Carrier 48GC04 - Page 5

5
Units with Electro-mechanical controls
The Fan Speed set up controls are located on the lower section
of the Unit Control Board (UCB). See Fig. 7 for location on 3
phase voltage units or Fig. 8 for location on single phase volt-
age units.
1. Check the job specifications for the CFM (cubic feet per
minute) and ESP (external static pressure) required.
2. Using the chart on the Fan Speed Set Up labels (see
Fig. 9), calculate the Vdc from the CFM and ESP for the
base.
3. If installing any accessories listed at the bottom of the Set
Up Label, add accessory Vdc to base unit Vdc in upper
portion of label.
NOTE: The Fan Speed Set Up labels are located on the High Volt-
age cover in the Control Box.
4. Connect a multimeter to the Vdc terminals on the UCB.
5. Set the Range Switch to either A, B, or C per the Switch
Range table.
6. Using a straight blade screwdriver turn the Vdc control
dial to fine tune the Vdc reading.
7. Record the reading in the Field Setting field.
Fig. 7 — UCB Fan Speed Controls - 3-Phase Units
Fig. 8 — UCB Fan Speed Controls - Single Phase
Units
FAN SPEED SET UP CONTROLS
FAN SPEED SET UP CONTROLS