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Supply polarity, not circuit polarity: the kit and where you testYour circuits are perfect. Can the polarity still be wrong?
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What this one is
Test method 1 already proved the polarity of each circuit, with Edison screw lampholders checked on their own (except E14 and E27 to BS EN 60238). That’s circuit polarity, done dead. Supply polarity is different: it checks the incoming supply, live, at the origin.
It matters because if the supply is the wrong way round, it doesn’t matter how perfect your circuits are — every one of them is wrong. Line ends up where a neutral should be. Parts that should never be live can be, and with the protective devices in the neutral, a fault may never disconnect.
It’s on EIC page 2 as “confirmation of supply polarity” — a tick, one of the boxes you left for later.
Guidance Note 3 · 2.6.12 · polarity · p.77
The kit, and where you test
An approved voltage indicator — a two-pole device that shows the voltage present. A two-pole test lamp that indicates voltage is another option. Not a single-pole tester.
Test at the origin: on the supply side of the main switch, with the main switch still locked off. You are reading what the supply delivers before it reaches anything of yours.
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