CA20 HVAC controller

The CA20 was designed for Carrier-Apac, and is used in their industrial/commercial heat pumps. Special features of this board include:

• Operates off 24VAC
• Relays for driving outdoor fans with 20A running/ 80A surge capacity.
• Relays for driving external contactors and valves, life tested by us to over 2 million operations.
• Diagnostic fault capture and display via onboard 7-segment digit.
• A number of other custom features that embody the customer's proprietary techniques.

A special feature of this project is a PC program we wrote for the customer, using SPLatLink. This gives a display of the internal operation of the controller in a readily understood format. This allows Carrier-Apac production staff to perform test their product with no intimate knowledge of the workings of the control system.