Table of Contents
Advertisement
increase in winding temperature that will decrease
compressor motor life.
Equipment Grounding
NOTICE
Use Copper Conductors Only!
Failure to use copper conductors could result in
equipment damage as unit terminals are not designed
to accept other types of conductors.
Provide proper grounding at the connection point
provided in the unit control panel.
Unit Power Wiring
WARNING
Hazardous Voltage!
Failure to disconnect power before servicing could
result in death or serious injury. Disconnect all electric
power, including remote disconnects before servicing.
Follow proper lockout/tagout procedures to ensure the
power can not be inadvertently energized.
The installing contractor must connect appropriate power
wiring (with fused disconnects) to the unit-mounted, non-
fused disconnect in the power section of the unit control
panel. Electrical schematics and component location
drawings are also mounted on the inside of the control
panel door.
The unit power fused disconnect switch should be located
in the general area of the unit, to comply with NEC or local
codes. Some codes require line-of-sight disconnect
locations. The unit mounted non-fused disconnect can be
used as an emergency shutdown device.
Scroll Compressor Electrical Phasing
NOTICE
Compressor Damage!
Operating compressors in reverse rotation will cause
damage or failure of the compressor.
It is critical that proper rotation of the scroll compressors
be established before the machine is started. Proper motor
rotation requires confirmation of the electrical phase
sequence of the power supply. The motor is internally
connected for clockwise rotation with the inlet power
supply phased "ABC" or "L1, L2, L3".
The order in which the three voltage waveforms of a three-
phase system succeed one another is called phase
sequence or phase rotation. When rotation is clockwise,
phase sequence is usually called "ABC" and when
counterclockwise, "CBA".
CG-SVX044B-EN
This direction may be reversed by interchanging any two
of the line wires. The possibility of interchanging the
wiring makes a phase sequence indicator necessary to
quickly determine the proper phase rotation.
Setting the Proper Electrical Phase
Sequence
Proper compressor motor electrical phasing can be quickly
determined and, if necessary, corrected before starting the
unit. Use a quality instrument, such as an Associated
Research Model 45 Phase Sequence indicator or
equivalent and follow this procedure:
1. Verify that all operating controls for the unit are in the
"Off" position.
2. Turn power to CICD unit "Off" using supply power
disconnect to the unit. Verify that power to CICD unit is
"Off" and that there is no voltage on "Line" or entering
side of the CICD panel mounted unit disconnect.
3. Connect the phase sequence indicator leads to the
"Load" or leaving side of the CICD unit panel mounted
disconnect as follows:
Phase Sequence Lead
Black (Phase A)
Red (Phase B)
Yellow (Phase C)
4. Turn power to CICD unit "On" using the supply power
disconnect to the unit
5. Read the phase sequence displayed on the indicator.
The "ABC" LED on the face of the phase indicator will
glow if phase sequence is ABC.
6. If the "CBA" indicator glows instead, turn power to
CICD unit "Off" using the supply power disconnect to
the unit, then verify that the power to the CICD unit is
"Off" and that there is no voltage on the "Line" side of
the CICD panel mounted unit disconnect. Reverse two
wires on the "Line" or entering side of the CICD panel
mounted disconnect switch. Turn power to CICD unit
"On" and recheck phase sequence
7. If phase sequence is correct, turn power to CICD unit
"Off" using the supply power disconnect to the unit.
Verify that power to the CICD unit is "Off" and that
there is no voltage on "Line" or entering side of the
CICD panel mounted unit disconnect. Remove the
phase indicator and restore power to the CICD unit.
Installation Electrical
Terminal ID
L1
L2
L3
(Step 5
above).
31
Advertisement
Table of Contents
