ESAB Precision Plasmarc EPP-600, Instruction Manual, Page: 35 / 90

35
sectIon 4 operatIon
4.2.1 Modes of operation: cutting and Marking Mode
1. The EPP-600 operates in the Cutting Mode through a single continuously adjustable output current range from 50A
through 600A using either the Current Potentiometer, on the front panel, or a remote current reference signal fed into
connector, J1.
When using a remote signal, 80A corresponds to a current reference signal of 1.00VDC, and 600A corresponds to a
signal of 7.50VDC. For signals over 8.00V, the power source internally limits the output current to a typical value of
680A.
The EPP-600 defaults to the Cutting Mode of operation unless the command signal from a remote control for Marking
Mode is supplied.
2. The power source is placed in Marking Mode with an external isolated relay or switch contact connecting J1-R (115VAC)
to J1-M. 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
600A 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 0.15VDC, and 600A corresponds to a
signal of 7.50VDC. For signals over 8.00V, the power source internally limits the output current to a typical value of
680A.
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 360V 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 600A 100% duty output in the marking mode.
12 Amp output is provided by resistors R60-R67. The factory set Minimum Starting Current (SW2) is 5 Amps. The de-
fault settings of Switch Two (SW2) on the Control PC Board mounted behind the access cover on the upper right of the
front panel is positions 5, 6, 7 and 8 are off (down).
* Approximately 310V for the 400V model.