86
Enertech Global
IOM, ZS/ZT Models
SECTION 12: TROUBLESHOOTING
When any compressor bearing unit is connected
to a weak power supply, starting current will
generate a significant “sag” in the voltage
which reduces the starting torque of the
compressor motor and increases the start time.
This will influence 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 Electrial Data