6.1 BOC Inverweld 110 VRD and 140 VRD Operation
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General
The new BOC Inverweld 110 VRD and 140
VRD welding machines are fitted with an
internal VRD (Voltage reducing device) circuit
fulfilling AS 1674.2 safety requirements for VRD
operation.
The no-load voltage is required to be reduced
to 35V DC (peak) or less within 300ms time
after the weld when the load resistance
exceeds 20ohms. The BOC Inverweld with
VRD fitted does this and more. The Inverweld
VRD automatically reduces the no-load voltage
to below 31volts in 100ms when the external
welding circuit resistance is 20ohms.
The green LED-light on the front panel indicates
that the VRD is active and the unit is in the safe
mode. If the light is on the no-load voltage is
safe. During welding the green light may flicker,
which is normal.
Actual operation
The Inverweld VRD is designed as an integral
part of the unit and therefore the performance
of the Inverweld is not compromised by the
VRD functionality.
The VRD function is fully automatic and should
the green light not be on or flash in the on-load
state (i.e. when the power is on you are not
welding) please contact your nearest BOC or
BOC service technician.
