WÄRTSILÄ VASA 6L32, Инструкция по эксплуатации

Страница: 15 / 394

00B.1.2 Main principles:
·
Prevent uncontrolled current loops
·
Prevent radiation
·
Prevent sparkles flying around
·
If convenient, disconnect all global signals like power supply, data
communication etc.
00B.1.2.1
Preventing uncontrolled current loops
Welding current path must always be checked, there should be a
straight route from the welding point back to the return connection
of the welding apparatus.
The main current is always going where it meets the lowest resis-
tance, in certain cases the return current can therefore go via
grounding wires and electronics in the control system.
To avoid this, the distance between the welding point and the return
connection clamp of the welding apparatus should always be
shortest possible and without electronic components in the return-
ing loop path.
Attention must be paid to the connectivity of the return connection
clamp, a bad contact might also cause sparkles and radiation.
00B.1.2.2
Preventing Radiation
The welding current and the arc is emitting a wide spectrum of
electromagnetic radiation. This might cause damages on sensitive
electronic equipment.
To avoid these damages all cabinets and terminal boxes must be
kept closed during the welding. Sensitive equipment can also be
protected by means of shielding with a conductive metal plate.
Also avoid having the cables of the welding apparatus going in
parallel with wires and cables in the control system. The high welding
current is easily inducting secondary currents in other conductive
materials.
00B.1.2.3
Preventing damage due to sparkles
Welding produces sparks. Few materials withstand the heat from
these sparkles. Therefore all cabinets and terminal boxes should be
kept closed during the welding. Sensors, actuators, cables and
other equipment on the engine must be properly protected.
Sparkles can also be a problem after they have cooled down, i.e.
causing short circuits, sealing problems etc.
200640 Welding Precautions Appendix B
00 - 3