Replacing An Existing Modbus Communication Module - McQuay MicroTech III Installation And Maintenance Manual

8. The unit controller automatically resets itself approximately 30 seconds after it is powered up.
Note:

Replacing an Existing Modbus Communication Module

Follow these steps to remove an existing Modbus Communication Module from the unit controller
and replace it with a new Modbus Communication Module.
Electric shock hazard. Can cause personal injury or equipment damage.
This equipment must be properly grounded. Only personnel knowledgeable in the operation of the
equipment being controlled must perform connections and service to the MicroTech III Chiller Unit
Controller.
1. Remove power from the unit controller.
2. Locate the Modbus Communication Module to the left of unit controller (see Figure 1).
3. Pull the network cable connector from the Modbus Communication Module.
4. Grasp the Modbus Communication Module and carefully pull it from unit controller (or from an
5. Install the new Modbus Communication Module (see steps 2-5 from previous section).
6. Insert the network cable connector into the Modbus Communication Module (see Figure 2 for
7. Power up the unit controller.
9. The unit controller automatically resets itself approximately 30 seconds after it is powered up.
10
This reset is necessary so that the Modbus Communication Module is synchronized with the unit
controller.
There is a limit of three devices that can be attached to the left side of the unit controller.
adjacent module, if it is attached to one).
location of network connection port).
This reset is necessary so that the Modbus Communication Module is synchronized with the unit
controller.
WARNING
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IM 969