Commission the reversing conveyor starter

The brief

Work order

WO-PS-401

Job

Commission the reversing conveyor starter

Difficulty

Intermediate

Type of work

Commissioning

Detail

31 wires, lockout, meter checks and a PLC program

Deccan Logistics, Hosur. Transfer conveyor TC-401 moves parcels from the sorter to the despatch bays, and the belt must run both ways to clear a jam. Its motor is 2.2 kW, 415 V, 4.6 A. The starter panel +C401 has arrived with the power circuit and the 24 V supply wired. A reversing link kit, hidden in the duct, swaps two phases for K2. The control wiring is yours.

What you do

1. Lock out the panel at the main isolator Q1: switch OFF, apply your lock and your tag.
2. Prove it dead with the meter, live-dead-live.
3. Wire the 31 conductors of the wiring schedule. The PLC outputs get their 24 V (3L+) through the safety chain: E-STOP 11-12, then the overload's 95-96, then the safety bus X3. When the E-STOP is pressed or the overload trips, every output loses its power at once. The TRIP lamp is wired from F3 97-98 and does not use a PLC output.
4. K1 and K2 must never be in together: that shorts two phases through the reversing kit. Each coil circuit goes through the other contactor's NC contact (21-22), and the contactors are also interlocked mechanically.
5. Read the supplied PLC program. It lets a direction start only when the other is off and both contactors have been out for 2 s, so the motor is never plugged.
6. Restore power: tick the checklist, remove your tag and lock, switch Q1 ON, put the PLC in RUN.
7. Test: FWD, STOP, REV after the dwell, REV pressed while running forward, the E-STOP and an overload trip. Then run the FAT.

What the test checks

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

• 31 conductors in the wiring schedule
• 6 dead checks before you touch the panel

In this lab

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