Commission the packing cell (capstone)

What you will build

Work order WO-PS-1001. Your site team, Commission the packing cell.

Meenakshi Spices, Madurai. Packing cell PC-1001 takes cartons along infeed belt TC-1001 (motor M1, 1.5 kW) to a weigh pad. A load cell amplifier WT1 gives 4 to 20 mA for 0 to 50 kg. A carton of at least 23 kg is pushed into the shipper by a pneumatic pusher Z1 on a 5/2 double-solenoid valve; a lighter carton must stop the cell with a fault. The E-STOP and the guard gate must stop the belt and the pusher together, hardwired. Control panel +F1001 has arrived with the power circuit, the 24 V supply and the analog module powered. The control wiring, the weigh loop and the air circuit are yours.

What you will learn

• Lock out and prove dead, live then dead then live
• Land 38 control conductors from a wiring schedule
• Read the supplied PLC program and match it to your wiring
• Restore power safely, test, and run the FAT

How it goes

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 33 conductors of the wiring schedule. The PLC output supply 3L+ comes through the E-STOP and the gate contacts in series (W17 to W19), so both cut every output. The inputs see the same chain on I0.2 through the signal contacts. W31 to W33 are the weigh loop.
4. Hose the air circuit, P01 to P05, with the flow controls fitted meter-out.
5. Read the supplied PLC program. It scales the counts to tenths of a kilogram, stops the belt when a carton is on the pad, weighs it after 1.5 s, and either pushes it or latches a fault.
6. Restore power: tick the checklist, remove your tag and lock, switch Q1 ON, put the PLC in RUN.
7. Test the cell: the belt, a good carton, an under-weight carton, the E-STOP and the gate, an overload trip. Then run the FAT.

Parts in the panel

• Main isolator, 4-pole, 63 A

  Switches all three phases and neutral. The incoming cable lands on 1, 3, 5, 7: those terminals stay live when it is OFF.

• MCB 2-pole, 6 A, C curve: control supply

  Feeds the 24 V power supply with 230 V (L1 and N).

• MCB 3-pole, 10 A, D curve: motor circuit

  Protects the motor circuit against short circuits. The overload relay protects the motor against overload.

• Contactor 3-pole, 9 A AC-3, coil 24 V DC, 1 NO aux

  Switches the infeed belt motor M1. Its coil gets 24 V from Q0.0 through the overload contact, with the output supply itself passing the E-STOP and the guard gate.

• Thermal overload relay, 2.5-4 A, set 3.5 A

  Trips on sustained overcurrent. 95-96 (NC) opens and 97-98 (NO) closes. Blue button: reset.

• Power supply 230 V AC to 24 V DC, 5 A

  Its 0 V (−) is bonded to PE at the factory, so 0 V and earth are the same potential.

• Analog input module, 2 channels, 4-20 mA (0 to 27648 counts)

  Channel 0 is IW64: the weigh pad signal. 4 mA (empty pad) reads 5530 counts, 20 mA (50 kg) reads 27648, and an open loop reads 0.

• PLC: compact CPU, 8 DI / 6 DQ, 24 V DC

  Inputs I0.0-I0.7 are PNP. Outputs Q0.0-Q0.5 source 24 V from 3L+, which here comes through the E-STOP and the guard gate.

• Terminal strip X2: 24 V DC distribution, 16 positions

  Positions 1 to 8 are bridged +24 V, 9 to 16 are bridged 0 V. Top and bottom of each position are the same point.

• Terminal strip X1: motor

  The motor cable from the plant lands here.

• PE bar

  Protective earth, bonded to the incoming supply's earth.

• Push button START, green, 1 NO

• Push button STOP, red, 1 NC

• Emergency stop, 2 NC, twist to release

  Contact 11-12 is in the output supply chain (3L+); 21-22 tells the PLC.

• Pilot lamp green 24 V: CELL RUNNING

• Pilot lamp amber 24 V: FAULT

• Motor 3-phase 1.5 kW, 415 V, 3.5 A, driving infeed belt TC-1001

• Weigh pad transmitter WT1, 0 to 50 kg, 4-20 mA, 2-wire, loop-powered

  Load cell amplifier under the weigh pad. 4 mA with an empty pad, 20 mA at 50 kg.

• Filter regulator, 6 bar

• 5/2 solenoid valve, double solenoid, detent

  Y1 joins P to A (extend), Y2 joins P to B (retract). With both off it stays where it was.

• Solenoid coil Y1, 24 V DC: EXTEND

• Solenoid coil Y2, 24 V DC: RETRACT

• Flow control FC1, meter-out, needle set to 30 %

  At the cap end. It sets the retract speed.

• Flow control FC2, meter-out, needle set to 30 %

  At the rod end. It sets the extend speed.

• Pusher cylinder Z1, double-acting, 40 mm bore, 300 mm stroke

• Reed switch B1, NO: closed at home (retracted)

• Reed switch B2, NO: closed at the extended end

• Guard gate interlock switch, 2 NC (11-12 safety, 21-22 signal)

  Both contacts open when the gate is opened. 11-12 is in the output supply chain, 21-22 tells the PLC.

Questions

Is it free?

Yes. The lab is free to use with a free account. There is nothing to buy to open this scenario.

Do I need to install anything?

No. It runs in your browser with a 3D panel, a circuit drawing, a meter and a PLC.

What will I do in Panel Lab 10?

You wire a control panel, then check your work against an acceptance test.

How long does it take?

Plan for one sitting. You can stop and come back.

Do I need experience?

No. Each work order says what to do step by step, and hints are there if you get stuck.