Form O-Y, PN 273647R5, Page 8
3.2 Supply Fan
and Variable
Frequency Drive
Fan motors are permanently lubricated; lubrication is not required, During
maintenance, remove any accumulation of dirt and grease
. The fan CFM was
checked and balanced at startup. To recheck, follow the instructions in the installation
manual, Form I-Y, Paragraph 10.3.
If service is required, the supply fan is mounted on a sled that will slide out of the
cabinet.
Instructions for sliding out the supply fan:
1. Turn off the power and lock the disconnect switch.
2. Open the supply fan door and the cooling cabinet door.
3.
The flexible duct joining the supply fan to the cooling compartment is visible.
Locate the metal flange holding the duct to the cabinet. Remove the two screws
from fan sled (locations shown in picture on the left) and the flange to free the duct
so that it can be slid out with the fan.
4. Open the electrical box on the fan. Mark and disconnect the wires.
5.
Carefully slide the complete fan sled out of the cabinet.
6. When service is complete, slide the sled into the cabinet. Re-connect the wires
and re-attach the flange to hold the flexible duct in place. If the pressure tube was
removed during service, be sure to re-attach it securely. Reinstall two screws into
the fan sled.
Variable Frequency
Drive
Approx fan sled
screw locations
Function:
When the main controller calls for supply fan operation, a variable fre-
quency drive (VFD) responds to operate the motor.
The VFD is located on the high voltage electrical panel (See
FIGURE
1, page 4).
Control of the variable frequency drive module is dictated by the main controller, and
depending on what was ordered, can function in response to temperature, CO
2
, or
pressure controls. !
Service: Remove any dirt or dust. Check the wire connections.
If a VFD needs
to be replaced, use a factory-authorized replacement designed for the application.
Supply fan in "slide
out" position
Code
Control Panel Display
1
LCD display -
Divided into 5
areas
Upper left - Control location
Upper right - unit of the displayed value
Center - Parameters and signal values, menus and alarm codes
Lower left and center - Operation state
Lower right - Motor rotation
2
RESET / EXIT
Resets faults and exits to higher menus
3
MENU / ENTER Menu selection and saves value
4
UP
Scrolls up through menu / list
Increases value of parameters or reference values
5
DOWN
Scrolls down through menu / list
Decreases value of parameters or reference values
6
LOC / REM - VFD controlled by main controller
7
DIR - Changes the direction of the motor
8
STOP - Stops the drive
9
START - Starts the drive
9) START
7) DIR
3) MENU / ENTER
5) DOWN
4) UP
8) STOP
6) LOC / REM
2) RESET / EXIT
1) LCD Display
Variable Frequency
Drive Model ACS355
Variable Frequency
Drive Model ACS550
FIGURE 4 - VFD
Display
3.0 Maintenance and Service Procedures - Unit & Cooling Components (cont'd)
