Tuttnauer 3850 ELVG-D, Technician Manual

Page: 12 / 67

11
6.13 Fan is not on during the cycle
♦
Check and connect properly the FAN’S connector at JP5 on the
AJUNC3 board.
♦
Disconnect FAN and check the control TP1 and TP-13:
ON = 0.0V OFF = 5.0V
6.14 Pressure display is incorrect (discrepancy between ANALOG and
Digital displays)
♦
Re-calibrate the displayed pressure by manipulating POT2 on the
AJUNC3 board.
♦
Check the MPX2200A pressure transducer between TP2 & TP3:
♦
Working condition = 20mV for 100 kPa.
♦
If pressure transducer is faulty, replace it, and calibrate it according
to the instructions in the Chapter on Calibration.
♦
If the pressure transducer is OK but display incorrect, replace the
AJUNC3.
6.15 Temperature display is incorrect
♦
Check the temperature sensor PT100.
♦
Check the calibration of the temperature circuit.
6.16 ADD WATER (to reservoir) Indicator is always ON
♦
Check the connector at JP2 on AJUNC3 board.
♦
Check if the float at the water reservoir is stuck.
♦
Check the input: TP1 and TP8 FULL = 0.0V, EMPTY = 5.0V
♦
Check the float’s buffer, it may be, the input at U5 on PREDG is
damaged. PREDG board should be replaced.
6.17 DOOR CLOSED indicator is always ON/OFF
♦
Check and fine tune the switch at the upper front left side of the
autoclave, while the door is open. Check the switch with an
ohmmeter. If the microswitch is damaged, replace it.
♦
Check the LED, if it is burnt, change the PREDG and keypad.
♦
Check the connector between microswitch and AJUNC3 on TP2.
♦
Check the connection on GND to the microswitch with an
ohmmeter and be sure that the GND to the micro switch.
♦
If the switch and microswitch are OK, buffer at U5on PREDG may
be damaged, in that case, replace the PREDG board.
Note:
If replacing the microswitch is necessary, VERIFY THE ELECTRIC
CORD IS DISCONNECTED.
6.18 Start key does not let water into the chamber
♦
Follow previous procedures for float, controls and valve.
♦
Check the water level electrode: Connect TP1 and TP6, close the
door, press START.
♦
If 4V the electrode is short circuited or faulty. Same procedure may
be followed without pressing START, if the door is open.