Occupational Health, Safety and Environment: Shock, Height, PPE, LOTO, First Aid and E-Waste
This section covers occupational health, safety and environment: electrical shock prevention, working at height, PPE, lockout/tagout, first aid, and safe disposal of batteries and e-waste. The exam tests whether you can plan work that keeps DC arcs, falls and chemicals from injuring people.
Electrical safety
PV modules generate voltage whenever lit, so the DC side cannot be switched off at the source. Treat all conductors as live, isolate both positive and negative, and use DC-rated isolators. DC arcs do not self-extinguish at zero crossing, so never open a loaded DC circuit by pulling connectors. Use CAT III meters, insulated tools, remove jewellery, and keep one hand free where practicable.
Height and PPE
Use guardrails, harness and anchor points for roof work; set ladders at about 4:1 and secure them. Wear helmet, safety shoes, gloves, eye protection and arc-rated clothing as needed. Stop work in rain, lightning or high wind. Barricade ground areas below.
Lockout/tagout and first aid
LOTO: notify, isolate, lock, tag, test for dead, prove the tester, and earth where required. Inverter capacitors need discharge time. For shock: isolate safely, call emergency services, start CPR/AED if trained, and treat burns. For battery acid, flush with water.
Disposal
Lead-acid batteries, lithium batteries and PV modules are e-waste. Return them to authorised recyclers; do not dump or burn. Lithium fires need a suitable extinguisher, not water.
Worked example
A 600 V string at 10 A represents 6 kW of available DC power. At that voltage, an arc can sustain and cause severe burns even though the current is limited. The correct sequence is: shut down the inverter, open the DC isolator, lock and tag, wait for discharge, verify zero volts with a CAT III meter, then work. Pulling an MC4 first would create an arc.
Traps
Assuming DC is safer than AC; opening only the AC isolator; working alone on a roof; skipping harness anchors; putting batteries in municipal waste; using water on an electrical fire.