Wiring spotlights in series: diagram and limits

Keep series wiring for very small sets: two identical spotlights, never more, on an existing supply. At 230 V, go for parallel wiring, two conductors per point. On a pre-wired 12 V kit, each spotlight starts from the same two wires: it is the driver that is unique, not the wiring.

Is it possible to wire spotlights in series?

Yes, but only for two or three identical low-power spotlights. At 230 V, the voltage is shared between the points: two spotlights means about 115 V each, far from what their electronics expect. Reserve this wiring for a repair, never for a living room.

Before running a single cable, the question is not the diagram but the number of points. Drilling six holes where two would do remains the most common mistake, and a lighting plan for your living room is precisely something to settle before buying.

With two wall lights and a pendant well placed, the designer lighting takes over the light itself and the spotlights drop back to a supporting role.

What really happens at 230 V

Each spotlight added takes its share of the voltage. The first lights dimly, the next even less, and the whole thing flickers as soon as the temperature rises.

• Voltage divider: three spotlights on 230 V receive less than 80 V each, below the starting threshold of most drivers.
• Weak link: one spotlight out of service and the whole line goes out, with no clue as to the culprit.
• Heating: the electronics work outside their range and age faster.

The case of low-voltage kits, where series wiring is not where you think

On a 12 V kit, the string connecting the spotlights is not a series connection. Each spotlight starts from the same two conductors coming from the driver: the wiring stays parallel, even if it looks like a chain.

The only unique part is the power supply. To wire an LED transformer, you add up the power of the spotlights before choosing the model.

How do you wire LED spotlights in series?

You connect the live wire of the supply to the input of the first spotlight, the output of the first to the input of the second, then the output of the last to the neutral. The current passes through each device one after the other. This requires two separate terminals per spotlight, which a screw base on a single terminal block does not allow.

The diagram, wire by wire

Allow a length of cable that runs through all the points, since the return from one spotlight becomes the supply for the next.

• Supply: the live wire joins terminal L of the first spotlight, the neutral stays waiting.
• Link: terminal N of the first runs to terminal L of the second.
• Return: terminal N of the last spotlight joins the neutral of the supply.
• Earth: continuity is never broken, it is tapped from point to point.

To wire a single spotlight, the identification is the same, except that the neutral returns directly to the supply.

What to check before cutting the cable

Switch off the circuit breaker at the consumer unit and check for absence of voltage with a voltage tester, on every conductor and not only on the live wire.

With a GU10 base, each spotlight stays independent: changing colour temperature means changing the bulb. The choice is made among GU10 LED bulbs.

Beyond eight points on the same circuit, it is better to spread them over a second line than to stack them. Have this distribution approved before drilling, or ask for advice on sizing the line.

Should spotlights be wired in series or in parallel?

In parallel, in almost every case. Each spotlight receives the full voltage, lights at its rated power and stays independent of its neighbours. Series wiring keeps only a diagnostic interest: understanding why an old line flickers or goes out on its own.

What series wiring loses

Series wiring turns a lighting line into a fragile chain, where each point depends on the previous one.

• Brightness: the shared voltage reduces the output of each spotlight, sometimes by half.
• Diagnosis: finding the faulty point means testing the line one spotlight after another.
• Blackout: one burnt-out component and the whole room goes dark.

The mechanism is identical on all light fittings: wiring a light in series produces the same symptoms on a ceiling light as on a line of spotlights.

What parallel wiring changes in practice

Each spotlight receives two conductors coming from the same supply. The voltage stays stable, and a faulty point only affects itself.

• More cable: two conductors per point, so a fuller conduit.
• Less space: the junction box grows with the number of taps.
• Isolated fault: one spotlight burnt out, the others keep lighting normally.

The full method is detailed in wiring spotlights in parallel, including tapping from terminal to terminal.

If you are still hesitating between two and four points, the collection lets you compare formats side by side before drilling: recessed LED downlights are chosen on diameter as much as on beam.

How do you wire two spotlights together, with a switch or a two-way switch?

Two spotlights on the same supply are tapped terminal to terminal: live with live, neutral with neutral, earth with earth. A simple switch cuts the live wire upstream. The two-way switch is installed between the two controls, linked by two traveller wires, with no change at the consumer unit.

Terminal to terminal on the same supply

The tap is made in a junction box, a DCL box or directly in the terminal block of the first spotlight, depending on the space available.

• Junction box: accessible, it keeps the connections inspectable.
• WAGO: quick, provided you strip a rigid conductor properly.
• DCL box: useful when the supply already has a ceiling socket.

The logic remains that of several lamps on a single supply: a single power point for everything.

Two-way switching, what changes at the consumer unit

Nothing, in the usual case. The two switches are linked to each other by the traveller wire, the live wire arrives on one side and the lamp return leaves from the other. Only the number of conductors to run increases.

To install ceiling spotlights controlled from two entry points, plan the conduit before closing the walls.

When the wiring gets heavy, a light fitting with integrated control simplifies everything. Wall lights with a switch light up on the spot, with no traveller wire to run.

What the wiring changes in the room

The wiring is not visible, the result is. An even beam, soft shadows, no dark zone between two points: that is the signature of a well-distributed circuit. Two well-placed spotlights light better than a row of six aligned at random.

Two well-placed spotlights rather than six badly distributed

You light surfaces, not points. A calculation of how many spotlights per m² gives an order of magnitude, never an obligation.

• Distance: the further apart the spotlights, the wider the beam must be.
• Angle: narrow, it sculpts materials; wide, it unifies the room.
• Orientation: adjustable for a wall, fixed above a worktop.

The light that makes you want to stay in the evening

In the evening, colour temperature decides everything. 2700 K leans towards amber and relaxes, 3000 K stays neutral, 4000 K noticeably cools a living room.

Better to mix sources than to entrust everything to the ceiling: a few spotlights for useful light, a pendant light fitting above the table, a low point for atmosphere.

An LED ceiling light keeps its place in a hallway, where you want to see clearly without thinking about it. What matters is distribution, not quantity.