Definition | Appliances with basic insulation and an earth connection for safety. | Appliances with double or reinforced insulation, no earth connection. | Low-voltage appliances (≤50V AC) with no earth, designed for safety. |
Construction | – Three-core cable (Live, Neutral, Earth). – Exposed metal parts. – E.g., kettles, toasters, metal microphones. | – Two-core cable (Live, Neutral). – Plastic casing, double square symbol. – E.g., plastic projectors, laptops. | – Powered by SELV (Separated Extra-Low Voltage) or battery. – E.g., phone chargers, low-voltage LED lights. |
PAT Tests Required | 1. Visual Inspection 2. Earth Continuity Test 3. Insulation Resistance Test 4. Leakage Current Test (optional) | 1. Visual Inspection 2. Insulation Resistance Test 3. Touch Current Test (optional) | 1. Visual Inspection No electrical tests due to low voltage safety. |
Test Details & Limits | – Visual Inspection: Check plug, cable, casing for damage. Pass: No visible faults. – Earth Continuity: Measures resistance of earth path. Limit: ≤0.1Ω + cable resistance (typically ≤0.2Ω for 1m cord). – Insulation Resistance: Tests insulation between live parts and earth. Limit: ≥1MΩ (domestic), ≥2MΩ (commercial). – Leakage Current: Measures current to earth. Limit: ≤0.75mA (portable appliances). | – Visual Inspection: Check plug, cable, casing. Pass: No visible faults. – Insulation Resistance: Tests insulation between live parts and accessible surfaces. Limit: ≥1MΩ (domestic), ≥2MΩ (commercial). – Touch Current: Measures leakage via accessible parts. Limit: ≤0.25mA. | – Visual Inspection: Check plug, cable, casing. Pass: No visible faults. – No electrical tests, as risk is minimal due to low voltage. |
Testing Interval (Village Hall) | Every 12 months (annually) | Every 24 months, with annual visual inspections | Visual inspection annually, no electrical tests |
Justification for Interval | – Higher risk: Relies on earth connection, critical for safety in public settings. – Frequent use/movement: Kettles, microphones moved by hirers, increasing damage risk. – Public access: Village halls have untrained users, raising liability. – IET Guidance: Recommends 12-24 months for portable Class I in commercial settings; annual testing ensures compliance with HSE and insurance. – Risk assessment: Regular use in a community setting justifies shorter intervals. | – Lower risk: Double insulation reduces shock risk. – Moderate use: Projectors, laptops used less frequently, often stored safely. – IET Guidance: Suggests 24-48 months for Class II in low-risk environments; 24 months balances safety and cost. – Annual visual checks: Catch damage from public handling, sufficient for low-risk items. – Risk assessment: Less frequent electrical testing due to robust insulation. | – Minimal risk: Low voltage (≤50V AC) eliminates shock hazard. – IET Guidance: Visual inspection only, no fixed interval; annual checks align with hall maintenance. – Low usage: Chargers, lights rarely moved or damaged. – Risk assessment: Visual checks sufficient to ensure cables/plugs remain safe in a low-risk environment. |