Vega VEGACAP 35 Operating Instructions Manual page 22

7 Diagnostics and servicing
22
1
1 M
Fig. 9: Check the resistance in the probe
1 Contact 1 (middle pin)
2 Variable capacitor (phase)
3 Capacitor
Measure the resistance values between the following contacts with an
ohmmeter (range MΩ).
Contact 4 against contact 1 (middle pin)
The resistor must be 1 MΩ.
If the resistor is lower, this means moisture in the housing or a fault in
the electrode insulation. A possible reason could be also a non-insu-
lated electrode which is used in a conductive (humid) medium.
If the resistor is higher or if the connection is interrupted, the reason is
mostly a contact error in the adapter plate or a defective resistor due
to strong electrostatic arking.
In both cases, the probe must be repaired in our premises.
Contact 4 against vessel
The electrical connection between contact 4 and metal vessel (not
the mounting boss or probe flange) should good. Measure the resist-
ance value between contact 4 and vessel with an ohmmeter (range
very small).
•
Shortcircuit (0 ... 3 Ω) - optimum connection
•
Resistor > 3 Ω - bad connection
C PH
2 M
7
3
6
4
1 M C M
VEGACAP 35 • Relay (DPDT)
2
3