FAQ
TL;DR: With only 3 conductors at the ceiling, you get 1 circuit; two‑gang 2+2 control needs 4×1.5 mm². “The only solution… replace the cable with 4×1.5 mm.” [Elektroda, rtvserwisant, post #16675914]
Why it matters: This FAQ helps DIYers decide if their 4‑lamp ceiling light can be split 2+2 and wired safely with two switches.
Quick Facts
- Three ceiling conductors are typically L, N, and PE, which do not support independent two‑gang control. [Elektroda, rtvserwisant, post #16675992]
- Achieving 2+2 control generally requires a new 4×1.5 mm² cable run and a two‑gang switch. [Elektroda, rtvserwisant, post #16675914]
- Some 4‑lamp fittings are internally linked so all sections light together; splitting isn’t supported. [Elektroda, kindlar, post #16675318]
- If no PE is present, use a Class II (double‑insulated) luminaire or have wiring checked first. [Elektroda, Jacek Rutkowski, post #16676672]
- A loose brown lead under heat‑shrink indicates a defective crimp; return or repair the fitting. [Elektroda, kozi966, post #16675667]
Can I wire two switches to control 2+2 lamps when only 3 wires come from the ceiling?
No. A 3‑core drop (L, N, PE) supports one switched circuit. To control two groups you need a new 4×1.5 mm² cable and a compatible fitting. “The only solution… replace the cable with 4×1.5 mm.” [Elektroda, rtvserwisant, post #16675914]
Why won’t my two‑gang switch work with three ceiling conductors?
Because the three cores are L, N, and PE. A two‑gang needs two separate switched lives, plus neutral and protective earth. Replace the two‑gang with a single switch or re‑cable appropriately. [Elektroda, rtvserwisant, post #16675992]
Does the lamp itself allow splitting into 2+2?
Often no. Some luminaires link all sections internally, so all four light together. “Installation does not allow it, the lamp does not allow it.” Check the lamp’s terminals before planning. [Elektroda, kozi966, post #16675369]
What do the blue and brown wires mean in this context?
Brown is live (phase) and blue is neutral in many EU fixtures. With a single switched live, all lamp sections energize together. The post shows phase and neutral feeding the lamp simultaneously. [Elektroda, kindlar, post #16675318]
My fitting has four G9 bulbs. Do they need a driver?
If they are 230 V G9 halogens or mains‑rated LEDs, no external driver is used. They connect directly to the mains through the lamp’s terminals. Verify bulb type before wiring. [Elektroda, dkristofer, post #16675672]
How do I safely get 2+2 control on a 4‑lamp ceiling light?
Ensure your ceiling drop has two switched lives by running 4×1.5 mm². Use a two‑gang switch and a luminaire with separate live feeds for each pair. This enables independent 2+2 switching. [Elektroda, rtvserwisant, post #16675914]
What if my ceiling has no PE (earth)?
Use a Class II (double‑insulated) luminaire marked with the double‑square symbol, or have an electrician verify continuity and safety. Do not ignore missing PE on Class I metal fittings. [Elektroda, Jacek Rutkowski, post #16676672]
How can I tell if all four lamps are internally linked?
If only two terminals (L and N) exist in the lamp block and no separate feeds per section, it’s linked. The forum notes such lamps light all four together. [Elektroda, kindlar, post #16675318]
How‑To: verify what conductors you really have before wiring
- De‑energize the circuit and remove the ceiling rose or canopy.
- Identify cores and test with a meter; colors can mislead.
- Confirm presence of PE and count switched lives before choosing a switch. [Elektroda, kindlar, post #16675974]
Is a loose brown lead under heat‑shrink a safety issue?
Yes. That indicates a failed crimp connection. The fixture is considered damaged and should be returned or properly repaired before use to avoid overheating. [Elektroda, kozi966, post #16675667]
What is a two‑gang (double) switch?
It is a wall switch with two independent rockers controlling two separate lighting circuits. To use both gangs at one point, your drop must provide two switched lives. The cited post discusses the required cable. [Elektroda, rtvserwisant, post #16675914]
Edge case: My ceiling cable might be L, L, N (no PE). What then?
Colors can mislead. Measure first. Some setups route two lives and a neutral, leaving no protective earth at the point. Treat this as a limitation and plan accordingly. [Elektroda, kindlar, post #16675974]
After wiring, all four lamps light at once. Is that normal?
Yes for fixtures wired with a single live and neutral across all sections. They are internally linked, so all four illuminate together by design. [Elektroda, kindlar, post #16675318]
What symbol confirms a Class II (double‑insulated) light?
Look for two concentric squares on the rating label. This means enhanced insulation and no PE connection is required for the luminaire. [Elektroda, Jacek Rutkowski, post #16676672]
