Multiquip DAW500S - Manual (Page 29)

DAW-500S WELDER/A.C. GENERATOR — PARTS & OPERATION MANUAL — REV.#0 (07/19/01) — PAGE 29
DAW-500S— WELDER/GENERATOR USE
Duty Cycle
The welder is rated at 100% duty cycle at 350 amps. Duty
Cycle refers to the amount of time the user can weld and
how long the machine must rest. The duty cycle depends
upon the welding current being used. Select the appropriate
duty cycle from Table 14 to prevent overload.
CAUTION :
FIVE ESSENTIALS FOR PROPER
WELDING PROCEDURES
Besides the steady sizzling sound that a correct arc
produces, the shape of the molten pool and the move-
ment of the metal at the rear of the pool serve as a guide
in checking weld quality. In a correctly made deposit, the
ripples produced on the bead will be uniform and the bead
will be smooth, with no overlap or undercut.
1. Correct Electrode Size
The correct choice of electrode size involves consider-
ation of a variety of factors. Such as the type, position,
and preparation of the joint, the ability of the electrode to
carry high current values without injury to the weld metal
or loss of deposition efficiency. The mass of work metal
and its ability to maintain its original properties after
welding, the characteristics of the assembly with refer-
ence to effect of stresses set up by heat application, the
practicability of heat treatment before and/or after welding,
the specific requirements as to welding quality and the
cost of achieving the desired results.
2. Correct Current
If current on equipment is too high or too low, you are
certain to be disappointed in your weld. If too high, the
electrode melts too fast and your molten pool is large and
irregular. If too low, there is not enough heat to melt the
base metal and your molten pool will be too small, will pile
up, and look irregular.
3. Correct Arc Length
If the arc is too long or voltage too high the metal melts
off the electrode in large globules which wobble from side
to side as the arc wavers, giving a wide, spattered and
irregular bead–with poor fusion between original metal and
deposited metal.
If the arc is too short or voltage too low, there is not
enough heat to melt the base metal properly and the
electrode quite often sticks to the work. This gives a high,
uneven bead, having irregular ripples and poor fusion.
4. Correct Travel Speed
When your speed is too fast: your pool does not last long
enough, impurities and gas is locked in. The bead is
narrow and ripples pointed. When speed is too slow: the
metal piles up, the bead is high and wide, with a rather
straight ripple.
5. Correct Electrode Angle
The electrode angle is of particular importance in fillet
welding and deep groove welding. Generally speaking,
when making a filet weld, the electrode should be held so
that it bisects the angle between the plates and is
perpendicular to the line of weld. If under cut occurs in the
vertical member lowers the angle of the arc and directs
the arc toward the vertical member.
Always wear welding shield with correct
filter shade when welding. Improper use,
or looking directly at the arc will lead to
blindness.
e l c y C y t u D . 4 1 e l b a T
) % ( e l c y C y t u D 0 0 1 0 8 0 6
) s p m A ( t n e r r u C s s e l r o 0 5 3 0 0 4 0 5 4
The 450 amp, 60% duty cycle referenced in
Table 14 is for CV welding ONLY.
EXAMPLE:
CAUTION :
Use protective screens or barriers to
protect others from flash and glare; warn
others not to stare at the welding arc.