IKA RCT basic Manual De Instrucciones página 12

Setting the safe temperature limit
The maximum achievable heating plate temperature is restricted
by an adjustable safety temperature limit. Once this limit has been
reached, the device stops heating.
The safe temperature limit must always be set at least 25
°C lower than the fire point of the media to be processed!
(acc. to EN 61010-2-010)
The adjustable maximum heating plate temperature is at least 10
°C under the set safety temperature limit.
Setting range: [50 °C] to [max. SET temperature + 50 °C]
Factory setting: [max. SET temperature + 50 °C]
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Setting the safety temperature limit
After switching on the device, the safety temperature limit can be
adjusted using a screwdriver.
Do not turn the setting screw beyond the clockwise or anticlo-
ckwise stop. This will cause irreparable damage to the potentio-
meter.
• Set the main switch to the ON position.
• Using the screwdriver supplied, turn the "Safe Temp" setting
screw to the clockwise stop.
• Use the temperature rotating / pressing knob to set the target
temperature to the desired "Safe Temperature" and wait until
the temperature is achieved.
• Turn the "Safe Temperature" setting screw slowly anticlockwise
until the heating function switches off and the display shows
Er25 .
• The "Safe Temp" value is displayed on the screen.
Setting the safety temperature limit has to be done as described.
The value "Safe Temperature" shown on the display only serves
for visualization.
Functional test: safety circuit switch-off
• Heat the device to a temperature of over 50 °C.
• Set the safety temperature limit as far to the left as possible (50
°C) and set the mains switch to the ON position.
• The display will show: Er25
Controlling the medium temperature limit using a contact thermometer
The preferable method for controlling the average temperature is
with contact thermometer. After the set point temperature has been
adjusted, this results in a short heating-up time, practically no tempe-
rature drift and only minor fluctuation in temperature.
A 6-pin jack is located on the rear side of the device for connecting
the PT 1000 series, contact thermometer or the contact plug. The
electronics of the devices returns a test current that must flow via
connector pins 3 and 5 for the heating plate to heat up.
Safety contact thermometers:
Acc. to DIN 12 878 class 2 or acc. Gerstel are connected with a three-
wire cable, the test current flows through the contact thermometer.
Safety function:
If the test current is interrupted because of e.g. breakage of contact
thermometer or falling out of the cable plug, the heating cuts off.
Contact thermometer without safety circuit:
Acc. to DIN 12 878 class 0. The device only heats if the test current
circuit is closed by an electrical connection of the plug pins 3 and 5.
2-wire connecting cables:
Connect plug pins 3 and 5 of the device plug.
3-wire connecting cables:
Here the test current circuit can also be produced in the terminal head
of the contact thermometer (connect plug pins 2 and 3).
A 3-wire cable with the required bridge is available (accessories).
Settings:
For detailed instructions for settings and limit values, please refer to
the operating manual of the device you are connecting.
The desired average temperature can be adjusted on the
contact thermometer. The required surface temperature of
the heating plate can be selected with the rotating / pressing
knob or button.
Adjusting the temperature of device to the maximum adjustable
temperature will result in the fastest possible heating time, but the
average temperature may fluctuate to values above the set-point
temperature on the contact thermometer. By adjusting the rotating /
pressing knob or button to approximately twice the set-point value of
contact thermometer (with a set-point of + 60 °C, the temperature of
device would be set to + 120 °C), you will reach a good compromise
between a fast heating time and over-shooting the set point. If you
adjust the temperature of the device to exactly the set-point tempe-
rature, the medium will not reach the set-point temperature because
some loss of the heat will always occur between the heating plate
and the medium.
If a fault occurs in the control circuit, the maximum heating
plate temperature can be adjusted with the safety tempera-
ture setting screw.
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