Application Note: Controlling a Trane RTHC / RTWA Chiller with Minimal IO Points

Solution:

Using a 75F Edge 10 (or a JACE in the case of a full central plant), a Trane RTHC/RTWA Series Chiller can be controlled in the form of two IO points.  The Edge 10 will come pre-programmed for a true plug-and-play experience and without the need to self-program or accessing the wire sheets on the Edge 10.  We will also provide parameters for system tuning on the CCU so direct access to the Edge 10 is not required.  All points will be viewed and configurable on the CCU and through Facilisight.

Note:

• This solution does not require an internet connection to the Edge 10, only to the CCU.
• This article only discusses the process to control the chiller, not the entire plant.
• Refer to the attached document for page number references.

System Points List:

Hardwired Inputs:

• Outdoor Air Temperature
• Chiller Supply (Leaving) Water Temperature
• Chiller Return (Entering) Water Temperature
• Optional Chiller Alarm Points (Pg. 64)

Digital Outputs:

• Chiller Enable (Pg. 63)

Analog Outputs:

• Chilled Water Supply Temperature Setpoint (Pg. 71)

Variables/Setpoints

• Supply (Leaving) Water Temperature Setpoint
• Outdoor Air Temperature for System Enable

Wiring Details