Rated Duty Cycle; Static Characteristics And Thermal Protection; Functions Of Cooling Fan - Panasonic YD-400VP1YHD Operating Instructions Manual

2.5 Rated duty cycle

CAUTION
Accumulated dust on the cooling fan(s),
heat sinks, main semiconductor(s), or
windings can reduce allowable duty cycle
or allowable weld current, which can
cause deterioration or burnout of the
welding machine. Clean these sections
periodically.
The rated duty cycle of this welding machine is
60 %. This means that the machine can weld for
a total of 6 minutes out of any 10 minutes at the
rated current, and then must cool down during
the remaining 4 minutes to prevent overheating.
Allowable duty cycle vs. Output current
(10-minute cycle, ambient temp. 40 °C)
Duty cycle (%)
Up to 308 A:100 %
100
60
Usable range
0
30
Output current (A)
As shown on the above figure, the allowable duty
cycle varies with the output current. A duty cycle on
the curved line can be calculated using the follow-
ing formula.
Allowable
Rated Output Current
Duty Cycle =
Actual Output Current
(%)
Note
• Observe the lowest allowable duty cycle of
the welding system components (typically
either the welding machine or the torch).
• Exceeding the allowable duty cycle will cause
the unit to stop automatically (with error
displayed) or burn.
• If the ambient temperature is higher than 40
°C, limit the duty cycle to a level lower than
the result of the formula.
• Output current values for pulsed welding are
the average of the base and peak current
values.
WMD078TE0PAA07
(Calculate duty cycle
using formula)
60 %
(Rated duty cycle)
308 400
2
Rated
x
Duty Cycle
(%)
2.6 Static characteristics and
thermal protection
Static characteristics
(Constant-voltage characteristics)
Voltage (V)
90
80
70
60
50
34 V
40
30
20
10
0
0 50 100 150
Thermal protection
Welding power source is equipped with a ther-
mal protection device near the heat sink of
IGBT and reactor to monitor the temperature.
The thermal protection functions when the
welding power source goes into an abnormal
temperature rise condition and stops the out-
put.
* Do not use the welding power source under
the following conditions.
• At the output voltage above the rated
value.
• With the suction opening blocked.
• Ambient temperature is above 40 °C.
• If the cooling fan does not rotate.

2.7 Functions of cooling fan

• The cooling fan starts its rotation in 13
seconds after turning on the power switch.
• The cooling fan rotates at low speed in the
standby state.
• The cooling fan stops its rotation to
conserve energy if the standby state
continues for 7 minutes or longer.
• The cooling fan rotates at high speed once
welding operation starts.
2. Specifications
200 250 300 350 400
Current (A)
11