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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.
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.Check all electrical
connections for tightness and "point
of termination" accuracy.
Verify that the condenser airflow will
be unobstructed.
WARNING
Rotating Components!
Disconnect all electric power,
including remote disconnects before
servicing. Follow proper lockout/
tagout procedures to ensure the
power can not be inadvertently
energized. Failure to disconnect
power before servicing could result
in death or serious injury.
•
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
34
Pre-Start
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:
% Voltage Imbalance =
100 X AV - VD where;
AV
AV (Average Voltage) =
Volt 1 + Volt 2 + Volt 3
3
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:
221 + 230 + 227 = 226 Avg.
3
VD (reading farthest from average) =
221
The percentage of Imbalance equals:
100 X 226 - 221 = 2.2%
226
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 "Line"
side of the optional factory
mounted disconnect switch to
the "Off" position.
•
Connect the phase sequence
indicator leads to the terminal
block or to the "Line" side of the
optional factory mounted
disconnect switch as follows;
Black (phase A) to L1
Red (phase B) to L2
Yellow (phase C) to L3
•
Close the field supplied main
power disconnect switch or
circuit protector switch that
provides the supply power to the
unit.
RT-SVX21F-EN
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