Fronius TransPocket 1500 - VRD - Voltage Reduction Device

25
The TP1500 TIG power source has an
integrated gas connection and a built-in
gas solenoid valve that permits intelligent
control of the gas flow.
This intelligent gas-flow control ensures
that the weld seam is given optimum gas-
shielding when either the “TIG welding” or
“TIG pulsed arc” welding process is
selected. Like the TIG Comfort-Stop
function, this function also does without
the torch trigger or any control leads.
As long as the welding torch touches the
component, the automatic gas pre-flow is
carried out. If the contact is kept for more
than 3 seconds, the welding current is
switched off. Place welding torch again
on the ignition point.
The gas flow is carried out until the gas
post-flow time has expired.
Gas flow
The gas post-flow time is regulated as a function of the pre-set welding current.
Depending on the pre-set welding current (10 A to 150 A), the gas post-flow time will be
between 3 and 12 seconds.
- gas post-flow time at minimum welding current (10 A) .............. 3 seconds
- gas post-flow time at maximum welding current (150A) .......... 12 seconds
Example: At a medium welding current of 70 A the gas post-flow time is 7.5 seconds.
Fig.13 shows the gas-flow control sequence where maximum welding current (150 A)
has been selected, and where the TIG Comfort-Stop function has been activated.
welding currentgas flow
150 A
t
t
fig.13 gas flow control
A B C (12 s)
2 s
A ... gas pre-flow time
B ... gas main-flow time
C ... gas post-flow time
VRD - Voltage
Reduction Device
VRD is an extra safety feature. VRD = voltage reduction device. Wherever possible,
VRD prevents output voltages which could be a hazard to life and limb.
Welding-circuit resistance is larger than
the minimum human-body resistance
(greater than or equal to 200 ohms):
- VRD is active
- Open-circuit voltage is limited to 12 V
- Example: Accidentally touching both
welding sockets at the same time
(does not lead to any hazard)
Fig.13a VRD is active