Advertisement
MOS TESTER
The MOS tester is a special instrument, and can be ordered only from ESAB's service
department in Laxå. Order number is 468 469- - 001.
Connect the instrument as follows:
Disconnect the power unit from the mains.
S
Disconnect capacitor C02 (and C03 in the LHN 200).
S
Remove the gate connections from AP01.
S
Connect the clip on the red wire to the red wire (the gate wire) on the transistor board.
S
Connect the clip on the yellow wire to the yellow wire (the source) on the transistor
S
board.
Connect the black wire to the cooling fins (drain).
S
Testing
Press the pushbutton marked TEST.
S
If the board is healthy, both the red and green LED's should flash alternately, about once
S
a second.
If the transistor board is short- - circuited, the red LED will light continuously (note that
S
the green LED may also flash, or be continuously lit.)
If the transistor board is open- - circuited, the green LED will be continuously lit.
S
Check that there is good electrical contact between the clip of the black wire and the
cooling fins.
Even if only one transistor board is indicated as faulty, both boards
Check the gate pulses from AP01 before commissioning the new transistor boards:
After replacement of the boards, the machine must be soft- - started.
cmha2de1
IMPORTANT!
must be replaced.
see instructions on page 19.
- - 24 - -
Advertisement
