Multi F Engineering Manual

FOUR-WAY VAHU INDOOR UNITS
Installation and Best Layout Practices
Power Wiring / Communications Cable Guidelines
• 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 required 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 distribution 
unit (Multi F MAX systems only) through the conduits, pass the 
conduits through the designated access holes, and then insert 
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.
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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
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• Loose wiring will cause unit to malfunction, overheat, and catch fire, resulting in severe injury or death.
Note:
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A voltage drop will cause the following problems:
• 0DJQHWLFVZLWFKYLEUDWLRQIXVHEUHDNVRUGLVWXUEDQFHWRWKHQRUPDOIXQFWLRQRIDQRYHUORDGSURWHFWLRQGHYLFH
• Compressor will not receive the proper starting current.
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180 |  VERTICAL-HORIZONTAL
Multi F and Multi F MAX Indoor Unit Engineering Manual
MULTI 
F
MAX
MULTI 
F










