ESAB Mig C420, Instruction Manual, Page: 73 / 239

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C420e
6.2 Function explanations
6.2.1 Start
When switched on, indicating lamps [4,5] are on for 2 seconds. Normally, if the
machine is not overheated, it should start to work in idle mode, which is indicated by
blinking of the supply ON lamp. The fan and the coolant pump are stopped. The fan
starts at the first start of welding. The coolant pump starts at the same moment, if it
is switched on with ELP switch on the water outlet [7].
6.2.2 Overheating protection
The power source has 2–step control of fan speed and overheating protection.
If temperature crosses the threshold point, the fan starts to run with increased
speed. If the internal temperature becomes too high, the welding is interrupted and
disabled. This state is indicated by permanent lighting of the orange indicating lamp
on the front of the unit. It resets automatically when the temperature falls down.
6.2.3 Water connection
The ESABMig C420w/C420sw have a sensor ELP, ESAB Logic Pump, which senses
whether the water hoses of the welding gun are connected. When a water cooled
welding gun is connected, the water pump is active.
It is recommended to switch the power source off by means of the mains switch
ON/OFF [1] for connecting the cooling water hoses to/from the ESABMig
C420sw/C420w.
6.2.4 Water flow guard
The machines with cooling unit (C420w/C420sw) can be fitted with a water flow
guard (option – see page 238).
The water flow guard interrupts and disables the welding in event of loss of coolant.
This state is indicated by blinking of the orange indicating lamp on the front of the
power source. If there is a lack a coolant flow, after 1 min the pump is switched off
and latched in this state. The pump restarts from that state along with start of
welding.
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