843 StarCool Alarm Codes

843	Economizer valve
Description	Economizer Valve Fault
Cause	Indication of non-operating economizer valve
Trouble shooting	Possible causes: Cable for economizer valve mounted on wrong valve. Cable for economizer valve defective. Economizer valve defective. Driver circuit for economizer valve defective. Trouble shooting: Try to correct the error by uploading the latest software version to the controller. If there is more than one valve failure, the cables for the valves are presumably switched. Mount cables for valves on the correct valve. Listen if the economizer valve is opening and closing. If not, then go to 5). If the valve is opening and closing, close service valve (pos. 30 P-I diagr. intermediate line). Run the FT again. If the test now is a pass, the economizer valve is defective and should be replaced. Check that the cable for the expansion valve is not defective. Replace cable if it is damaged. Disconnect the cable for valve and measure that there is voltage on the output for the expansion valve when it should open. a. If there is no voltage, the main controller is defective. Replace the main controller.
Criteria	Tsuc not changed at least 10°C (50°F) when opening economizer valve a certain time