From the micro-mech of an MCB to the shutter in a socket — learn each part, its terminals, and the safety rule that keeps the following circuits safe.
These are the building blocks of every circuit walkthrough — open a part to see its labelled anatomy, terminals and the rule that keeps it safe.
Stores energy chemically — and gives it back at whatever current the load demands, right up to a fault.
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Listens for the crackle of a bad connection — and trips before the arc becomes a fire.
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A solenoid that hammers a gong: the load at the far end of the doorbell circuit.
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Momentary by design: it conducts only while you hold it, which is why the bell rings once and stops.
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A switch thrown by an electromagnet — a small coil current commands a large motor current.
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A 45 A switch with a 13 A socket hung off it — the isolator for the biggest load in a kitchen.
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It chops the mains waveform instead of just switching it — which is why the lamp has to match the dimmer.
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Where the supply splits into final circuits, each with its own protection and its own switch.
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An inductive load that pulls several times its running current to start — protection has to allow for that.
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A controlled socket that talks to the car before it ever energises the cable.
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Where cables meet. Every joint has to live in an enclosure you can still open in ten years’ time.
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Turns live current into light — and the perfect first circuit to understand the live/neutral path.
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The over-current guard on every final circuit — trips when current exceeds its rating.
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The simplest control there is: it makes or breaks a single conductor — and that conductor has to be the live one.
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Sees changes in infrared, not movement — it detects a warm body crossing its beams.
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An engine turning an alternator — a separate source that must never touch the supply network.
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Watches the balance between live and neutral — any leakage to earth trips it in milliseconds.
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The 3-pole interface that lets you plug in an appliance — and the reason your board has RCD protection.
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Cells in series make the voltage, cells in parallel make the current — the frame carries neither.
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A switch that works to a clock instead of a finger — outdoor lighting that goes off on its own.
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Three terminals instead of two: two of these and a pair of strappers let you work one light from two places.
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A fixed resistance laid in a mesh — the whole floor becomes the heater, slowly.
Open anatomy →Now take an MCB, lamp and socket into ElectraSim and run the RCD socket walkthrough with live fault simulation.