Product manual

Welding equipment
Appendix 4
Appendix4eng_Smartac_sökfel.fm 67
10 Appendix 4
Smartac; Optimising the search circuit
The function of the Smartac is, to a great extent, dependent on the insulation
characteristics of the search circuit.
1 Water cooled gun
Distilled water or demineralizized water should be used for the best
function.
The welding gun should be filled with the water when searching. In other
words: The cooling pump should be switched on.
The above also applies when the Smartac is commissioned and the
configuration parameters for SensorSearchVoltLim and
SensorDetectionSens are determined.
2 Elimination of false search stop due to current transfer between
sensors 1 and 2.
Problems: A search stop occurs when the non active sensor attains contact
with the workpiece before the active sensor.
For example: The search stop occurs when the welding wire (sensor 2)
attains contact with the workpiece before sensor 1 (gas cup) although sensor
2 is not activated (or connected)
1
Reason: Even with relatively good insulation (>50 kOhm) between the gas
cup and welding wire there is a current transfer that will give a voltage drop
on the active sensor when the passive sensor touches the workpiece which,
if the sensitivity is too high, will give a search stop.
The reason is the high internal resistance in the sensing circuit in Smartac.
The above applies analogously for sensor 2 when it is used as the active
sensor (even if the welding circuit is isolated by a contactor).
Actions:
- It is checked when searching that a search stop does not occur if the
inactive sensor makes contact with the workpiece.
Which, for example, for sensor 1 is simply performed by connecting the
weld wire to the workpiece during the search phase and analogously for
sensor 2 connect the gas cup to the weld object during the search phase.
If a search stop occurs the configuration for "SensorDetectionSens" is
changed to a lower sensitivity (which means higher value).
Where appropriate, it may be necessary to first lower the level for
approved search voltage "SensorSearchVoltLim".
The robot system must be restarted when the configuration has been
changed (warm boot).
1. Strapping between TB 5:5 and TB 5:9 on PIB not carried out.