Carrier 50PD05 Operating And Service Instructions page 81

APPENDIX B - VFD INFORMATION
On 48/50PD units, the supply fan speed is controlled by a 3-phase
VFD. The VFD is located in the supply fan section behind an
indoor fan scroll. The VFD speed is controlled directly by the
ComfortLink
TM
controls through a 0-10Vdc signal based on a
space temperature sensor. The VFD has a display, which can be
used for service diagnostics, but setup of the control is to be done
through the scrolling marquee display.
The VFD is powered during normal operation to prevent
condensation from forming on the boards during the off mode and
is stopped by driving the speed to 0 (by sending a 0Vdc signal to
the VFD). The units use ABB VFDs. The interface wiring for the
VFDs is shown in the figure below. The VFD connects to
ComfortLink through a 0-10Vdc output on the AUXI board.
Terminal designations are shown in the Terminal Designation table.
Configurations are shown in the VFD Configurations table.
Table 39 -- VFD TERMINAL DESIGNATIONS
TERMINAL FUNCTION
U1
V1
W1 Three-Phase main circuit input power supply
U2
V2 Three-Phase AC output to motor, 0V to maximum input
W2 voltage level
X1-11 (GND)
Xl - 12 (COMMON) Factory-supplied jumper
Xl - 10 (24VDC)
Xl - 13 (DI- 1) Run (factory-supplied jumper)
Xl -10 (24VDC) Start Enable 1 (factory-supplied jumper). When opened,
Xl -16 (DI-4) the drive goes to emergency stop
X1-2 (AI- 1)
X1-3 (AGND) Factory wired for 0-10Vdc remote input
TERMINAL Xl
O ' Z "_" Z O ....
o0 _ Co _ 04 _ _ E 5
< + CO O
£3
ZS] ZZ
I
m
0-10Vdc signal from Comfort Link
Fig. 40 - VFD Wiring
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81