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What the switches do to an R1 + R2 readingWhy does one switch read higher than the other?
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On a lighting circuit, method 1 also proves the switching. At a luminaire, operate the switch:
- Switched off, the loop is broken. The meter reads open circuit — its over-range display, something like >1.999 Ω.
- Switched back on, the reading comes back.
On two-way switching the reading also changes depending on which switch has made the circuit, because the line now runs through a strapper and back. More cable, more resistance.
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- Building Regs
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- Fundamental Inspection & Testing
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