Daikin Destiny VFD Series, Installation And Maintenance Manual

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IM 782-12 • DESTINY AIR HANDLERS 22 www.DaikinApplied.com
Installation
Variable Frequency Drive (VFD)
(Optional)
DANGER
Fire hazard. Failure to use fast-blow J-type fuses could result in property d
mage, injury, or death. Fast-blow fuses must be installed upstream of a VFD.
CAUTION
Never operate a fan over the maximum speed indicated on the fan curve,
as this may cause fan damage and severe unit vibration.
1. When the unit is provided with a VFD only, refer to the
VFD manual for wire size and torque requirements. A
fast-blow fused disconnect is recommended for VFD
applications. Motor operation below 20 Hz or over 90 Hz
is not recommended. For typical wiring diagrams, see
Figure 29 and Figure 30 .
2. Refer to IM 1190 (MD4 drives) or IM 1191 (MD5 drives)
for VFD set-up details. The drives are installed with only
default programming and are to be field configured to
meet application requirements.
3. Units with Direct-Drive Plenum fans need to be
reprogrammed in the field according to design point
parameters. Refer to project documentation and/or fan
curves ( Figure 33 through Figure 41 ) for appropriate fan
speeds associated with the job. Use the formula below
to calculate the maximum frequency associated with the
maximum allowable fan speed.
F
max
= 60 Hz × (W
max
/ W
motor
)
F
max
- maximum frequency allowable for particular
application (Hz)
W
max
- maximum fan speed (rpm); refer to fan curves
W
motor
- nominal motor speed (1800/3600 rpm); refer to
motor nameplate
Refer to Table 34 on page 45 for operating limit information
for Backward-Inclined Direct-Drive Plenum fans.
Starters and Disconnects
(Optional)
1. The fan motor is factory wired to an externally mounted
control box. Control box options include: disconnect-
only (fused and non-fused) and starter-fused disconnect
transformer.
2. A fast-blow fused disconnect (J-type fuses) is used in
VFD applications.
3. A fused control transformer allows the fan to be
sequenced by standard 24-volt thermostat or controller.
4. An indoor panel with tool access hinged door houses
all the components and is generally mounted on the
unit’s bulkhead panel. The panel enclosure has several
knockouts located on the side, top, and bottom.
5. All field wiring must be in conformance with the National
Electric Code and local restrictions.
6. Refer to Figure 27 and Figure 28 for typical disconnect-
only wiring diagrams. Refer to Figure 46 and Figure 47
for typical full control box diagrams.