Panasonic YD-500GP5, Operating Instructions Manual

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Maintenance and inspection
45
10.3 Precautions for withstand voltage test and insulation resistance
measurement
Make sure to work at least 5 minutes after the power is turned off.
The capacitor may still have some voltage left even if the power switch is turned off. To
prevent a physical accident caused by an electric shock or a spark,
The withstand voltage test and the insulation resistance measurement shall be performed by service engineers
specified by Panasonic representatives, or educated and/ or skilled persons who well undersand and/or who are
familiar with welders and electricity.
Performing the withstand voltage test and the insulation resistance measurement carelessly may damage this unit
as the unit is equipped with semiconductor parts including transistors.
●
If
your internal regulations define to carry out these test, observe the following ”Test preparation” and “After
completion of the test” and (The following procedure is
explained under the condition with the top panel
and the right and left panel removed.
●
Prepare jumper cables (cross section 1.25 mm2 approx.) with a clip to short-circuit each device.
●
When cables and connectors are disconnected, put tags or take notes so that they can be re-installed in place
correctly.
●
See also sections “Circuit diagram”, “Parts layout” and “Parts list”.
10.3.1
Test preparation
●
Connection
cables and signal wires
（
1
）
Turn off power at distribution box (customer preparation) and then disconnect the input cables from the load
side terminal of the distibution box and from the input power terminal of this unit. Turn off power to all related
devices (jigs).
（
2
）
Disconnect cables and signal cables connected to the following terminals and connectors.
Front: Base metal terminal (-), Torch terminal (+), Feeder connector and Base metal voltage detection terminal.
Inside: Two jig terminals
●
Primary
side
（
3
）
Short-circuit the unit input terminals collectively (total 3 terminals).
（
4
）
Turn the power switch ON side.
（
5
）
Short-circuit between the anode (wire #7) and cathode (wire #8) of the diode D1.
（
6
）
The capacitors may still have voltage. Wait for 5 minutes or more after the power is OFF before starting to
work.
（
7
）
Short-circuit load side terminal of IGBT-Q1(wire #11), load side terminal of IGBT-Q2 (wire #10), load side
terminal of IGBT-Q3 (wire #12). and load side terminal of IGBT-Q4 (wire #13).
（
8
）
Collectively short-circuit the above 3, 5 and 7.
●
Secondary side
（
9
）
For diode D2 and D3(D2,D3,D4,D5 for 500GP5),
short-circuit their own anode and cathode
respectively.
（
10
）
Short-circuit the base metal (-) terminal (128) and the torch (+) terminal (130).
●
Primary and secondary side
（
11
）
Further collectively short-circuit the above 8 and 10.
●
Case ground cable
（
12
）
Disconnect two case ground cables on the middle
plate and three case ground cables on the bottom
plate.
●
PC board
（
13
）
Disconnect all the connectors connected to the PC
board.