Carrier 48/50PD05 manual Variable Frequency Drive VFD

Variable Frequency Drive (VFD)

The VFD varies the frequency of the AC voltage supplied to the indoor fan. (See Fig. 20 and Table 23.) This causes the variance in the speed of the fan. The commanded fan speed is received by the VFD from the AUX1 board as a 2-10vdc signal.

The AI1 DIP switch must be in the off (or towards “U”) position to properly read the analog signal. There are three jumper wires that must remain installed for proper operation. The VFD is mounted behind the fan housing on the fan sled and the remote keypad is mounted on the front of the fan housing for easy access. The VFD is factory set to the auto mode for unit operation.

48/50PD

				C09146
		Fig. 20 - Variable Frequency Drive (VFD)
	Table 23 — VFD Connections
DISPLAY NAME	POINT DESCRIPTION	TYPE OF I/O	TERMINAL	TERMINAL
			NUMBER	NAME
	LOW VOLTAGE INPUTS
	Shielded Cable Ground	Shield	1	SCR
F.SPD	Commanded Fan Speed	2---10vdc	2	AI1*
	Analog Input 1 Common	Ground	3	AGND
	Low Voltage Power (jumped to DI1 & DI4)	24v	10	24v
	Low Voltage Common (jumped to DCOM)	Ground	11	GND
	Discrete Inputs Common (jumped from GND)	Ground	12	DCOM
	Discrete Input 1 (jumped from 24v)	Switch Input	13	DI1
	Discrete Input 4 (jumped from 24v)	Switch Input	16	DI4
	HIGH VOLTAGE
	Voltage Leg from IFC---21	Voltage Input	U1	MAINS
	Voltage Leg from IFC---22	Voltage Input	V1	MAINS
	Voltage Leg from IFC---23	Voltage Input	W1	MAINS
	Voltage Leg to IFM---3	Voltage Output	U2	MOTOR
	Voltage Leg to IFM---2	Voltage Output	V2	MOTOR
	Voltage Leg to IFM---1	Voltage Output	W2	MOTOR

* Requires the Al1 dip switch to be in in the Off (or towards “U”) position.

53