Overtemperature Protection
19
MC16-EN– 1.04
9.2 Changing
the
Overtemperature Limit
Note:
If protection of the sample being processed is required, the overtemperature limit is
normally set 15
o
C above the temperature setpoint of the controller. If protection of the
furnace or oven is required, the overtemperature limit is normally set 15
o
C above the
maximum setpoint of the furnace or oven.
Start at the Home display.
Press and hold the
Overtemperature
key.
Press the
Page
key until
OT
shows on the display.
Use the
Up
and
Down arrow
keys to change the offset value– a single press shows the
current setting. To alter either keep pressed or press again.
The value will then be stored without any further input.
9.3
Checking the Overtemperature sensor temperature
Starting at the Home display.
Press and hold the Overtemperature key.
Press and hold the
Page
key for 1.5 sec.
PV
is displayed for 1 second, followed by the overtemperature sensor value for 3 seconds;
this sequence is then repeated.
9.4
Overtemperature Protection Calibration
The overtemperature protection circuit can be calibrated in the same way as can the main
controller. However, this is not normally necessary as the level of accuracy required for
overtemperature protection is not as critical as it is for the main control temperature.
Starting at the Home display.
Press and hold the Overtemperature key.
Press and hold the
Page
key for 1.5 sec.
Press the
Page
key until
CL.St
is displayed.
Now follow the procedure in section 8
Hold
Ot
Hold
pV
Hold
Hold
CL.St
Hold
