Elitech STC-1000X temperature controller is a thermostat that can automatic changeover between cooling and heating. Comparing to Elitech STC-1000, STC-1000X Possess the function of Fahrenheit and Celsius conversion and have a bigger display.
During the chat with the customer, we found some interesting things. Some customes used a fan instead of a compressor to cool down. At the same time, someone was also very interested in the voltage of the output port. Among them, Mr. G Roberts is a great DIY player. We can understand the operation of STC-1000X clearly by communicating with him through emails, and tell everyone why 220V voltage cannot be measured at the output port.
Mr G Roberts
"I have purchased one of your STC-1000X digital temperature controllers and would be pleased if you can advise me on settings for the unit.
I need to control a fan unit to switch on when the temperature goes above a set point and then switch off once the temperature comes down to below the set point. The instructions indicate I need to use the “cooling” connections on the timer to do this.
I have set the temperature set point to 25 deg c and the temperature differential to 5.0 deg c, the compressor start delay is set to zero as I want to start the fan without delay. These setting, if I understand the instructions correctly should switch power to the fan at temperatures above 30 deg c and switch off at temperature below 25 deg c.
Warming the sensor so the current temperature on the display indicates in excess of the set point + temp differential I can see that the cooling indicator is on but at this point I cannot measure any power at the cooling terminals, I would expect to see 220VAC, removing the heating of the sensor and allowing to cool to ambient room temperature (below the temperature set point) the cooling indicator is off. There is no change to the reading from the terminals. I would expect to see 220VAC when the cooling indicator is on but I have nothing.
Am I setting the unit incorrectly or is the unit perhaps faulty?
Your advice would be appreciated. "
"Actually, you did a good job, the wiring is completely correct. Otherwise, the refrigeration sign will not be on."
And the reason you can't see 220V is: The output is the dry contact of the relay, and there is no 220V voltage for direct connection. Need to connect the power supply in series."
Mr G Roberts
"Many thanks for your reply. I did in fact realise what I needed to do correctly connect and control my fan just after I sent my email.
All is ok and working as I require now!"
Hope this article can help you to understand how to operate STC-1000X temeprature contoller thermostat and the relay output voltage.