Carrier 48/50PD05 manual Evaporator Fan Belt Tension Adjustment, Condenser-FanAdjustment

7.Realign fan and motor pulleys:

a.Loosen fan pulley setscrews.

b.Slide fan pulley along fan shaft.

c.Make angular alignment by loosening motor from mounting plate.

8.Tighten belts.

9.Restore power to unit.

C06041

Fig. 31 - Evaporator-Fan Alignment and Adjustment

Evaporator Fan Belt Tension Adjustment

To adjust belt tension:

1.Turn off unit power.

2.Slide out fan deck to service position as shown in Evaporator Fan Service and Replacement section above.

3.Loosen motor mounting plate bolts.

4.Move motor mounting plate to adjust to proper belt tension. Motor adjuster bolts may be used to tighten belts. (See Fig. 30.) Do not overtighten belt.

5.Check for proper belt alignment. Adjust if necessary.

6.Tighten motor mounting plate bolts to lock motor in proper position.

7.Return fan deck back into operating position.

8.Restore power to unit.

Variable Frequency Drive (VFD) Replacement

The 48/50PD units are equipped with a VFD that is mounted behind the blower housing on the fan sled. The VFD’s remote display is mounted on the front of the fan housing for easier access. The VFD is mounted to a plate which is mounted to the fan sled. When accessing the VFD or to remove the VFD, follow the Evaporator fan service and replacement Steps 1-5 and the following steps:

IMPORTANT: If fan deck stop screws are removed for further access, the front of the fan deck MUST BE SUPPORTED.

1.Remove the 2 screws holding the VFD’s mount bracket to the fan sled. The horizontal cross section of the bottom half of the mount bracket is shown on Fig. 32.

2.Cut the wire ties holding the VFD power wires to the fan housing and the two wire ties holding the control wires to the VFD display/keypad at the top of the fan scroll.

3.With the VFD still attached, remove the mount bracket from the fan sled. To do this requires a slight lift on the screw side then a push towards the pulley side of the fan sled.

(See Fig. 32.) Lift out the bracket when the pulley side is clear from the fan sled.

4.With all the wires stilled attached to the VFD, turn the VFD assembly so it is parallel with the fan sled.

5.Pull the VFD assembly to the front of the fan sled and place in a secure flat surface.

6.Disconnect the power, ground, RJ45, and control wiring to the VFD making sure to note their connections.

IMPORTANT: Wires are marked with VFD terminal labels and wiring diagram shows the wiring connections.

7.	Remove the 4 screws holding the VFD to the mount bracket
	and remove the VFD.
8.	Remove the replacement VFD cover and install jumper
	wires provided with it as shown on the unit wiring diagram.
	If jumpers are not provided with the replacement VFD,
	remove them from the defective one or field supply the
	jumpers.
9.	Set AI1 and AI2 DIP switches to the U (off) direction as	48/50PD
	indicated on the plastic housing near the DIP switch.
10.	Replace the VFD with the new one.
11.	Install the 4 screws in the VFD to secure it to the mounting
	bracket.
12.	Connect the wiring as it was on the previous VFD, refer to
	the wiring diagram.
13.	Move the VFD assembly to the back of the fan sled.
14.	Turn the VFD assembly lengthwise with the fan housing,
	making sure the screw side of the bracket lines up with the
	screw holes on the fan sled.
15.	Make sure the bracket s pulley side U bend is clear of the
	fan sled and pull the assembly towards the screw side.
16.	Install the 2 screws in the bracket to secure it to the fan sled.
17.	Secure power and control wires with new wire ties.
18.	Follow the Evaporator fan service and replacement Steps
	6-9.
19.	Power up VFD and set up its parameters per Table 40 in
	Appendix B.

IMPORTANT: If fan deck stops were removed, they must be reinstalled.

For VFD service and maintenance, refer to Appendix B.

C08662

Fig. 32 - VFD Mount Bracket Cross Section

Condenser-Fan Adjustment

1.Shut off unit power supply.

2.Remove condenser-fan assembly (grille, motor, motor cover, and fan) and loosen fan hub setscrews.

3.Adjust fan height as shown in Fig. 33.

4.Tighten setscrews and replace condenser-fan assembly.

5.Turn on power to unit.

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