconnect and disconnect the phase indicator.
Phase Seq. Lead 1TB1 Terminal
Black (Phase A) L1
Red (Phase B) L2
Yellow (Phase C) L3