Fronius LaserHybrid Ultracompact Twin Operating Instructions Manual page 29

Trail wire electrode
Lead wire electrode
Active pulsed arc with droplet transfer
Inactive pulsed arc (no droplet transfer)
I Welding current of lead power source
L
I Welding current of trail power source
T
Welding direction
A "Master selection signal" is output by the robot control. This signal defines the lead power
source.
Synchronisation of both power sources:
The welding current pulses of the trail power source are placed precisely between the two
welding current pulses of the lead power source (180° phase shift).
This results in:
- Optimal material transfer (one droplet of material per welding current pulse)
- Minimal arc blow during pulsed arc
- Stable arc across the entire power range
- Reproducible process
- Excellent heat input and high welding speed
The lead wire electrode usually has a wire diameter of 1.2 mm, while the trail wire electrode
has a wire diameter of 1.0 mm.
This ensures:
- Targeted heat input
- Good melting of the cold base material
- Precise root pass formation
- Trail wire electrode fills the weld pool
- Longer degassing time (reduced proneness to porosity)
- High welding speed
NOTE! The Pulse/Pulse arc combination should be used for all general welding
applications.
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