User manual

Maintenance
133 Liebert
®
DS
™
13.1 Filters
NOTICE
Risk of improper filter installation and filter collapse. Can cause equipment damage.
Pleat direction is non-standard. Use only short-pleat filters (see Figure 98). Long-pleat filters
are subject to collapse at high airflows.
To maximize the performance and reliability of Liebert DS equipment, use only Liebert filters.
Contact your local Emerson representative to order replacement filters.
13.1.1 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 98).
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.
13.1.2 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
filter 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 98).
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.
Table 58 Filter quantities
028 035 042 053 070 077 105
Downflow Models
Quantity 3334 4 4 4
Nominal Size, inches
2 @ 25x20
1 @ 25x16
2 @ 25x20
1 @ 25x16
2 @ 25x20
1 @ 25x16
4 @ 25x20 4 @ 25x20 4 @ 25x20
2 @ 25x20
4 @ 25x16
Upflow Models (Front & Rear return) Filters located in separate filter box on rear return, located on lower unit panel
Quantity
444 6 6 6 8
Nominal Size, inches 25x20 25x20 25x20 25x20 25x20 25x20 25x20
Disposable Type - Nominal Sizes and Quantities, Standard MERV 8 or Optional MERV 11; (filter types cannot be mixed, must be all
MERV 8 or all MERV 11)