Having a bit of a brain freeze moment.
I have a 2-core SWA cable running to an outbuilding. The sheath is used to earth this cable back to the consumer unit in the house which is TNC-S, while the outbuilding has its own earth electrode (ie it's TT) protecting its Consumer Unit. That's to say I've not exported to PME to the outbuilding as it's a long way from the main building. The SWA cable is thus protected from someone putting a shovel through it by the RCD in the main building (It's a single RCD which protects all the circuits).
All well and good, but, and don't ask, I've totally blanked how to test the RCD in the house to ensure a fault with the SWA cable will trip it. As I recall I just energise the MCB covering the SWA, connect my earth lead to the disconnected earth conductor which is connected to the sheath of the SWA cable and then the line lead to the top of the RCD (Line) and do the test, repeating for the neutral.
I know I don't have to do this as such, I could just test the RCD from anywhere in the main house for the paperwork, but it's for piece of mind really that everything connecting the house to the outbuilding has been done right, and it will trip the RCD in the main house under fault conditions of the SWA.
I have a 2-core SWA cable running to an outbuilding. The sheath is used to earth this cable back to the consumer unit in the house which is TNC-S, while the outbuilding has its own earth electrode (ie it's TT) protecting its Consumer Unit. That's to say I've not exported to PME to the outbuilding as it's a long way from the main building. The SWA cable is thus protected from someone putting a shovel through it by the RCD in the main building (It's a single RCD which protects all the circuits).
All well and good, but, and don't ask, I've totally blanked how to test the RCD in the house to ensure a fault with the SWA cable will trip it. As I recall I just energise the MCB covering the SWA, connect my earth lead to the disconnected earth conductor which is connected to the sheath of the SWA cable and then the line lead to the top of the RCD (Line) and do the test, repeating for the neutral.
I know I don't have to do this as such, I could just test the RCD from anywhere in the main house for the paperwork, but it's for piece of mind really that everything connecting the house to the outbuilding has been done right, and it will trip the RCD in the main house under fault conditions of the SWA.
