CoolArc160 Low-OCV Instructor Guide

Drill

• CoolArc160 low-OCV drill
• CoolArc160 low-OCV answer key

Use This Guide For

• teaching support-power discipline on compact arc inverters
• stopping the habit of jumping straight to inverter-board replacement

Opening Prompt

• "You have a CoolArc160 with low OCV, weak strike, and fan slowdown after a short run. What do you prove before you open anything?"

What To Listen For First

• the trainee should say clamp condition, branch power quality, and fan behavior first
• the trainee should recognize that revision context matters before treating CN104 and CN108 as interchangeable

Redirect Questions

• if they jump to a board too early: "What have you proved about the clamp and fan branch so far?"
• if they get stuck: "Which document gives you the quickest split between support power and inverter output?"

Strong Answer Markers

• they start with the measurement card, not the board map
• they describe low OCV as a branch clue, not a final diagnosis
• they keep the fan-revision issue active until the machine generation is known

Common Failure Modes

• naming the inverter board before bounding the current path
• ignoring visible clamp wear because the symptom sounds electronic
• treating every fan complaint like a cooling-only issue

Debrief Notes

• reinforce that support-power complaints often present like output-stage failures on this family
• internal opening is justified only after the current path, fan branch, and support-power behavior are already bounded