ESAB EPP-400 Manuel D'instructions page 311

section 6 troubleshootinG
6.10 pilot arc hi / lo and cut / mark circuits
A remote contact connecting 115V AC from J1-F to J1-L places the Pilot Arc in High by operating K8. Note, that for this func-
tion to operate, the Pilot Arc Hi/Lo switch on the front panel must be in the "LO" position.
The EPP-400 is placed in the Marking mode when a remote contact connecting 115V AC from J1-F to J6-A operates K11. In
the Marking mode, a normally closed contact on K11 opens turning off K10. When K10 turns off, the Boost supply is discon-
nected lowering the normal Cutting Mode 425V DC Open Circuit Voltage to 290V DC for Marking. A normally open contact
on K11 activates K12. K12 connects the I (min) resistors necessary for stabilizing the low currents required for marking. In
the Cutting mode, the minimum stable output current is 50A, and in the marking mode, it's 12A.
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