IM 743-1
7
Installation
The Modbus Communication Module can be factory or field installed. Use the appropriate chiller
selection software program in McQuayTools to include the Modbus Communication Module with
the unit.
For field installation, the Modbus Communication Module kit may be ordered through McQuayTools
or through McQuay Parts. The Modbus Communication Module kit includes the Modbus
Communication Module (RS-485 serial network board) and this installation manual. The Modbus
Communication Module from McQuay Parts is also sold separately (i.e. just the module itself). See
Replaceable Parts List for part numbers.
Mounting
!
CAUTION
Electrostatic discharge hazard.
Can cause equipment damage.
This equipment contains sensitive electronic components that may be damaged by electrostatic
discharge from your hands. Before you handle the Modbus Communication Module, touch a grounded
object, such as the metal enclosure, in order to discharge the electrostatic potential in your body.
Mounting a Modbus Communication Module
To mount a Modbus Communication Module:
1.
Remove power from the MicroTech II Chiller Unit Controller.
2.
Locate the Serial Card slot on the MicroTech II Chiller Unit Controller (see Figure 3.)
3.
Remove the cover from the Serial Card slot if it hasn’t already been removed. Use a small
screwdriver to pry the cover off from one end.
4.
Remove the plastic knockout in the cover.
5.
Figure 4 shows the Serial Card slot that details how the 8-pin plug mates to the 8-pin header on
the Modbus Communication Module.
6.
Grasp the Modbus Communication Module, with the network connector on the underside. The 8-
pin header on the Modbus Communication Module 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 Modbus Communication
Module into the mating guide on the header.
Note:
Since it is impossible to see the connectors mate, this operation relies more on feeling
the Modbus Communication Module into the connector than seeing the connectors
mate.
7.
Insert the Modbus Communication Module, pointing up, into the slot, rolling it into a level
position as you move it into the slot.
8.
Keeping the Modbus Communication Module
level
, move it into 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 Modbus Communication Module 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 Modbus Communication Module to the network.
