IKA C-MAG HS7, Manual

Page: 26 / 220

26 Start-up
/// 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 temperature 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 thermo-
meter 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).