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The temperature controller is equipped with an over-temperature protection circuit that turns off
heating any time the temperature read-out goes 10
°
C above the entered setpoint. When the
temperature cools below the 10
°
C threshold, the circuit is reset and the controller returns to
operating normally. An over-temperature condition is indicated by the display blinking the
message ‘-
AL
-‘. The over-temperature feature acts to help prevent accidents in situations where
something has gone wrong, or the controller is having difficulty maintaining temperature control.
➢
The Temperature Control Module, Heater (Tray), and RTD sensor form a closed loop
feedback system. When the controller is connected to a heater, the feedback loop should not be
broken at any point.
Over-Temperature Protection Circuit
