High Temperature Cutout - Thermo Scientific NESLAB EX Series Installation, Operation And Maintanance Manual

High Temperature Cutout

(Digital One/Digital Plus)
Adjustable High Temperature Cutout
To protect your application, the adjustable High Temperature Cutout ensures
the heater will not exceed temperatures that can cause serious damage to
your unit. A single temperature sensor is located in the bath fluid. A High
Temperature fault occurs when the temperature of the sensor exceeds the set
temperature limit. The safety has a range of 0°C to 230±20°C.
In the event of a fault the unit will shut down and the controller will display HtC.
The cause of the fault must be identified and corrected before the unit can be
manually restarted.
The cutout is not preset and must be adjusted during initial installation. To set
the cutout, locate the small black adjustment dial on the rear of the controller.
Turn the dial fully clockwise and turn the power switch off then back on.
Start the unit. Adjust the setpoint for a few degrees higher than the highest
desired fluid temperature and allow the bath to stabilize at the temperature
setpoint. Turn the dial counterclockwise until you hear a click and the unit
shuts down.
Before you can restart the bath it has to cool down a few degrees. Then,
without moving the adjustment dial, turn the power switch off then back on.
NOTE: We recommend rechecking operation if the unit is moved.
High Temperature Cutout
Non-Adjustable High Temperature Cutout
For added safety, the unit also has a non-adjustable High Temperature Cutout.
With fluid in the bath, it is set to trip at 225°C ±8°C.
If the bath is empty, the cutout has a typical trip point of 300°C. The heater
temperature can continue to rise after the cutout trips up to approximately
314°C.
There will be no indication the High Temperature Cutout activated other than an
audible click. The unit will continue to run but the heater will no longer operate.
Service will be required.
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