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www.DaikinApplied.com 21
IM 777-8 • Skyline Air Handler
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Wiring
DANGER
Capacitor hazardous voltage! Failure to disconnect power
and discharge capacitors before servicing will result in
serious injury or death. Disconnect all electric power
(including remote disconnects) before servicing. Perform
lockout/tag out procedures to ensure that power can
not be energized. For variable frequency drives,or other
energy storing components that have been furnished and
mounted by either Daikin, or by others, refer to the specific
manufacturer’s literature for allowable waiting periods
for discharge of capacitors. Verify capacitors have been
discharged using an appropriate voltmeter.
CAUTION
Use copper conductor only .
Failure to use copper
conductors can result equipment damage.
CAUTION
The base section of each cabinet has a drip pan installed
below every panel that drains to the outside frame trough. Any
holes cut through the bottom of the unit must also penetrate
the drip pan. If holes are cut in the drip pan, seal them to
prevent moisture leakage.
Figure 36: Electrical Conduit Location
• Electrical service to each fan must correspond to the rated
voltage on the motor or electrical panel nameplate and
conform to the National Electric Code and local restrictions.
• Connect each fan section metal frame to the building
electrical ground.
• A door electrical interlock is not provided as standard.
• Thermal motor protection is external to the unit. Locate
electrical conduit entrances for units above the bottom
of the unit, high enough to clear components inside, but
below the bottom of the fan motor junction box (
Figure 36
).
• When the unit is provided with an external junction box
and variable frequency drive (VFD), the VFD itself will
be mounted on the drive side fan panel inside the fan
cabinet. The external junction box will provide loose wire
connection to the VFD and to the motor. An external
mounted keypad/display control box will be provided and
connected to the VFD for manual adjustment of the VFD.
• When not being serviced, close and secure electrical panel
doors to prevent accidental contact with live parts and
prevent ingress of moisture and airborne contaminants.
• For instances where multiple motors are being driven
by a single VFD, be sure to set up the VFD and size the
wiring according to the power requirements of all motors
that are being driven by that VFD.
• Control wiring—access to the VFD is through the fan
cabinet access door for single fans. Provide shielded
cable only as described in the VFD manual provided with
the unit. Route wire through panel so that it not interfere
with any other components or in the way of any access
doors. Do not drill through drip or drain pans. Refer to the
VFD installation manual provided with the unit for detailed
control wiring instructions.
• For multiple fans in parallel, the VFD(s) are mounted
inside of the electrical enclosure, which is mounted
on the exterior of the fan section. When multiple fan
sections are provided with multiple VFDs, they must be
set up so that the fans always start simultaneously and
are set to ramp up and down together. Do not attempt to
run fans in parallel at different speeds as this can result
in uneven airflow that can cause performance, sound,
and vibration problems that can lead to failure. Provided
that the fan is capable of running fast enough and the
motor is sized appropriately, VFDs may be operated
up to a maximum recommended frequency of 90 Hertz
for 1800 RPM and slower motors. Motors that are 3600
RPM may be operated up to a maximum speed of 4000
RPM or 66.7 Hertz provided the fan is rated that high.
Operation above 4000 RPM can damage motor bearings
and is not recommended.
