Grant GR150 Manual De Operación página 10

3.1.3. Heater lamp
The heater lamp (orange) on the front panel indicates when the heater is on. While the bath
is warming up, the lamp is on continuously, and it starts to flash as the temperature reaches
set point. When the unit is controlling at set temperature it flashes intermittently.
3.1.4. Alarm lamp
The alarm lamp (red) on the front panel illuminates when either the liquid level is low, or the
over temperature cut-out has operated.
The low liquid level switch consists of a stainless steel float, and switches the heating and
stirring off if the liquid level falls.
When the alarm lamp is illuminated, first check the liquid level and refill if necessary. If it is
still illuminated, press the overtemperature cut-out reset, if the alarm lamp does not go out, set
overtemperature as described in 3.3.
3.1.5. Displays
3.1.4.1 LED
This display normally shows the temperature in C of liquid being controlled. It
displays set temperature when the set button "S" is pressed. The display flashes to
indicate "Set temperature" mode and will return to actual temperature after 30
seconds.
3.1.4.2 LCD
This display shows liquid temperature and set temperature at the same time. The set
temperature flashes to indicate when it is in "Set temperature" mode. It will also show
the various functions being accessed together with their values where appropriate
3.1.6. Navigation control
Press "S" to change LED display from liquid temperature to set temperature, rotate
the"Navigation control" knob to set the required operating temperature. Increasing the
speed of rotation of the knob increases the step size of the navigation control increment.
When the required temperature is indicated, press "S" again. This value is then stored in
memory and the unit will retain this value after switch off.
3.1.7. Set overtemperature control
The cut-out operating temperature is adjustable. If the liquid temperature rises above the cut-
out set temperature the heater and stirrer are switched off. To reset the cut-out push the outer
ring and release once the bath has cooled down.
Setting the overtemperature control.
There are two methods of setting the overtemperature cut out:
Option one. (Quick method)
Set the temperature to the required value and leave the bath to stabilise for at least 5 minutes
after the set point has been reached. Turn the control slowly anticlockwise, using a
screwdriver, until the alarm lamp comes on. Press the reset and at the same time turn the
control slowly clockwise until the alarm lamp goes out. This gives an overtemperature trip
point of approximately 10 to 30C above set temperature.
Option two. (Precision method)
Set the temperature to the cut out level required and leave the bath to stabilise for at least 5
minutes after the set point has been reached. Turn the control slowly anticlockwise, using a
GR150, GP200
Operating Manual
17091 Version 12 - October 2009 75T
www.grant.co.uk
EN
Page 8