Safety5 min
Lockout, voltage, A2L
The job is not worth a hospital visit. Confirm zero energy before you reach in.
Electrical
- Lock the disconnect. Prove 0 VAC load-side. Capacitors still bite after the disconnect is open.
- Treat every panel as live until your meter says otherwise. Test the meter on a known live source first.
- Single-phase 240 still has two hots. Pulling one fuse does not make the compressor safe.
Refrigerant
- Recover. Do not vent. Know the gas before you open a line.
- A2L (R-32, R-454B): no brazing on a charged system, leak-check, ventilation, and OEM charge limits.
- Nitrogen only for pressure tests. Never oxygen or compressed air on a refrigeration circuit.
Site
- Ladders, wet roofs, attic plywood. Gas: shut the cock if you smell it and cannot find the source fast.
- Write what you did. The next tech — or the lawyer — will read the ticket.