Enertech VS Series - Unit Electrical Data

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Enertech Global IOM, VS/VT Models, Rev A
Section 12: Troubleshooting
When any compressor bearing unit is connected to
a weak power supply, starting current will generate
a signicant “sag” in the voltage which reduces
the starting torque of the compressor motor and
increases the start time. This will inuence the rest of
the electrical system in the building by lowering the
voltage to the lights. This momentary low voltage
causes “light dimming”. The total electrical system
should be evaluated with an electrician and
HVAC technician. The evaluation should include
all connections, sizes of wires, and size of the
distribution panel between the unit and the utility’s
connection. The transformer connection and sizing
should be evaluated by the electric utility provider.
Note: Proper Power Supply Evaluation
⚠ CAUTION ⚠
CHECK COMPRESSOR AMP DRAW TO VERIFY
COMPRESSOR ROTATION ON THREE PHASE UNITS.
COMPARE AGAINST UNIT ELECTRICAL TABLES.
REVERSE ROTATION RESULTS IN HIGHER SOUND
LEVELS, LOWER AMP DRAW, AND INCREASED
COMPRESSOR WEAR. THE COMPRESSOR INTERNAL
OVERLOAD WILL TRIP AFTER A SHORT PERIOD OF
OPERATION.
⚠ CAUTION ⚠
ALL VOLTAGE CODE “3” 460V UNITS UTILIZE A 277V
ECM MOTOR WHICH REQUIRES A NEUTRAL WIRE.
THE MOTORS ARE WIRED BETWEEN THE NEUTRAL
AND ONE HOT LEG OF THE CIRCUIT. SOURCE
WIRING MUST BE WYE (STAR) CONFIGURATION.
3-PHASE DELTA CONNECTIONS WILL NOT PROVIDE
THE CORRECT WIRING AND WILL CAUSE THE UNIT
NOT TO OPERATE.
Example 1: WYE (STAR) Electrical Circuit Example 2: DELTA Electrical Circuit
E
P
E
L
A
B
C
E
L
E
L
E
P
E
P
NEUTRAL OR
GROUND
E
L
E
L
E
L
E
P
E
P
E
P
I
P
E
P
E
L
A
B
C
E
L
E
L
E
P
E
P
NEUTRAL OR
GROUND
E
L
E
L
E
L
E
P
E
P
E
P
I
P
Unit Electrical Data