13.2.3 Belt Installation And Tensioning; Figure 99 Auto-Belt Tensioning Motor Base - Emerson Liebert DS Series User Manual

13.2.3 Belt Installation and Tensioning

1. Select the appropriate replacement of belts (matched set) and position on drive package.
To maximize performance and reliability of Liebert DS equipment, use only Liebert belts. Contact
your local Emerson representative for replacement belts.
2. Ensure pulley grooves are properly aligned. If adjustment is required, loosen (do not remove) four
nuts in adjustment slots (see Figure 99) holding motor base to unit frame and slide motor base
assembly into alignment.
3. Tension belts by turning adjustment nut clockwise (right) until motor base carriage stops
moving downward.
4. Ensure minimum 1/2" (12.7mm) clearance exists from motor base carriage to base front flange
(see Figure 99). If the clearance is less than 1/2" (12.7mm), select shorter belts.
5. Mark the adjustment nut and rotate clockwise (right) five additional full turns. This sets internal
spring for proper belt tension, no readjustments necessary.

Figure 99 Auto-belt tensioning motor base

Minimum 1/2"
(13mm) Gap
Blower Bearing Maintenance
• Field lubrication is NOT required for the life of the bearing.
• Bearings are permanently sealed and self-lubricating and cannot be greased.
Blower Bearing Inspection
1. Disconnect power to unit.
2. Remove drive belts (see 13.2.2 - Belt Removal).
3. Inspect bearing for tightness of set screws and mounting bolts.
4. Rotate fan wheel by hand.
5. Listen for unusual noise and look for signs of unusual play.
Blower Bearing Replacement
1. To maximize performance and reliability of Liebert DS equipment, use only SealMaster Reduced
Maintenance pillow block bearing with tapered lands race and double lock set screws. Contact
local Emerson representative to order replacement bearings.
2. Properly mount and align bearings on shaft. Tighten set-screws in proper sequence and to proper
torque using a torque wrench in accordance with the manufacturer's instructions.
Motor Plate
Adjustment Slot
Adjustment Nut
134
Maintenance
Spring
Housing
Motor Base
Carriage
DPN000995
Rev. 0