Unit installation

IM 736-4 9
6. Figure 5 details the Serial Card slot with the 8-pin plug that mates to the receptacle on the RS 232
Serial Interface Card. Grasp the RS 232 Serial Interface Card, with the network connector on the
underside. The 8-pin receptacle must mate to the 8-pin plug in the MicroTech II Chiller Unit
Controller. The plug has a guide on each end to direct the card into the mating guide on the
receptacle.
Note: This operation relies more on feeling the RS 232 Serial Interface Card into the connector
than seeing the connectors mate.
7. Insert the RS 232 Serial Interface Card, pointing up, into the slot, rolling it into a level position as
you move it into the slot.
8. Keeping the RS 232 Serial Interface Card level, move it in the slot until you feel the connectors
line up. The correct position seems to be level, toward the left side of the slot, and down slightly
from the top.
9. When you feel the connectors align, press the RS 232 Serial Interface Card into the connector.
Verify that it is firmly seated in the connector.
10. Replace the cover on the Serial Card slot. Slip the cover over the network connector plug.
11. Connect the BACnet Communication Module to the MicroTech II Chiller Unit Controller.
a. Plug the Serial Cable in both the RS 232 Serial Interface Card and the BACnet
Communication Module’s Chiller (RS232) connector.
b. Route the Serial Cable across the hinge and over to the BACnet Communication Module.
12. Connect power to the BACnet Communication Module.
a. Plug the power wires into the BACnet Communication Module’s 24 VAC connector and
neatly route the wires to the unit terminals as indicated in Table , using existing raceways
and/or self-adhesive wire bases whenever possible.
13. Connect the BACnet Communication Module to the network (see Figure 2.)
a. Route the network cable through a knockout to the appropriate connector on the BACnet
Communication Module.
14. Restore power to the MicroTech II Chiller Unit Controller.
Replacing an Existing BACnet Communication Module
To replace a BACnet Communication Module
1. Remove power from the MicroTech II Chiller Unit Controller.
2. Remove the power wires from the terminal block.
3. Locate the Serial Card slot on the MicroTech II Chiller Unit Controller (see Figure 4.)
4. Pull the network cable connector from the BACnet Communication Module.
5. Remove the cover from the Serial Card slot. Use a small screwdriver to pry it off from one end.
6. Grasp the RS 232 Serial Interface Card and carefully pull it from the controller.
7. Install the new RS 232 Serial Interface Card:
a. Grasp the RS 232 Serial Interface Card, with the network connector on the underside. The 8-
pin receptacle must mate to the 8-pin plug in the MicroTech II Chiller Unit Controller. The
plug has a guide on each end to direct the RS 232 Serial Interface Card into the mating guide
on the receptacle. Figure 5 details the Serial Card slot showing how the 8-pin plug mates to
the receptacle on the RS 232 Serial Interface Card.
Note: This operation relies more on feeling the RS 232 Serial Interface Card into the
connector than seeing the connectors mate.
b. Insert the RS 232 Serial Interface Card, pointing up, into the slot, rolling it into a level
position as you move it into the slot.