Thermo Products USDT2004 - Manual (Page 5)

5
Undo the screw at the top of the housing. The control electronics are mounted on the enclosure
cover. The controller enclosure can be screwed to the wall with cable entry grommets pointed
downwards. Use the supplied plastic bridges to secure power and sensor cables.
Base of the unit to be mounted at eye-level and wired as shown above
Caution: Controller wiring should only be done when the unit is not energized. It is possible to
damage the control unit if it is assembled under voltage. Miniaturized terminal blocks are used for
making wiring connections. The wire is held in place within the terminal with screw that provides
excellent contact without damage to the wire.
Sensor Cable Connection: Use up to an 18 AWG stranded wire to connect the sensor cables to
the unit. The S1 terminal should be connected to the collector sensor (higher temperature); the
S2 terminal is designated for the tank sensor (lower temperature). And the S3 terminal is
reserved for the advanced usage of the unit such as third temperature sensor (in program mode
1) or flow meter input for BTU operation in advanced programming mode.