Coltene SciCan BRAVO G4, Техническое и сервисное руководство, Страница: 99 / 116

Sterilizers Bravo G4
- TECHNICAL MANUAL
EN TECHNICAL SHEETS
97
7.5. TECHNICAL SHEET ST05 - PT1 PROBE - CHAMBER TEMPERATURE READING
WARNING:
The service activity on this component requires the side covers removal. Once the intervention
has been completed, correctly refit all covers and carry out the SAFETY TEST (including
dielectric strength and ground continuity tests).
Temperature inside the chamber is measured by a probe, termed PT1, which sits in the middle of the chamber back
wall; this position ensures more accurate readings and reduces the chances of the probe contacting the load placed
inside the chamber.
The probe is the PT1000 and features the following resistance ratings:
-
1000 Ω at 0°C (32°F)
-
1500 Ω at 130.4°C (266.72°F)
In addiction, to ensure improved accuracy, the actual resistance reading given by the sensor PT1 at 130.4°C
(266.72°F) is stamped on the probe
This value is stored in the autoclave at the factory and must be checked/modified when the probe is replaced.
The PT1 probe is connected to the general PCB, which incorporates a probe input calibration circuit, which
automatically checks calibration during operation.
Automatic input calibration is provided for the other probes as well as:
PT2 – Steam Generator,
PT3 – Chamber tube bundle heating element,
which do not require any manual setting.
SERVICE OPERATIONS
WARNING:
Before performing any type of operation on internal components, turn off the autoclave
and disconnect the mains cable.
Replacing PT1
-
Remove the right side cover and the metal rear cover to gain access to the main PCB and the rear area of the
chamber.
-
Remove the protective cover of the main PCB, which is held in place by 5 snap locks and a screw.
-
Disconnect the PT1 probe wiring from the main PCB.
-
Loosen the fastening ring nut of PT1 probe to release it completely.
-
Unscrew the nut located inside the boiler and remove the ceramic cover.
-
Slide PT1 probe, complete with ring nut, out of its seat.
-
Mark the new PT1 probe at a position 60mm (2.36 inches) away from the probe end and measure its actual
reading at 130.4°C (266.72°F), which is stamped on the wiring output terminal.
-
Fit a new fastening ring nut and a new taper fitting onto the new probe.
-
Insert the probe into its seat; making sure not to distort or bend the probe.
-
Fix the probe with the ring nut, making sure to place the mark at 60mm (2.36 inches) flush with the ring nut itself,
when the latter is tightened.
-
Position and connect the probe wiring; the connector has a mounting position, be sure to observe it.
When you have installed the new probe and refitted the board protective cover and the external covers, you will need
to check/modify the PT1 value stored at the factory as follows:
-
Activate the device.
-
Access the SETTINGS menu.
-
Access the SERVICE menu using PIN 7242.
-
Select the PT1 CALIBRATION menu.
-
Compare the value at 130.4°C (266.72°F) stored with the actual reading of the new PT1.
-
Change and confirm the new value if needed.