Liebert DS Blower Drive System, Filter Replacement Procedure-Downflow Units, Do Not Use

Maintenance

12.1.1Filter Replacement Procedure—Downflow Units

1.Disconnect power from the Liebert DS.

2.Using a stepladder, remove filters from the top of the unit.

The optional downflow return air plenum includes a filter access door.

3.Replace with new filters—install the filters in the proper direction of the airflow (see Figure 82).

4.Test the operation of the filter clog switch.

The unit panels must be in place and closed to find this point.

5.Start the blower and turn the switch counterclockwise until the alarm is energized.

6.Turn the adjusting knob one turn clockwise or to the desired filter change point.

12.1.2Filter Replacement Procedure—Upflow Units

1.Disconnect power from the Liebert DS.

2.Remove the lower front access panel and remove the filters.

For upflow front return units, remove the lower front access panels, lift filters to the top of the fil- ter rack and tilt forward for removal.

For upflow rear return units, remove filters using filter access door in rear return filter box.

3.Replace with new filters—install the filters in the proper direction of the airflow (see Figure 82).

4.Test the operation of the filter clog switch.

The unit panels must be in place and closed to find this point.

5.Start the blower and turn the switch counterclockwise until the alarm is energized.

6.Turn the adjusting knob one turn clockwise or to the desired filter change point.

Figure 82 Proper filter pleat direction

16"

(406mm)

Do Not Use

25"

(635mm)

Short Pleat Construction

The filter pleat direction should run parallel to the direction of the short side of the filter , as shown above. Do NOT use long pleat filter construction , as shown at right above, because it can result in filter collapse .

12.2Blower Drive System

Long Pleat Construction

DPN000994

Rev. 0

Blower drive system components that are part of the maintenance schedule include the blower wheel(s) drive shaft, bearings, pulley, belts, sheave, motor auto-tension base and motor. See Blower Section on page 122.

! WARNING

Risk of crushing and pinching action from spring-loaded motor base. Can cause serious injury to hands and fingers.

Improper drive belt removal may cause the motor base to slam down suddenly. Read the directions in this manual and on the unit instruction labels before servicing the belts, motors or pulleys. Follow all directions when servicing the unit.

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