Fault-find the outfeed conveyor starter

The brief

Work order

WO-PS-201

Job

Breakdown: outfeed conveyor CV-201 starter

Difficulty

Intermediate

Type of work

Fault-finding

Detail

8 faults to find, live testing, lockout and repair

Northfield Packing, packing hall. Outfeed conveyor CV-201 is driven by motor M1 (3-phase, 1.5 kW, 415 V, 3.4 A). Its starter panel +C201 is the site's standard starter, the same parts and the same circuit you may know from the pump panel. It has been in service for two years.

What you do

1. The conveyor has stopped working. The operator's report is below. You are the maintenance technician: find the fault, repair it and prove the conveyor works.
2. Observe: operate the door and watch the lamps, the 3D view and the PLC inputs and outputs. What does the panel do, and what does it not do?
3. Measure: live voltage tests are allowed, with care. Work along the circuit and find where the voltage stops, or where it should be and is not.
4. Isolate: switch off at Q1, lock and tag, and prove it dead, live-dead-live. Resistance readings are only for a dead panel.
5. Repair: replace the part or the conductor that has failed. Every spare is charged to the job, so do not change parts by guesswork.
6. Restore and prove: tick the checklist, remove your tag and lock, switch Q1 ON, check the PLC is in RUN and test on the door. Then run the FAT.

What the test checks

The factory acceptance test is marked against the panel you built. The level sets out:

• 19 conductors in the wiring schedule
• 6 dead checks before you touch the panel
• 8 possible faults, of which a job hides some for you to find and repair

In this lab

• Lock out and prove dead, live-dead-live
• Wire the backplate from the schematic
• Meter, tester, clamp and insulation tester