Understanding RCD Types:
Type AC RCDs (Standard): Type AC RCDs detect AC earth fault currents only, providing adequate protection for basic electrical circuits with resistive or inductive loads (lights, heaters, standard motors). These older-standard devices don't reliably detect DC fault currents produced by modern electronics.
- May not trip for DC fault currents from modern appliances
- Inadequate for EV chargers, variable speed motors, heat pumps
- Not suitable for circuits with significant electronic loads
- Don't meet current Standards for many applications
Type A RCDs (Modern Standard): Type A RCDs detect both AC and DC earth fault currents, providing reliable protection for modern electrical loads including variable speed motors, electronic appliances, and EV chargers. Current Australian Standards increasingly require Type A RCDs.
- EV charger circuits (mandatory)
- Washing machines, dishwashers (variable speed motors)
- Air conditioning systems
- Heat pumps and modern heating systems
- Circuits with significant electronic loads
Cost Difference: Type A RCDs cost approximately 30-50% more than Type AC devices but provide essential protection for modern electrical loads. Professional assessment determines which circuits require Type A protection versus standard Type AC.
Professional Selection: Glenn selects appropriate RCD types for specific circuits based on connected loads, ensuring adequate protection whilst managing installation costs. Mixing Type AC and Type A RCDs appropriately balances protection and budget.
