Service Manual for Medium Frequency Sine-wave Filters
GB-5
2.4.2
Measurements at the capacitor
Unscrew and mark connections of the capacitor at the terminal strip.
The capacity measurement must be executed as follows:
•
It is measured between two phases of the delta-connected
capacitors.
•
The following capacity value C
Meas
must result.
C
Meas
= 1,5 • C
rated
±7,5 %
•
A failure may occur if one of this three measured values
differs to the other.The capacitor must be exchanged in
accordance with chapter 3.
The high-voltage test is made dependent on the insulation tester with the following test
voltages:
Test voltage phase <-> ground
2,5 kV ac
3,5 kV dc
2.4.3
Measurement of the insulation strength
The choke can be checked with a high-voltage test on its insulation strength. The test is
done without capacitor.
Unscrew connections of the capacitor at the terminal strip
The high-voltage test is made dependent on the insulation tester with the following test
voltages:
Test voltage phase <-> phase
Test voltage phase <-> housing
2,5 kV ac
2,5 kV ac
3,5 kV dc
3,5 kV dc
2.4.4
Connection of the capacitor lines
The capacitor lines must be connected again in accordance with the marking if the tests are
without complaint. The terminals must be tightened with the following tightening torque:
Terminal strip
Tightening torque terminal strip
WFF 35
3,0…6,0 Nm
WFF 70
6,0…12 Nm
WFF 120
10…20 Nm
WFF 185
14…31 Nm
WFF 300
25…60 Nm
