Fronius VST 247, Руководство по эксплуатации

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8
OPERATING MODES
2-STEP MODE
2-step operation is often used for tacking-jobs, short weld-seams and in
automatic welding.
INTERMITTENT 2- / 4-STEP MODE
This operating mode is used in the light-gauge sheet field; for bridging over
air gaps.
As the welding wire is not fed continuously during the welding process, but
at adjustable intervals, the welding pool has the chance to cool down in the
intermittent pause times. This generally makes it possible to avoid any local
overheating which might cause the base metal to "burn through".
The intermittent pause times can be altered with the dials “Intermittent welding
time t1” and “Intermittent pause time t2” .
4-STEP MODE
4-step mode is particularly suitable for longer weld seams.
Burn-back time correction dial ...when set correctly, the burnback time
prevents the welding wire “sticking” (setting range: 0.01 - 0.1 sec.)
Soft-start dial (optional) ... from min. to 100% of the set wirefeed speed
(recommended operating range: 50%)
Motor-speed Maximum dial ... for setting the maximum speed of the
wirefeed motor
Motor-speed Minimum dial ... for setting the minimum speed of the
wirefeed motor
Gas post-flow time setting dial ... for setting a gas post-flow time of
between 0.05 and 4 sec.
N.B.! The min. and max. motor speeds may ONLY be changed by Fronius
service personnel!
Fig.8 Functional sequence in 4-step mode
t
I
Start of cycle
Gas pre-flow time
End of welding,
incl. burn-back time
Gas post-flow time
Arc ignition
= start of welding
Welding
Press and release the torch trigger
Press and release the torch trigger again
t
I
Start of cycle
Gas pre-flow time
End of welding, incl. burn-
back time
Gas post-flow time
Arc ignition
= start of welding
Intermittent
welding time
Intermittent 4-step mode
Press and release the torch trigger
Press and release the torch trigger again
Intermittent pause time
Intermittent 2-step mode
Press and hold the torch trigger
Release the torch trigger
Fig.9 Functional sequence in intermittent 2- / 4-step mode
Fig.7 Functional sequence in 2-step mode
t
I
Start of cycle
Gas pre-flow time
End of welding,
incl. burn-
back time
Gas post-flow time
Arc ignition
= start of welding
Welding
Press and hold the torch trigger
Release the torch trigger