Trane SCXG-SVX01B-EN manual Supply Fan, maintenance, Maintenance procedures, Fan Drive

maintenance

Maintenance procedures

Variable Frequency Drive (VFD)

The VFD access panel is hinged to allow service access to the fan motor and belt drive components that are located behind it.To swing the panel open:

•Remove the unit center cover panel to the left of the VFD panel.

•Remove and discard the sheet metal shipping screws along the top and bottom edges of the VFD panel.

•Disconnect the communications cable

from the keypad on the VFD door panel.

•Turn the two slotted-head fasteners on the right edge of the VFD panel fully counterclockwise.

•Pull on the handle to swing the panel 180°.

To close and reattach the panel, reverse the procedures listed above.

Note: To secure the panel in the open position during service procedures, attach the chain mounted to the cabinet frame behind the unit center cover panel to the chain retainer notch on the edge of the VFD panel.

Note: Verify that all wires are in their proper position and not rubbing before replacing the panel.

Note: Panel weight rating = 225 lbs. total, including factory-installed components.

Supply Fan

Fan Drive

Perform the following procedures according to the “Periodic Maintenance Check List”.

￿WARNING

Hazardous Voltage w/Capaci- tors!

literature for allowable waiting periods for discharge of capacitors.Verify with an appropriate voltmeter that all capacitors have discharged. Failure to disconnect power and discharge capacitors before servicing could result in death or serious injury.

Note: For additional information regard- ing the safe discharge of capacitors, see PROD-SVB06A-EN or PROD-SVB06A-FR.

1.Rotate the fan wheel to ensure it turns freely in the proper direction and is not rubbing on the fan housing, inlet, or inlet guide vanes. If necessary, center the fan wheel again.

2.Check the position of both shafts. Fan and motor shafts should operate parallel to each other for maximum belt and bearing life. Shim as necessary under the motor or fan bearings to obtain proper alignment.

3.Check the fan motor sheave alignment with straight edge or a tightly pulled string. For sheaves of different widths, place a string in the center groove of

each sheave and pull it tight for a center line. See Figure M-MP-6 for recommended torques.

4.Once the sheaves are properly aligned, tighten sheave set screws to proper torque. SeeTables M-MP-1 and M-MP-2 for recommended torques.

5.Check belt tension. Refer to the “Measuring BeltTension” section.

6.If required, adjust belt to the minimum recommended tension. Refer to “Adjusting BeltTension” section.

7.Retighten bearing set screws to the proper torques after aligning the sheaves. SeeTables M-MP-1 and M- MP-2 for proper torques.

8.Check the fan bearing locking collars for tightness on the shaft.To tighten the locking collar, loosen the set screw and slide the collar into its proper position over the extended end of the inner case.Tighten the set screw to the torque value inTables M-MP-1 and M- MP-2.

9.During air balancing, verify the sheave alignment, belt tension, and that the shaft is parallel.

Disconnect all electric power, including remote disconnects before servicing. Follow proper lockout/tagout proce- dures to ensure the power cannot be inadvertently energized. For variable frequency drives or other energy storing components provided byTrane or others, refer to the appropriate manufacturer’s

Figure M-MP-4. Fan shaft and motor sheave alignment

94 SCXG-SVX01B-EN