ESAB Precision Plasmarc EPP-450 Manuel D'instructions page 39

section 6
Power Reset Fault Indicator (on front panel)
Illuminates when a serious fault is detected. Input power must be disconnected for a
least 5 seconds to clear this fault. Check PCB1 Red LEDs 6, 9, 10, 11, 12, and 13 if this
fault is illuminated for further diagnosis.
LED 6 – (red) Right Overcurrent Fault – Illuminates when the current out of the right
side chopper is too high (300 amps). This current is measured by the right-side hall
sensor. The power source is shut down.
LED 9 – (red) Left Overcurrent Fault – Illuminates when the current from the left side
chopper is too high (300 amps). Measured by the left hall sensor. Power source is
shut down.
LED 10 _ (red) Left IGBT Unsaturated Fault – Illuminates when left IGBT is not fully
conducting. PS (PS) is shut down.
LED 13 – (red) Right –(neg) 12V Bias Supply Fault - Illuminates when negative 12 V bias
supply to the right side IGBT gate drive circuit (located on PWM drive board PCB3) is
missing. PS is shut down.
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LED 11 – (red) Right IGBT Unsaturated Fault – Illuminates
when right IGBT is not fully conducting. Power Source (PS)
is shut down.
LED 12 – (red) Left -(neg) 12V Bias Supply Fault – Illuminates
when negative 12 V bias supply to the left side IGBT gate
drive circuit (located on PWM-drive board PCB2) is missing.
PS is shut down.