Fronius DeltaSpot, Operating Instructions/Spare Parts List

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18
Information for di-
mensioning the
welding system
To prevent components from being overloaded, it is necessary to define the load capacity
of the inverter and the transformer in relation to each job.
Load capacity diagrams define the maximum permitted welding current in relation to the
duty cycle.
Operating points need to be defined both for the transformer and for the inverter. The lower
of the two values should be used for the application.
The duty cycle (D.C.) is calculated as follows:
D.C. = (t
1
x 100) / T
t
1
Duty time, welding time
T Cycle time
D.C. duty cycle
Example:
welding time is 180 ms and the cycle time is 4 s
The duty cycle is therefore:
D.C. = (t
1
x 100) / T = (0.18 s x 100 %) / 4 s = 4.5 %
and the maximum welding current is 17.8 kA
Diagram for dimensioning the spot welding gun
CAUTION! Overloading the welding system may result in damage to property.
Check the inverter and the transformer are configured correctly for the respective
application.
t
1
T
100
Duty cycle X in %
W
elding current (A)
4,5
10
1
30000
25000
20000
17,8 kA
15000
10000
5000
0
Transformer limiting
Welding time: 50 Per (1 s)
Welding time: 20 Per (400 ms)
Welding time: 10 Per (200 ms)