I would only duplicate RCDs in situations that I judged to be high risk.
One simple way of achieving this is to fit RCD socket outlets to sub circuits that are also RCD protected. The two devices probably wont co-ordinate, but having to reset either/both is IMHO an acceptable price to pay for increased safety.
Returning to the cruise ship on which all the engines were stopped by low oil level alarms, that was in my view a defective design. IMHO such engines should have a means of bypassing such alarms. If the ship is in danger, it is arguably preferable to allow the engine to run until destruction, rather than to risk loss of the vessel and the many lives therein by running onto rocks.
Nothing complex is needed, a simple switch behind a sealed glass panel would serve.
"IN CASE OF SERIOUS EMERGENCY, BREAK GLASS AND OPERATE SWITCH. THIS WILL ALLOW THE ENGINE TO RUN WHEN SAFETY SYSTEMS WOULD OTHERWISE PREVENT THIS. Use only if vessel is at risk. Serious damage may be caused."
I would only duplicate RCDs in situations that I judged to be high risk.
One simple way of achieving this is to fit RCD socket outlets to sub circuits that are also RCD protected. The two devices probably wont co-ordinate, but having to reset either/both is IMHO an acceptable price to pay for increased safety.
Returning to the cruise ship on which all the engines were stopped by low oil level alarms, that was in my view a defective design. IMHO such engines should have a means of bypassing such alarms. If the ship is in danger, it is arguably preferable to allow the engine to run until destruction, rather than to risk loss of the vessel and the many lives therein by running onto rocks.
Nothing complex is needed, a simple switch behind a sealed glass panel would serve.
"IN CASE OF SERIOUS EMERGENCY, BREAK GLASS AND OPERATE SWITCH. THIS WILL ALLOW THE ENGINE TO RUN WHEN SAFETY SYSTEMS WOULD OTHERWISE PREVENT THIS. Use only if vessel is at risk. Serious damage may be caused."
