ESAB Aristo RoboFeed 30-4, Service Manual

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DESCRIPTION OF OPERATION
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© ESAB AB 2014
Voltage monitoring
If the +60 V supply drops below 42 V or exceeds 78 V, the U8 displays fault code 9. This fault
does not disable any functions.
The +24 V is monitored by IC12 and potential divider R129/R130. If the voltage drops to 19.5
V or less, IC12 generates a warning signal to the processor, which responds by stopping the
wire feed and then all communication on the bus. The U8 displays fault code 4.
The +15 V is monitored by the processor and potential divider R152/R153. If the 15 V supply
drops below 13 V or exceeds 17 V, the U8 panel displays fault code 8. This fault does not
disable any functions.
13AP1:2a Start / Stop
In normal operation the Start and Stop commands come from the robot, via the CAN bus.
The welding torch switch input can be used for test purposes.
Closing the switch input activates optocoupler IC7, pulling C47 low, this generates a Start
command:
Gas pre-flow starts, then wire feed also starts and the power source generates welding
voltage. If this is not followed by a flow of welding current within three seconds, the power
source shuts down the welding power supply, although wire feed continues until the welding
torch switch is released.
13AP1:2b Monitoring the cooling water connection
The wire feed unit is equipped with a detection system ELP ( E SAB L ogic P ump) which
checks that the water hoses are connected. When connecting a water-cooled welding torch,
the water pump starts.
Micro-switch 13S1 senses whether a water-cooled welding torch is connected to the wire
feed unit: a closed switch indicates that the cooling water hoses are connected, and so
provides a Start Enable signal to the system for the water pump.
The resistors connected to input E3 form a potential divider of the 15 V supply, to produce
about +6 V for an open input.