Safety, Environment and Workshop Practices
Safety, Environment and Workshop Practices
This domain tests safe isolation, shock protection, fire response, tool use, chemical and e-waste handling, and the workshop discipline expected in a consumer-electronics service centre.
Core rules
- Verify dead before touching: isolate, lock off, prove the tester on a known live source, test the circuit, then prove the tester again.
- Use 30 mA RCCB protection for portable tools and bench sockets. An MCB protects wiring; it does not protect people.
- Earth exposed metalwork to IS 3043 practice. Never use neutral as a substitute earth.
- Electrical fires need CO2 or dry powder, never water. Evacuate and call help for a large fire.
- Discharge power-supply and CRT/anode capacitors through a resistor, not a screwdriver.
- Solder with fume extraction. Lead-free solder needs a higher tip temperature and suitable flux.
- Wear a 1 MΩ ESD wrist strap when handling CMOS, memory and microcontroller boards.
- Segregate e-waste, lamps, batteries and solder dross and route them to authorised recyclers.
- Keep aisles clear, use insulated tools and remove jewellery before live work.
Worked example
A 230 V appliance chassis reads 90 V to earth on a 10 MΩ digital multimeter, yet the appliance works. Is it faulty? The meter forms a divider with leakage, so the reading alone does not prove a fault. Connect a low-impedance tester or insulation tester and measure insulation resistance at 500 V DC. If it is at least 1 MΩ and leakage current is below the applicable limit, the reading is probably capacitive current through a Y-capacitor. Record the test. If insulation is low, locate the leak before returning the appliance.
Traps
Assuming a neon screwdriver proves dead; fitting a bigger fuse to stop nuisance blowing; bypassing door interlocks; touching a CRT anode; treating 12 V as always safe; storing lithium cells loose.