COMINOX STERILCLAVE 18 B, Service Manual

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35
Sterilisation temperature band alarm: overtemperature
/
undertemperature
Both alarms indicate that the temperature is out of the sterilising band (tolerance) defined
by EN 13060. This standard defines the tolerance band (0°C - +4°C) from the setting value
during sterilization. For example, if the setting is 134°C, the temperature should be in the
band 134°C-138°C.
The steriliser may display one of these alarms during sterilisation when the temperature in
chamber
09 and/or the theoretic steam temperature are out of the tolerance band.
This alarm could be generated by incorrect temperature and pressure values.
• If the UNDERTEMPERATURE alarm appears, check that the load weight does not exceed
the maximum value allowed (see USE AND MAINTENANCE MANUAL, chapter
OPERATING USE).
• Check steriliser temperature and pressure.
Temperature adjustment
The temperature displayed must be 0.5°C lower than the actual temperature in chamber
09 .
To adjust the temperature, firstly calibrate chamber temperature probe 39 in the
Technician Menu, options 3 (PT1 board calibration) and 7 (PT1 probe calibration).
If the temperature is still not correct, adjust the Correction parameter in the Technician
Menu (see step 1 and 2) or replace the sensor (step 3).
1. Using an external tool
- Remove the steriliser from the unit (if it is built-in) and remove the covering.
- Loosen and remove one of the
inspection plugs 40 on chamber 09 .
- Insert the probe of the external tool checking its tightness and place it in contact with the
end of chamber temperature probe 39 . Alternatively, wireless probes may be used. These
are introduced into the sterilising chamber and do not require assembly.
- Start an operating cycle and check the values. This operation should preferably be
performed with Cycle 134 HOLLOW/POROUS, because the pressure in this cycle is best
aligned to the saturated steam curve.
- Adjust the temperature using the Correction parameter in the Technical Menu (option
10).
2. Using a sample coil
-
Switch off the steriliser using main switch 13 and disconnect chamber temperature probe
39 (connector CN12 on power board 34 ).
-
Connect a sample coil with an R value from 1000 to 1573 Ohm, corresponding to a
temperature (°C) of
T = (-R0*A+(R0^2*A^2-4*R0^2*B+4*R0*R*B)^0,5)/2/R0/B
where
R0 = value of
chamber temperature probe 39 at 0°C (written on label and set in PT1
probe calibration in the Technician Menu)
A = 0,0039083
B = -0,0000005775
-
Switch on the steriliser and check the temperature value which appears on the display.
- Adjust the temperature using the Correction parameter in the Technical Menu (option
10).
Alarms