As-built lies: when the print and the panel disagree
Sometimes the print is wrong. Field changes, added jumpers, swapped terminals, and the wrong revision all make the drawing describe a machine that no longer exists. Learn to spot the disagreement, trust the panel, prove it, and red-line it so the next tech isn't lied to.
A faultline101 training module · the skill behind six hands-on scenarios
As-built lies: when the print and the panel disagree
Field changes, added jumpers, swapped terminals, the wrong revision — sometimes the drawing describes a machine that no longer exists. Spot the disagreement, trust the panel, prove it, red-line it.
The idea
Drawings are maintained by people, and people get busy. A wire gets moved during a breakdown, a relay gets added to solve a problem, a device gets bypassed 'temporarily' — and the print never gets updated. Now the drawing and the panel disagree, and if you trust the drawing you'll chase a machine that isn't there.
The tell is a contradiction: the print says a wire lands on terminal 14, but the panel has it on 16; the print shows a device that isn't installed, or the panel has a jumper the print doesn't. When the drawing and reality disagree, reality wins. Prove it with your meter — the copper doesn't lie — and work from what's actually in front of you.
The professional close-out is to red-line the change: mark the as-built correction on the drawing so the next person inherits the truth instead of the same trap. An undocumented modification you leave undocumented becomes the next four-hour callout — often your own.
Six faults you'll work in this module
You don't learn this by reading it — you learn it by doing it on six different faults, each drilling the same skill until it's instinct:
- The wire isn't where the print says. Fix from reality, then correct the documentation.
- An old revision. Trace the revision that matches the panel.
- A relay that isn't on the print. The change was real and useful; now it's documented.
- The device that's gone. Safety mods get restored and recorded, never left as-found.
- An hour chasing a lie. The copper doesn't lie; the drawing sometimes does.
- Cold: reconcile print and panel. Reality believed, fault fixed, documentation made honest.
The mistakes it kills
- Trusting the drawing over the panel when the two disagree
- Fixing an undocumented change but never red-lining it, so the trap stays for the next tech
- Assuming a jumper or added relay is a fault when it's an undocumented but intentional field change
Why it matters: Recognizing that the print itself is wrong — and proving and red-lining it — is what separates chasing ghosts for a shift from fixing the machine and leaving the documentation honest.
Reading about it is one thing. Doing it under pressure is another.
faultline101 drops you into a running machine with the real evidence in front of you, and the readings respond to your choices — exactly like a real callout, on equipment you can't break. This is one of 35 modules and 210 scenarios in the trainer.
Works with no signal. Install it on your phone and the whole course — 35 modules, 210 faults — comes with you into the plant.
Try the trainer free