Bryant 580J Installation, Start-Up And Service Instructions Manual page 19

The 2-Speed Indoor Fan control circuit inputs to the VFD are
24-VDC signals.
• For ACS320 VFDs the voltage is sourced from the VFD at its
terminal 9 (+24 V). 2-Speed Indoor Fan Motor speed inputs are
received at terminals 13 (DI-2) for low speed (40 Hz) motor op-
eration and 14 (DI-3) for high speed (60 Hz) motor operation.
See Table 11 and Fig. 29 (on page 20).
• For ACH550/580 VFDs the voltage is sourced from the VFD
at its terminal 10 (+24 V). 2-Speed Indoor Fan Motor speed
inputs are received at terminals 14 (DI-2) for low speed
(40 Hz) motor operation and 15 (DI-3) for high speed (60 Hz)
motor operation. See Table 12 and Fig. 30 (on page 20).
When neither input is present, the VFD will shut the fan motor
off. There is no separate indoor fan contactor required in this
application.
J2
6
J1
1
2
3
4
5
J2
6
J1
1
2
3
4
5
24vdc
K1 K2
K2
K1
C
W1
Y2
HUMID
G
24vdc
K1 K2
K2
K1
C
W1
Y2
HUMID
G
Fig. 28 — Connection Schematic - Fan Speed Relay Board and VFD
The VFD used in the 2-Speed Indoor Fan Motor system has
soft start capabilities to slowly ramp up the speeds, eliminating
any high inrush of air volume during speed changes. It also has
internal over current protection for the fan motor.
INDOOR FAN MOTOR
The indoor fan motors used with the VFD are specially manufac-
tured for use with VFD power circuits. The motor winding insula-
tion is specially formulated to resist breakdown due to voltage
stress issues. The motor shaft includes grounding rings to prevent
damage to bearings caused by grounding currents. Replace these
motors with Factory Authorized Parts available from Replace-
ment Components Division (RCD).
9
N/A
K3 K4 JMP2
Lo Spd
K3
Hi Spd
COM
JMP1
K1
K2
K3
K4
ACH550/ACH580 VFD TERMINAL
10
N/A
K3 K4 JMP2
Lo Spd
K3
Hi Spd
COM
JMP1
K1
K2
K3
K4
19
ACS320 VFD TERMINAL
10 11 12 13 14 15
J2
1
YEL
2
WHT
3
4 & 5
11 12 13 14 15 16
J2
1
YEL
2
WHT
3
4 & 5