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Hydra 798 Iss.10 – 04/18
OVER TEMPERATURE CONTROLLER (H MODEL ONLY)
This device is an important safety feature. It has its own temperature sensor and will isolate the heater if the
temperature exceeds the set temperature. It should be set slightly higher, perhaps 10 – 20°C higher than the working
temperature or to the maximum safe temperature of the fluid in use. Whichever is the lowest value. IT MUST BE SET
IN THIS WAY TO ENSURE SAFE USE OF THE BATH. Suitably set it will allow for protection against component
failure and also operator error when setting the controller, either from the front panel or remotely from a computer.
The heat enabled beacon will be lit when the over-temperature controller is in safe mode.
Set the desired value on the lower display using the UP and DOWN keys.
OVER AND UNDER TEMPERATURE CONTROLLER (M & L MODELS)
The M model has a low temperature trip in addition to a high temperature trip. The low temperature trip will turn
the chiller off and can be used to safe guard water triple point cells or the liquid in the bath from freezing.
The high trip will isolate the heater if the bath temperature exceeds the set value.
Set the High Trip value to a suitable value, perhaps 10 – 20°C higher than the operating temperature but lower than
the flash point of the liquid. Set this value into the A1 Hi Parameter.
Set the Low Trip value to a suitable value, perhaps the minimum safe operating temperature for the calibration into
the A2 Lo Parameter.
To access these parameters press the scroll key until they appear on the lower display and modify the value shown on
the top display with the up and down keys.
OVER TEMPERATURE CONDITION
In the unlikely event of an over temperature or under temperature condition the Hydra will go to Alarm condition.
Depending which of the alarms has been triggered the unit will either disable the heater or the cooler accordingly.
The Temperature Policeman controller will identify which alarm has been triggered by the scrolling lower display.
The message will read as follows:
OVERTEMPERATURE CONDITION – ATTENTION REQUIRED
UNDERTEMPERATURE CONDITION – ATTENTION REQUIRED
The respective illuminated beacon will also switch off.
