28
CALIBRATION CASE CALIWELD
EN
CHECKING A SETTING ON THE WELDING MACHINE
Extract from the resistive load note and from standard EN 50504
Before adjusting the product, you must:
3. Connect the welding machine to the resistive load with the grounding cable and the torch used. If not, use cables of the same dimension (length
and cross section),
4. plug the control of the torch trigger,
5. check that the measuring tools are connected and switched on,
6. connect and turn on the welding machine,
7.
configure the welding machine with the required process.
8. Wait 5 min.
To measure a setting:
9. Set the welding machine parameter to be checked,
10. Adjust the resistive load ,
11. Pull the trigger,
12. Measure:
- the values of the current and the conventional voltage
- the value of the wire speed at the tachometer after 10 sec (at stabilized speed).
13. Release the trigger.
1. Resistive load
The standard requires that current sources (MMA and TIG) and voltage sources (MIG) must be checked at a conventional voltage and conventional
current.
The formulas given by the standard are:
MMA & SUB ARC : U(V) = 20V + 0.04 x I(A) below 600 A
TIG : U(V) = 10V + 0.04 x I(A) below 600 A
MIG : U(V) = 14V + 0.05 x I(A) below 600 A
• For MMA and TIG welding machines, used as a current source, the voltage is adjusted using the resistive load to correspond to this conventio-
nal voltage.
• For the MIG machines, used as a voltage source, the current is adjusted using the resistive load to correspond to this conventional current.
Current (A)
MMA & SUB ARC (V)
TIG (V)
MIG (V)
40
21.6
11.6
16.0
60
22.4
12.4
17.0
80
23.2
13.2
18.0
100
24.0
14.0
19.0
150
26.0
16.0
21.5
200
28.0
18.0
24.0
250
30.0
20.0
26.5
300
32.0
22.0
29.5
400
36.0
26.0
31.0
500
40.0
30.0
39.0
600
44.0
34.0
44.0
The correlation table of conventional voltages and currents.
2. Practical use
From the table of correspondence, we can choose a current / voltage combination to realize a test and thus define the value of the resistance of
our load by the equation R = U / I.
To get the resistance closest to the chosen value, use the equation
The current / voltage combinations are given in the section «Definition of the resistors» in the CALIWELD LOAD 320A and 550A resistive load
manuals.
