Carrier 48FK Read Stop Write Reset, Speed Ctrl, Ð Differential Pressure Switch for Inlet Guide

	CAPACITOR
NULL
ADJUSTMENT	COM
	N.C.
	N.O.

ADJUST VFD SET POINT Ð To adjust the VFD set point, the VFD must be powered; however, since it is located near the supply fan and motor, operation of the fan and motor is not desirable. Either disable the Supply Fan or install the accessory VFD remote display accessory.

DISABLE SUPPLY FAN MOTOR Ð To disable the supply fan motor and change programming of VFD set point:

1. Turn off Indoor Fan Circuit Breaker (IFCB). This will

remove power to the VFD.

SET

POINT

ADJUSTMENT

SET

POINT

INDICATOR

LEGEND

COM Ð Common

N.C. Ð Normally Closed

N.O. Ð Normally Open

NULL DECREASE

SET POINT DECREASE

PLANE

2.	Wait for the VFD display to go blank and remove VFD
	cover without touching any interior components.
3.	Ensure that the charge indicator lamp is out which in-
	dicates that the VFD is discharged. The lamp is located
	on the upper right hand corner of the terminal block. If
	still lit, wait until lamp goes completely out. This may
	take several minutes.
4.	Remove jumper from terminals ST-CC (see Fig. 41) and
	replace VFD cover.
5.	Turn on IFCB.
6.	The drive output will now be disabled but the program-
	ming can be changed.

Fig. 39 Ð Differential Pressure Switch for Inlet Guide

Vane and Static Pressure Control Option and

Modulating Power Exhaust Option

HZ

PERCENT

SECONDS

KW/AMPS/VOLTS

SETUP

PROGRAM RUN

MONITOR

READ STOP

WRITE RESET

LOCAL/REMOTEMANUAL/AUTO

SPEED CTRL RUN MODE

Fig. 40 Ð Variable Frequency Drive Keypad

DETERMINE VFD SET POINT Ð The unit of measure for the Duct Pressure set point at the VFD is output frequency (Hz), representing the desired DP set point (DPSP) in inches of water gage (in. wg). To convert desired DPSP into the VFD set point, refer to Table 13. Locate the pressure value in the table closest to the desired DPSP for this installation and use the corresponding VFD set point (Hz) value. If nec- essary, interpolation between duct static pressure values is permissible.

7.	Change VFD set point according to Table 14 shown
	below.
8.	Once the program changes are completed, turn off IFCB.
9.	Wait for the VFD display to go blank and remove VFD
	cover without touching any interior components.
10.	Ensure that the charge indicator lamp is out which in-
	dicates that the VFD is discharged. The lamp is located
	on the upper right hand corner of the terminal block. If
	still lit, wait until lamp goes completely out. This may
	take several minutes.
11. Replace jumper to terminals ST-CC.
12.	Replace VFD cover.
13.	Turn on IFCB to enable the drive.

For additional information on the VFD (including basic troubleshooting, factory jumper arrangements, and Carrier factory defaults programming), refer to Troubleshooting, Vari- able Frequency Drive section (page 52).

IMPORTANT: The Carrier factory default values for the VFD may be different than the default values of the manufacturer. Refer to the Service section when checking default values.

P24 RES RR F	R S1	S2 S3	S4 RCH P24 LOW LOW
ST FM AM CC	CC	RX PP IV	FP FLC FLB FLA

REMOVE

JUMPER

Fig. 41 Ð Jumper Removal to Disable Motor

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