Level 5 of 33 · Electrical lab
Contactor with start and stop
Level 5 of 33 in the Electrical lab: a free panel wiring exercise at Intermediate level. Wire a contactor coil with a START (normally open), a STOP (normally closed) and its own hold-in contact, so a short press latches it on. Add a pilot lamp.
Goal
A contactor is a switch worked by a coil.
What you do
- Lock out the board at the isolator Q1: switch OFF, apply your lock and your tag.
- Prove it dead with the meter or the voltage tester, live-dead-live: prove the instrument on the proving unit, check the board reads 0 V, prove it again.
- Wire the 10 conductors of the schedule. STOP is normally closed (11-12) and sits first in the line, so a broken wire stops the circuit.
- Restore power: tick the checklist, remove your tag and lock, switch Q1 ON.
- Press START and let go: K1 stays in and the lamp stays on. Press STOP: both drop out. Then run the FAT.
Done when
The factory acceptance test is marked against the panel you built.
- 10 conductors in the wiring schedule
- 3 dead checks before you touch the panel
Skills
Control wiring at Intermediate level.
Before you start
Level 4, A socket on an RCD, comes first. Do it first if the ideas are new to you.
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