Fronius TransSteel 4000 Pulse, Руководство по эксплуатации

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VRD: Safety function
VRD: Safety
function The Voltage Reduction Device (VRD) is an optional safety device for voltage re-
duction. It is recommended for environments where arc welding significantly in-
creases the risk of electric shock or electrical accident:
- Due to low body resistance of the welder
- If the welder is exposed to a significant risk of touching the workpiece or
other parts of the welding circuit
A low body resistance is likely in the event of:
- Water in the environment
- Humidity
- Heat, especially at ambient temperatures above 32 °C (89.6 °F)
In wet, damp, or hot places, moisture or sweat can significantly reduce skin res-
istance, as well as the insulation resistance of protective equipment and clothing.
Such environments may include:
- Temporary dam structures for draining certain areas of a construction site
during the construction period (cofferdams)
- Ditches
- Mines
- Rain
- Areas partially covered by water
- Spray water zones
The VRD option reduces the voltage between the electrode and the workpiece. In
the safe state, the indicator for the currently selected welding process lights up
continuously. The safe state is defined as follows:
- In an open circuit, the output voltage is limited to a maximum of 35 V.
As long as the welding operation is active (welding circuit resistance < 200 ohms),
the indicator of the currently selected welding process flashes and the output
voltage can exceed 35 V.
VRD: Safety
principle The welding circuit resistance is great-
er than the minimum body resistance
(greater than or equal to 200 ohms):
- VRD is active
- Open circuit voltage is limited to
35 V
- Unintentional contact with the
output voltage does not pose any
danger
The welding circuit resistance is less
than the minimum body resistance
(less than 200 ohms):
- VRD is inactive
- No limitation of the output voltage
to ensure adequate welding power
- Example: welding start
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