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Verfügbare Sprachen
Verfügbare Sprachen
Scope of the test
1. Visual inspection
2. electrical test, measurement of: Protective conductor resistance, insulation resistance
or alternatively of leakage currents or open circuit voltage
3. functional test
4. Documentation
5. visual inspection
1. visual inspection
Components of the inspection are:
- Torch / electrode holder, welding current return terminal (ground terminal)
- Mains supply: Mains supply cable including plug and strain relief
- Welding circuit: cables, plugs, couplings, strain relief
- Housing
- Control and display units (front panel, display)
- General conditions
2. electrical test
Measurement of protective conductor resistance
Measurement between protective contact of the plug and touchable, conductive parts,
e.g. housing screws. During the measurement, the connecting cable must be moved along
its entire length, especially in the vicinity of the housing and plug entries. This is to detect
any interruptions in the protective conductor. Likewise, all conductive housing parts that
can be touched from the outside are to be checked to ensure a proper PE connection for
protection class I. The resistance must not exceed 0.3 Ω for a power supply cable up to 5
m in length. For longer cables, the permissible value increases by 0.1 Ω per 7.5 m cable.
The maximum permissible value is 1 Ω.
Insulation resistance measurement
In order to test the insulation inside the device up to the transformer, the mains switch
must be switched on. If there is a mains protection, it must be bridged or the
measurement must be carried out on both sides. If pole-changing switches are present,
their contacts have to be bridged so that the welding sockets have a connection to the
power section. The insulation resistance must not be less than:
Mains circuit against welding circuit and electronics: 5 M Ω.
Welding circuit and electronics against protective conductor circuit (PE): 2.5 M Ω
Mains circuit against protective conductor circuit (PE): 2.5 M Ω
Measuring the leakage current (protective conductor and touch current).
Note: Even though the leakage current measurement is only an alternative to the
insulation resistance measurement according to the standard, we recommend always
performing both measurements, especially after repairs. The leakage current is largely
based on a different physical effect than the insulation resistance. Therefore, a dangerous
leakage current may not be detected with the insulation resistance measurement. These
measurements cannot be made with a normal multimeter! Even many test devices for VDE
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