I am idly contemplating how to go about automatically isolating the house power in the event of fire.
I have a TT earthing system, a 100ms 100mA 100A incomer into the house and a 16th edition split board Hager CU. All circuits in the house are protected by the split board 30ms 30mA RCD or individual 30ms 30mA RCBOs.
There is a CU in a detached garage and another in a shed and all circuits within these outbuildings have 30ms 30mA RCD or RCBO protection. The cables to these outbuildings are wired into the house CU in the non split section and are overload protected by MCBs, and from earth faults by the main incomer RCD. There is a pump in the shed that runs during the day for a pond, and associated other equipment. There is a solar PV system on the garage. All of this increases the risk of causing a fire if it malfunctioned, or exacerbate a fire if one started.
I have 12V smoke alarms in various places in the house, in the shed and in the garage wired into a Texecom Premier 48.
My thought is that in the event of a smoke alarm being activated and not reset within 30 seconds then I can set an output to toggle on the alarm panel which I could then use to "somehow" trip the incomer.
Any thoughts on how to trip the incomer safely? Is there an official way to do it? What are the issues with, for example, using a relay and resistor into one of the MCB protected circuits to pass a small current between phase and earth?
Ready for the flak!
I have a TT earthing system, a 100ms 100mA 100A incomer into the house and a 16th edition split board Hager CU. All circuits in the house are protected by the split board 30ms 30mA RCD or individual 30ms 30mA RCBOs.
There is a CU in a detached garage and another in a shed and all circuits within these outbuildings have 30ms 30mA RCD or RCBO protection. The cables to these outbuildings are wired into the house CU in the non split section and are overload protected by MCBs, and from earth faults by the main incomer RCD. There is a pump in the shed that runs during the day for a pond, and associated other equipment. There is a solar PV system on the garage. All of this increases the risk of causing a fire if it malfunctioned, or exacerbate a fire if one started.
I have 12V smoke alarms in various places in the house, in the shed and in the garage wired into a Texecom Premier 48.
My thought is that in the event of a smoke alarm being activated and not reset within 30 seconds then I can set an output to toggle on the alarm panel which I could then use to "somehow" trip the incomer.
Any thoughts on how to trip the incomer safely? Is there an official way to do it? What are the issues with, for example, using a relay and resistor into one of the MCB protected circuits to pass a small current between phase and earth?
Ready for the flak!