Domakihub How to Install a USB Wall Socket (and When to Call an Electrician)
Upgrade any wall outlet to one with built-in USB ports — here's what the job involves and who should do it.
Reviewed by Domakihub home & decor pros · 2026-06-23 · 5 min read
A USB wall socket replaces a standard power outlet with a unit that adds one or two USB-A or USB-C charging ports directly in the wall — no plug-in adapters, no clutter. The video above from This Old House walks through the swap step by step; the guide below explains the process in full, flags where Greek electrical regulations come in, and helps you decide whether this is a job for a licensed electrician or a confident DIYer. For homes, holiday rentals, and hotel rooms in Greece, the upgrade is one of the quickest wins you can make for guest comfort.
What a USB wall socket actually is
A USB combination outlet (often called a USB receptacle or USB socket) is a mains-connected device that replaces your existing socket faceplate and back-box wiring. Inside the unit, a small transformer steps the 230 V AC supply down and converts it to 5 V DC for the USB ports. The AC socket on the face continues to work exactly as before — you simply gain one or two USB ports alongside it.
There are three common types: USB-A only (older, 5 W per port), USB-A + USB-C (most popular today, up to 18 W for fast-charge), and all-USB-C (no legacy socket). For Greek properties with a mix of guest nationalities, a combo unit with at least one USB-C port and one standard Schuko socket face is the most versatile choice.
Greek electrical code and safety considerations
In Greece, residential electrical installations fall under ELOT HD 384 (equivalent to IEC 60364). Any work that involves opening a mains back-box, disconnecting live conductors, or modifying a circuit technically requires a licensed electrician (ηλεκτρολόγος with the relevant Δίπλωμα category). Practically, a simple socket-for-socket swap in an existing, properly earthed back-box is low-risk for a competent adult — but if you are renting out a property commercially (Airbnb, hotel, seasonal rental), Greek fire-safety and liability rules mean you should have the work signed off by a licensed professional. A certificate of compliance (Υπεύθυνη Δήλωση Αδειούχου Ηλεκτρολόγου) protects you if anything goes wrong.
Always check that the existing back-box has a proper earth (γείωση) wire before you buy a USB outlet — most modern USB sockets require an earth connection for the electronics inside the unit to be safe.
How to install a USB wall socket: the 5 key steps
- 1
Turn off the circuit at the consumer unit and verify it is dead
Locate the correct breaker in your fuseboard (πίνακας) and switch it off. Use a non-contact voltage tester or a plug-in socket tester on the outlet before you touch any wires. Double-check: tap the tester on the live pin of the socket — if any indicator lights, the circuit is still live and you must not proceed. This step is non-negotiable; 230 V AC is lethal.
- 2
Remove the existing socket faceplate and inspect the wiring
Unscrew the two faceplate screws and gently pull the assembly out of the back-box. You will find two or three wires: brown (live/phase), blue (neutral), and green-yellow (earth). If you see a two-wire installation with no earth, stop — you cannot safely install a USB outlet without earth. Note how the existing wires are connected (take a photo) and check the wire labels or the back of the old outlet for terminal identification.
- 3
Connect the wires to the new USB socket
USB combination outlets use clearly labelled terminals: L (live/brown), N (neutral/blue), and E or the earth symbol (green-yellow). Loosen each terminal screw, insert the stripped wire end (7–8 mm of bare copper), and tighten firmly. Do not overtighten ceramic-bodied terminals — they can crack. If the existing wire ends are corroded or too short, trim them back and re-strip with wire strippers; never use pliers. Once all three wires are seated, tug each wire gently to confirm it will not pull free.
- 4
Fold the wires back and fit the faceplate
Carefully fold the connected wires in a concertina fold into the back-box so no insulation is pinched between the faceplate and the wall. Align the socket straight (use a small spirit level if the box is recessed unevenly) and drive the two faceplate screws home. Do not overtighten — on plastered walls this cracks the faceplate; fingertight plus a quarter-turn is enough.
- 5
Restore power, test the AC socket, and test the USB ports
Switch the breaker back on. Plug a lamp or socket tester into the AC socket and confirm it works. Then plug a USB cable connected to a phone or USB meter into each USB port and confirm charging begins within a few seconds. Most USB outlets have a small LED indicator on the USB port that lights when the port is active. If nothing charges, switch off again and re-check the L and N terminal connections — reversed polarity is the most common cause.
Rather have a pro handle it?
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FAQ
- Do I need a licensed electrician to install a USB wall socket in Greece?
- For a simple like-for-like socket swap in a properly earthed back-box, the task is within reach of a careful adult who knows how to isolate a circuit and test for live voltage. However, if the property is a commercial holiday rental, hotel, or any building that requires a compliance certificate, you must have the work done or inspected by a licensed electrician (αδειούχος ηλεκτρολόγος) who can issue a signed declaration. Even outside commercial use, if you are at all unsure about the wiring condition or the presence of earth, call a professional — the cost of a single outlet change is very low.
- What is the difference between a USB-A and USB-C wall socket, and which should I choose?
- USB-A ports deliver up to 12 W and charge older phones, tablets, and accessories. USB-C ports use the Power Delivery (PD) protocol and can charge modern smartphones, tablets, and laptops at 18–65 W or more. For a Greek holiday rental or hotel room hosting international guests, choose a combo socket with at least one USB-C port (ideally 20 W or higher) and one USB-A port. That covers the widest range of current guest devices without needing adapter plugs.
- Can I install a USB socket in a bathroom or kitchen?
- Not with a standard USB outlet. Bathrooms in Greece (and under IEC 60364-7-701) are divided into zones, and the area around sinks and showers requires IP44 or higher rated devices and specific circuit protection (typically a 30 mA RCD). Standard USB wall outlets are not rated for wet zones. In kitchens, if the socket is more than 300 mm from a water source and protected by an RCD, a standard outlet is generally acceptable — but confirm with your licensed electrician before proceeding.