Troublshooting Information Page 1
Problem	Possible Cause	Solution
~ Temperature reads –327.7	~ Open Circuit	~ Check wiring from sensor to input
~ Temperature reads +372.7	~ Short Circuit	~ Check wiring from sensor to input
~ Humidity reads full scale (or any other 4-20 mamp input reads full scale.)	~ Loss of DC voltage to transducer	~ Check DC Power supply for proper input power (24 vac for a DCP 1.5W
		~ Verify 24 vdc output from power supply
		~ Check wiring from DCP to transducer
		~ Verify (-) lead is connected to any return of the controller inputs
~ Any 4-20 mamp input reads 0	~ Resistor is disconnected	~ Verify that the shunt resistor is connected (250 ohm for any TCX or LCX800, 500 ohm for any SCX920 or LCX810)
~ Input reads 999.9	~ Over voltage on an output	~ Disconnect inputs one at a time until the problem input is found.
~ Digital output not responding to command	~ HOA switch is not in the “Auto” position.	~ Verify HOA switch position on controller and at local disconnect.
	~ Control power (24 vac) not connected or fuse blown.	~ Check for control power at output common connection. Replace blown fuse. Check wiring from transformer to controller output and controlled device.
	~ AC256 series output jumper not installed on universal output.	~ Verify/replace jumper between I and +20.
~ Belimo actuators (0-10vdc) not responding to command.	~ Improper ground	~ Verify common of the three wire connection (usually #1) is connected to the same ground as the controller.
	~ Improper power connection	~ Verify 24 vac between #1 and #2 and that #1 is grounded.
	~ Blown 1/8 amp output fuse	~ Disconnect voltage lead to device. Turn output to On. Vary the potentiometer and measure the volts dc between the output and ground. Volts should vary from 0-20 vdc. Replace fuse if necessary.
	~ Improper wiring	~ Check wiring from transformer to controller output and controlled device.
~ Output transducer (4-20 mamp)	~ Improper ground	~ End device must be floating or connected to the same ground as the controller.
	~ Blown 1/8 amp output fuse	~ Disconnect lead to device. Connect volt-amp meter between current output and ground. Turn output On. Vary the potentioemeter and measure the current. Current should vary from 0-20 mamp. Replace fuse if necessary.