Voltage Supply And Voltage Imbalance - Trane Voyager Commercial Installation & Operation Manual

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Live Electrical Components!
During installation, testing, servicing and troubleshooting of this product, it may be necessary
to work with live electrical components. Have a qualified licensed electrician or other individual
who has been properly trained in handling live electrical components perform these tasks.
Failure to follow all electrical safety precautions when exposed to live electrical components
could result in death or serious injury.
HIGH VOLTAGE IS PRESENT AT TERMINAL BLOCK HTB1 OR UNIT DISCONNECT SWITCH.
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Voltage Supply and Voltage Imbalance

Supply Voltage
Electrical power to the unit must meet stringent requirements for the unit to operate properly.
Measure each leg (phase-to-phase) of the power supply. Each reading must fall within the
utilization range stamped on the unit nameplate. If any of the readings do not fall within the proper
tolerances, notify the power company to correct this situation before operating the unit.
Voltage Imbalance
Excessive voltage imbalance between phases in a three phase system will cause motors to
overheat and eventually fail. The maximum allowable voltage imbalance is 2%. Measure and
record the voltage between phases 1, 2, and 3 and calculate the amount of imbalance as follows:
% Voltage Imbalance = where;
AV (Average Voltage) =
Volt 1, Volt 2, Volt 3 = Line Voltage Readings
VD = Line Voltage reading that deviates the farthest from the average voltage.
Example:
If the voltage readings of the supply power measured 221, 230, and 227, the average volts would be:
VD (reading farthest from average) = 221
The percentage of Imbalance equals:
RT-SVX34C-EN
Turn the "System" selection switch to the "Off" position and the "Fan" selection switch (if
Applicable) to the "Auto" position.
Close the disconnect switch or circuit protector switch that provides the supply power to the
unit's power terminal block or unit mounted disconnect switch.
WARNING
Observe the ABC and CBA phase indicator lights on the face of the sequencer. The ABC
indicator light will glow if the phase is ABC. If the CBA indicator light glows, open the disconnect
switch or circuit protection switch and reverse any two power wires.
Restore main electrical power and recheck phasing. If the phasing is correct, open the
disconnect switch or circuit protection switch and remove the phase sequence indicator.
( AV VD )
–
× 100
--------------------------- -
AV
Volt1 Volt2 Volt3
+ +
---------------------------------------------------------------
3
221 230 227
+ +
---------------------------------------------- - 226Avg
=
3
226 221
–
× 100 2.2percent
----------------------------
=
226
Startup
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