Fronius TransSteel 3500 Syn, Operating Instructions Manual

Page: 27 / 144

Keylock switch An optional keylock switch is available for the power source to prevent the set-
tings from being inadvertently changed on the control panel. If the keylock
switch is in the horizontal position,
- no settings can be set on the control panel,
- only parameter settings can be retrieved,
- any assigned "Save" button can be retrieved provided that an assigned "Save"
button was selected when the keylock was enabled.
Keylock activated:
"CLO | SEd" appears on the display
Keylock deactivated:
"OP | En" appears on the display
VRD: safety
function A Voltage Reduction Device (VRD) is an optional safety device for reducing the
voltage. It is recommended for environments in which the risk of an electric
shock or electrical accident is increased considerably during arc welding:
- Due to a low human body resistance of the welder
- If the welder is exposed to a clear risk of touching the workpiece or other
parts of the welding circuit
A low human body resistance is possible when there is:
- water in the area
- humidity
- heat, particularly ambient temperatures in excess of 32°C (89.6°F)
In wet, damp or hot locations, humidity or sweat can significantly reduce the skin
resistance and the insulation resistance of protective equipment and clothing.
Such environments can include:
- Temporary dams for draining certain areas of a site during construction work
(cofferdams)
- Trenches
- Mines
- Rain
- Areas partly submerged by water
- Spraywater areas
The VRD option reduces the voltage between the electrode and the workpiece. In
safe conditions, the indicator for the currently selected welding process is per-
manently lit. A safe condition is defined as follows:
- The output voltage in an open circuit is limited to 35 V.
For as long as the welding operation is active (welding circuit resistance < 200
Ohm), the indicator of the currently selected welding process flashes and the
output voltage may exceed 35 V.
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EN