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RT-SVX22M-EN

Pre-Start

Use the checklist provided below in conjunction with the

“General Unit Requirements” checklist to ensure that the

unit is properly installed and ready for operation.

•

Check all electrical connections for tightness and

“point of termination” accuracy.

•

Verify that the condenser airflow will be unobstructed.

•

Verify that the condenser fan and indoor blower turn

freely without rubbing and are properly tightened on
the shafts.

•

Check the supply fan belts for proper tension and the
fan bearings for sufficient lubrication. If the belts
require adjustment, or if the bearings need lubricating,
refer to the maintenance section of this manual for
instructions.

•

Verify that a condensate trap is installed and the piping

is properly sized and pitched.

•

Verify that the correct size and number of filters are in

place.

•

Inspect the interior of the unit for tools and debris and
install all panels in preparation for starting the unit.

Voltage Imbalance

Three phase 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.

Excessive three phase voltage imbalance between phases
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:

V1, V2, V3 = 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:

The 2.2% imbalance in this example exceeds the

maximum allowable imbalance of 2.0%. This much
imbalance between phases can equal as much as a 20%
current imbalance with a resulting increase in motor
winding temperatures that will decrease motor life. If the
voltage imbalance is over 2%, notify the proper agencies
to correct the voltage problem before operating this
equipment.

Electrical Phasing (Three Phase
Motors)

The compressor motor(s) and the supply fan motor are

internally connected for the proper rotation when the
incoming power supply is phased as A, B, C.

Proper electrical supply phasing can be quickly
determined and corrected before starting the unit by using
an instrument such as an Associated Research Model 45
Phase Sequence Indicator and following the steps below:

•

Turn the field supplied disconnect switch that provides

power to the main power terminal block or to the

WARNING

Hazardous Voltage w/Capacitors!

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.

For additional information regarding the safe discharge
of capacitors, see PROD-SVB06A-EN

% Voltage Imbalance=

100 x AV - VD

where;

AV (Average Voltage)=

Volt 1 + Volt 2 + Volt 3

221 + 230 + 227

= 226 Avg.

100 x 226 - 227

= 2.2%

226

WARNING