Installation Advice - U03B & U03C
Installation advice:
Controller installation should only be done by a qualified technician.
The wiring diagram on the box should be followed. Make sure that the sensor bulbs are placed in the correct positions. The copper sensor should be fitted in the pocket on the evaporator coil and the black sensor should be fitted in the return air.
Some mid wall units use an evaporator fan that is speed controlled via the original PC board. In this case the fan motor has only one winding, therefore only one speed will be obtained. The capacitor will need to be unsoldered from the original PC board and the wires followed to determine, the run and start windings. Normally the three thicker wires are used, and the thin wires which were originally used for the speed control are not used. If this procedure is done the fan speed terminals on the new PC board will need to be bridged so that regardless what speed the control is set to, it will still send power to the evaporator fan. To obtain different speeds a fan speed controller will need to used in conjunction with this control.
When connecting the swing function, in most cases the original plug will fit onto the plug on the PC board with one pin remaining. The two end pins are common pins and the plug can be changed in four different combinations. In most cases one of these combinations will operate the swing function correctly.