LED Transformer Installation in Warsaw — Power Supply Connection and Mounting

LED lighting in the kitchen, inside a wardrobe, under the ceiling or on a balcony — it all runs from a transformer (power supply) that converts 230 V to 12 or 24 V. Without a properly installed transformer the strip either will not light up or will burn out. In Ursynow and Mokotow we often fit power supplies when kitchens and living rooms are being updated — clients buy the strip and we connect everything correctly.

Warning: transformer installation involves 230 V mains voltage. Incorrect wiring can cause a short circuit, electric shock or fire. Do not connect a power supply yourself unless you are confident in your skills — call a professional.

Installation cost and what affects the price

The price depends on the mounting location, cable length and installation method. If the transformer sits next to a socket the job is quick. If cable needs running through a wall, into trunking or behind a ceiling it takes longer. The power supply is purchased by the client; we connect and secure it. Fixings are included. Current prices for all electrical services are in the table.

How transformer installation works

1. We isolate the circuit the transformer will be connected to.
2. Choose the mounting location — the power supply must be in a ventilated space, not sealed in an area without airflow.
3. Secure the transformer: with screws, in trunking or on a DIN rail (depends on the model).
4. Connect the 230 V input through terminals: live, neutral, earth (if provided).
5. Connect the 12/24 V output to the LED strip or fittings, observing polarity.
6. Switch the breaker back on and test: the strip glows evenly and the transformer does not overheat.
7. Tidy cables into trunking or fix with clips; label the circuit if needed.

Common mistakes when installing an LED transformer

• Transformer chosen without a power headroom — overheats and fails within a few months. Rule of thumb: at least 20% above the total strip wattage.
• Power supply bricked into a wall or enclosed without ventilation — heats up until it shuts down or fails.
• Polarity reversed on the output — the strip does not work, or if it is RGB it lights incorrectly.
• Using 0.5 mm cable over a long run — voltage drops and the strip is dim at the far end.
• Connecting more than 5 metres of strip in series — the end overheats while the start is brighter.
• Fitting a non-waterproof transformer in a bathroom — moisture ingress, short circuit.

What to prepare before the technician arrives

• Buy a transformer with the correct wattage and voltage (12 V or 24 V — to match your strip).
• Decide where the power supply will go — near the strip or in a separate location (consumer unit, recess, cupboard).
• If cable needs routing — prepare trunking or tell the technician in advance.
• Show us where the consumer unit is and which breaker covers the lighting circuit.
• If the strip is already stuck in place — make sure its wires are brought out to the right spot.
• Provide access details: intercom code, parking, clear path to the installation point.
• If the lighting is multi-zone (kitchen + living room) — discuss the layout beforehand.
• Clarify whether a dimmer or controller is needed — this affects the transformer choice.

A real case from Warsaw

A client in Zoliborz ordered under-cabinet LED strip lighting (24 V) for his kitchen worktop. The strip was already stuck under the wall units, but the transformer was sitting loose on top of the cabinet, plugged into a regular socket. The cable was hanging down the wall. We relocated the power supply inside an upper cabinet with ventilation, wired it to a dedicated circuit from the consumer unit via Wago connectors and hid the cable in plastic trunking. We also added a switch under the cabinet for convenience. The whole job took about an hour and a half. Now no cable is dangling, the transformer is out of sight, and the lighting turns on with a single button.

Frequently asked questions

Which transformer do I need for LED strip?
It depends on the strip voltage (12 or 24 V) and total wattage. The transformer should be rated 20–30% higher than the strip’s total power draw.

Can the transformer be hidden above the ceiling?
Yes, but ventilation must be provided. A fully enclosed power supply overheats and fails quickly.

The transformer is buzzing — is that normal?
Slight buzzing in cheap models is common. If it buzzes loudly it is probably overloaded or faulty. Best to replace it.

Can the transformer be connected to a dimmer?
Only if the unit is dimmable. Standard power supplies cannot be dimmed — the strip will flicker.

Is the transformer included in the price?
No, the client supplies the power unit. We help choose the right wattage and type.

Does LED lighting need a dedicated circuit?
For short strips — not necessarily. For long runs or multiple zones it is better to add a separate breaker.

Book an LED transformer installation

We install transformers and LED lighting across Warsaw. We connect, mount and test everything. Get in touch — we will advise on the transformer and come to connect it.