Fronius MTG 2100 S, Service Manual

Page: 59 / 64

Electrical tests
Ground con-
ductor resistance - The device to be tested must be safely isolated from the AC mains supply. The
mains cable (L, N, PE) and charger lead must not be connected. Follow the safety
rules.
- The measurement is taken between the ground conductor contact of the mains plug
and any touchable conductive part connected to the ground conductor. Bend, flex
and twist the mains cable during the measurement to identify any breakages in the
ground conductor.
- The measuring current must be at least 200 mA (recommendation: 10 A)
- The resistance value for a mains cable up to 5 m in length must not exceed 0.3 W
(add 0.1 W for each additional 7.5 m in length, however max. 1 W).
1 Measuring device
2 Test piece
9 Measuring line
Insulation resist-
ance
WARNING!
An electric shock can be fatal.
Some of the insulation resistance measurements are taken under high voltage.
Observe the following safety precautions:
▶
Only perform the measurement if a ground conductor resistance test has been car-
ried out successfully
▶
Do not touch any other person while performing the test and take measures to pre-
vent other people touching any metallic surfaces
▶
Ensure that the polarity is correct while conducting the insulation resistance test to
avoid unreliable test results
- The device to be tested must be safely isolated from the AC mains supply. The
mains cable (L, N, PE) and welding torch must not be connected. Follow the safety
rules.
- Power sources containing coolant must be checked with no coolant in the system.
- When measuring three-phase devices, the three-phase adapter in the basic service
equipment may be used.
- If no conductive connection exists between the current sockets and the mains plug
contacts during the measurement, then the measurement must be performed on
every current socket/line.
- With nominal (DC) power source voltages £ 500 V DC → the test voltage of the
measuring equipment is 500 V for all measurements.
The insulation resistance must not fall below the following values:
59
EN