Level 2 — Troubleshooting Bench
Service call CT‑401: the packaging conveyor faulted and won't restart. Diagnose it with a real Fluke 87V — set a function, pick up a lead, then probe the control terminals to find where the 24 V control voltage is lost. Every terminal is live; only the right ones reveal the fault. Then lock it out and make the repair.
Meter
Control‑panel test points conveyor dead
How this panel is fed: 120 V control power (X1/X2) comes from control transformer T1 (480:120 V), mounted above this panel and fed from the load side of the main disconnect through its own primary fuses. That is why opening the main disconnect also removes control power. The incoming protective (ground) conductor lands on the copper ground bar under the main disconnect; the bar is bolted straight to the backplate (BOND1/BOND2) and the backplate is bonded to the enclosure. Wires are identified by the number on the sleeve at each end; runs inside the covered wireways are hidden. +24 V and 0 V are distributed on jumpered terminal strips TB1 (+24 V) and TB2 (0 V): the supply feeds each strip once (FD) and every device has its own screw — one conductor per terminal. This is a training drawing: always follow the device manufacturers' terminal ratings and your site's electrical drawings.
Packaging Conveyor STOPPED
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