ESAB ESP-50, Instruction Manual

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. Does air flow when “air test” switch is in test position?
a. If not, check torch consumables, replace if necessary.
b. If above items check OK , the problem is internal. Take unit to an Authorized Repair
Station for repair.
D. The Power light is on, but nothing happens when the torch switch is depressed. fault light
does not activate.
1. Check the following:
a. With the machine power on, depress the torch switch. On the control board the LED 1 should
be lit as long as the switch is depressed. If not then check:
i. Turn power off to the machine. Unplug control board. Put an ohmmeter across P5-1 and
P5- to take resistance reading. Depress torch switch. Meter should read a short. If not, then
one of the following is not working properly:
ii. Torch switch or the leads. Unplug the torch switch leads at the machine. Put a meter across
the two plug pins. Should read a short when the torch switch is depressed. If not, then either
broken switch leads or malfunctioning switch.
b. Check T transformer secondary voltages at the plugs P1 and P. Refer to system schematic.
Replace the transformer if the correct secondary voltages are not present.
c. If everything above checks out all right, then the PCB1 Control Board should be replaced.
E. fault light activates when torch switch is closed.
The fault circuit is used to monitor conditions necessary for the safe operation of the ESP-50.
The fault light will glow amber under the following conditions and operations will come to a
complete stop:
1. High/Low line voltage. The Fault Light will rapidly blink on and off (5 times per second). This indicates
that the input voltage is outside the “+” or “-” 15% safe operating range rating.
. Over Temperature. The fault light will be mostly off but will blink on for 1/10th of a second, every
second. This generally indicates that the duty cycle has been exceeded. Allow the power source to
cool before returning to operate.
a. Thermal switch may be open. It will open if the temperature at the IGBT base reaches 94°C. With
the machine power off, check the continuity between P1-1 and P1- of the control board. If the
switch is OK, then the ohmmeter should read a direct short. If not then it should read open.
b. If the switch is malfunctioning, replace it. Clean the surface of the heat sink before installing the
switch.
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