ESAB Aristo Arc 4000i, Руководство по обслуживанию

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S0740 800 191/E080229/P78
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cp03f2
Checking the IGBT transistors
Check the IGBT transistors with the diode test mode of a multimeter.
CAUTION!
These components are very sensitive to static electricity (ESD). Use protective equipment
to protect against ESD. Place the transistors on a conducting and grounded surface.
Never touch the gate connections.
Short--circuit the gate and emitter connections (terminals 4 -- 5 and 6 -- 7 respectively)
before making the measurements.
Make sure that you and the short--circuiting link are not statically charged relative to the
IGBT transistor. Touch your hand and the short--circuiting link to terminals 1, 2 and 3 on the
transistor before fitting the link.
Without the short--circuiting link, the measurements will be incorrect.
Measure the transistor voltages as shown in the diagram below.
Voltage measurement for IGBT transistors. CAUTION! Beware of ESD!
It is also possible to check the IGBT transistors when they are mounted in the machine.
Short circuit the gate connections, contact TC1 and TC2 respectively TD1 and TD2 on
circuit board 15AP2, see diagram on page 29. Measure on the screws that connect the
IGBT transistors to power board 15AP1. The measuring result will be almost the same as
above, the voltages are lower: 0.1 -- 0.5 V.
If an IGBT transistor has failed, both transistors must be replaced. See also the description
on page 27.