Maintenance
3.1
Safety check acc. to DIN VDE 0701-0702
During the yearly maintenance and following repair we recommend an inspection acc. to DIN VDE 0701-
0702. This inspection comprises the following points:
1. Visual inspection
Check the unit and all electrical connecting lines visible damages and defects.
Replace damaged parts and electrical connecting lines.
2. Measuring the protective conductor resistance
The protective conductor resistance is measured between the grounding contacts of the
mains plug and several different, electrically conductive spots of the housing.
The measuring current for measuring the resistance must be at least 0.2 Amp.
The protective conductor resistance must not exceed the value 0.3 Ω.
Possible causes of error: corroded connections, no electrically conductive measuring spots
due to lacquer or dirt.
Cause removal: Clean connections or make the measuring spots metallically bare.
3. Measuring the insulation resistance
The insulation resistance is measured between one conduct and several different, electrical-
ly conductive spots of the housing. All switches must be closed during the measurement.
The resistance must not fall below the value 0.3 MΩ.
When measuring, make sure that the unit is not dirty or wet. If the measured resistance val-
ue is too low, we recommend drying thoroughly the unit and repeating the measurement.
4. Measuring the protective conductor current
The protective conductor current is the current that flows through the protective conductor
when the unit is switched on. All switches must be closed during the measurement.
Set the following set-point values:
•
Temperature
+90°C /
194°F
•
Humidity
90% RH
The measurement is effected at all possible plugging positions of the mains plug. The pro-
tective conductor current must not exceed 3.5 mAmp. If the current is exceeded, a possible
cause may be bad insulation or short-circuit of a coil. Coils exist e.g. in fans, mains supply
units, motors, solenoid valves, and relays. By temporary electrical uncoupling of the corre-
sponding parts, you can identify and localize possible sources of error.
Service Manual KBF (E5.2) 04-2015
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