Filter
Top Products
Maintenance
112
12.1.1 Filter 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.
12.1.2 Filter 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
12.2 Blower Drive System
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.
Do Not Use
Long Pleat Construction
DPN000994
Rev. 0
16"
(406mm)
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.