Engineering Manual

VERTICAL-HORIZONTAL INDOOR UNITS
Installation and Best Layout Practices
Power Wiring / Communications Cable Guidelines
A voltage drop may cause the following problems:
• Magnetic switch vibration, fuse breaks, or disturbance to the normal
function of an overload protection device.
• Compressor will not receive the proper starting current.
• Loose wiring may cause unit malfunction, or the terminal to
overheat and catch fire.
• Terminal screws may become loose during transport. Properly
tighten the terminal connections during installation.
• Follow manufacturer’s circuit diagrams in the technical manuals.
• Confirm power source specifications.
• Confirm that the electrical capacity is sufficient.
• Starting current must be maintained ±10 percent of the rated current marked on the outdoor unit name plate.
• Confirm cable thickness specifications.
• It is recommended that a circuit breaker is installed, especially if conditions could become wet or moist.
• Include a disconnect in the power wiring system, add an air gap contact separation of at least 1/8 inch in each active (phase) conductor.
Access Holes
for Wiring
Control
Box Cover
Top Front
Panel
Connection Cable
Communications Cable
Nut
Conduit
Mounting Plate
1/2-inch Conduit
Connecting the Power Wiring and Communications Cable
1. To access the terminal block, first unscrew the top front panel,
and then unscrew the cover from the control box.
2. Knockout the access holes for the wiring. Insert the power wiring
/ communications cable from the outdoor unit or branch distribu-
tion unit (Multi F MAX systems only) through the conduits, pass
the conduits through the designated access holes, and then in-
sert the conduits into the control box. To prevent electromagnetic
interference and product malfunction, leave a space between the
power wiring and communications cable outside of the indoor
unit.
3. Connect the power wiring and communications cables to the
appropriate terminals on the indoor unit control board. Verify that
the color and terminal numbers from the outdoor unit or branch
distribution unit (Multi F MAX systems only) wiring match the
color and terminal numbers on the indoor unit.
4. Fill in any gaps around the conduit access holes with sealant to
prevent foreign particles from entering the indoor unit.
Figure 239:Connecting the Power Wiring and Communications Cable.
Indoor Unit Terminal Block
1(L1 )2(L2)
GND
3
Outdoor Unit Terminal Block or
Branch Distribution Unit Terminal Block
(Multi F MAX Systems Only)
GND
GRN /
YLW
BR
BL
RD
3 or S
Figure 240:Indoor Unit to Outdoor Unit / Branch Distribution Unit (Multi F MAX
systems only) Power Wiring / Communications Cable Connections.
VERTICAL-HORIZONTAL | 169
Vertical-Horizontal Air Handling
Due to our policy of continuous product innovation, some specications may change without notication.
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MULTI
F
MAX
MULTI
F