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Installation Electrical
Water Pump Power Supply
Provide power supply wiring with fused disconnect for
both the chilled water and condenser water pumps.
Compressor Motor Phase Sequencing
Always verify that proper rotation of the compressor is
established before the machine is started. Proper motor
rotation requires confirmation of the electrical phase
sequence of the power supply. The motor is internally
connected for clockwise rotation with incoming power
supply phased A, B, C.
Units with Optional AFD.
NOTICE
Equipment Damage!
Changing default clockwise phase rotation or enabling
phase reversal protection could prevent proper chiller
operation or cause equipment damage.
•
Do NOT change Adaptive Frequency™ drive (AFD)
phase rotation to counterclockwise.
•
Do NOT enable phase reversal protection.
AFD must be set with phase rotation clockwise (default
from factory), and phase reversal protection DISABLED.
All Units.
To confirm the correct phase sequence (ABC),
use a Model 45 Associated Research Phase indicator or
equivalent.
Voltages generated in each phase of a polyphase
alternator or circuit are called phase voltages. In a three-
phase circuit, three sine wave voltages are generated,
differing in phase by 120 electrical degrees. The order in
which the three voltages of a three-phase system succeed
one another is called phase sequence or phase rotation.
This is determined by the direction of rotation 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).
42
3. Connect the phase sequence indicator leads to the line
power terminal block (or the unit mounted disconnect)
as follows:
Phase Seq. Lead
Black (Phase A)
Red (Phase B)
Yellow (Phase C)
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 w/Capacitors!
Failure to disconnect power and discharge capacitors
before servicing could result in death or serious injury.
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. For variable frequency drives
or other energy storing components provided by Trane
or others, refer to the appropriate manufacturer's
literature for allowable waiting periods for discharge of
capacitors. Verify with a CAT III or IV voltmeter rated
per NFPA 70E that all capacitors have discharged.
6. If "CBA" indicator glows instead, open unit main
power disconnect and switch two line leads on the line
power terminal block (or the unit mounted
disconnect). Re-close main power disconnect and
recheck phasing.
7. Reopen the unit disconnect and disconnect the phase
indicator.
Electrical Connections
Proper starter/control panel line-side lug sizes are
specified on the unit submittals. These lug sizes must be
compatible with conductor sizes specified by the electrical
engineer or contractor.
For recommended field connection lug sizes (RTHD
starters) see unit submittal.
Circuit Breakers and Non-Fused Disconnect
Switches
(Factory Installed Option)
Units that are ordered with factory installed circuit
breakers or non-fused disconnect switches ship with the
handle in the control panel. The handle must be installed
prior to starting the unit.
The operating mechanism is already pre-installed on the
Disconnect/ Circuit Breaker frame.
The hole locations and shafts lengths have already been
cut, and the shaft already installed.
1TB1 Terminal
L1
L2
L3
RTHD-SVX01K-EN
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