Modes Of Operation: Cutting And Marking Mode - ESAB EPP-400 Manuel D'instructions

sectIon 4

4.2.1 Modes of operation: cutting and Marking Mode

1. The EPP-400 operates in the Cutting Mode through a single continuously adjustable output current range from 50A
through 400A using either the Current Potentiometer, on the front panel, or a remote current reference signal fed into
connector, J1.
When using a remote signal, 50A corresponds to a current reference signal of 1.00VDC, and 400A corresponds to a
signal of 8.00VDC. For signals over 8.00V, the power source internally limits the output current to a typical value of
425A.
The EPP-400 defaults to the Cutting Mode of operation unless the command signal for Marking Mode is supplied.
2. The power source is placed in Marking Mode with an external isolated relay or switch contact connecting J1-F (115VAC)
to J6-A. See Schematic Diagram included inside back cover. This contact closure must be made before (50mS or lon-
ger) issuing a Start or Contactor On command.
In the Marking Mode, the output current is adjusted through a single continuously adjustable range from 12A through
400A using either the Current Potentiometer, on the front panel, or a remote current reference signal fed into connec-
tor, J1.
When using a remote signal, 12A corresponds to a current reference signal of 0.24VDC, and 400A corresponds to a
signal of 8.00VDC. For signals over 8.00V, the power source internally limits the output current to a typical value of
425A.
In the Marking Mode, the Boost Supply, used for arc starting in the Cutting Mode, is de-activated. The resulting Open
Circuit Voltage is approximately 290V at nominal input line voltage. Additionally, K12 closes connecting R60 through
R67 into the output circuit. These resistors help stabilize the output for the low marking currents. The power source
is capable of its full 400A 100% duty output in the marking mode.
In the Marking Mode, the factory set Minimum Starting Current of 43 Amps must be reduced to 6 Amps by changing
the settings of Switch Two (SW2) on the Control PC Board mounted behind the access cover on the upper right of the
front panel. SW2 positions 5, 6, and 7 should be off (down), and position 8 should be on (up).
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operatIon