Occupational Safety, Tools, and Trade Practices
This domain tests whether you can work on an RV without harming yourself, the customer, or the unit, and whether you choose and use tools correctly. Expect questions on hazard control, lockout/tagout, WHMIS/GHS labels and safety data sheets, ladder and roof work, LP and carbon monoxide hazards, battery and 120 V shock hazards, torque practice, fastener selection, and the paperwork that records it all.
Hazard control
- Hierarchy: eliminate or substitute, then engineering controls such as ventilation and guards, then administrative controls such as procedures and signage. PPE is the last line of defence, never the only one.
- Lockout/tagout applies to every stored energy source: shore power, generator, battery banks, LP supply valves, and pressurized water.
- Verify a meter on a known live source before and after testing (live-dead-live). Treat every unknown circuit as energized.
- Two-person lift above roughly 50 lb; chocks and stands before any work under a unit.
RV-specific hazards
- Propane is heavier than air and pools in step wells and bilges; no flame testing, ever. Use soap solution or an electronic detector.
- CO from a blocked flue or an unvented appliance is invisible; never run a furnace or generator in an enclosed shop without extraction.
- Flooded batteries vent hydrogen. Charge in ventilated space, no sparks, eye protection and apron for electrolyte.
- Roof work: load-rated ladder, three-point contact, fall protection where required, and confirm the roof is walkable before stepping on it.
Tools
- Torque specs are dry or lubricated as stated. Use a calibrated wrench, pull the handle, and avoid adapters inline with the drive.
- Crimped terminals need the correct die and a pull test; solder belongs on the bench, not on a vibrating chassis.
- Multimeters carry CAT ratings: CAT III for distribution panels, CAT II for appliance circuits.
Worked example
A spec calls for 85 lb-ft and you must use a 6-inch adapter inline with an 18-inch torque wrench. Effective torque at the fastener equals setting x L / (L + E) = 85 x 18 / 24 = 63.75 lb-ft, so the fastener is under-torqued. To reach 85 lb-ft you would set 85 x 24 / 18 = 113 lb-ft, or better, remove the adapter and torque directly. An adapter at 90 degrees to the handle does not change applied torque, which is why the angle matters.
Traps
- Confusing tight with torqued. Over-torque stretches studs, warps drums, and crushes gaskets.
- Using a CAT II or unrated meter on a service panel.
- Skipping lockout because it is only 12 volts; a battery bank will arc a dropped wrench.
- Gloves or loose sleeves near a rotating fan or lathe.