Issue
Relay Control With Xenta Analog Output
Product Line
TAC Vista
Environment
- Xenta programmable controllers
- Xenta 281, 282, 283, 301, 302, 401
Cause
Occasionally installers of Xenta controllers are using the Analog Output (AO) of the Xenta controllers to control one or two external relays. This is being done when the HVAC application needs one or two more points of discrete on/off control and when the AOs are not needed for proportional control. Obviously, this deviation from normal I/O application is being entertained in a effort to avoid additional costs of higher capacity controllers and/or the Xenta I/O expansion modules. Implementation has consisted of a 12Vdc relay connected to the AO output and the AO is directed to 100% output (10V) to energize the relay and 0% output (0V) to de-energize the relay.
Resolution
While this AO relay control application has not been recommended for typical designs, it should be possible to accommodate it reliably as long as some specific considerations are included in the relay selection and installation. For more information please use the following link: Xenta Analog Output
