Consumer unit selection under IS 10101
A consumer unit is selected by its protection and its capacity. It needs a main switch, RCD or RCBO protection meeting the 30mA requirement for most circuits under IS 10101, and, increasingly, surge protection (an SPD). Size it for the number of circuits plus spare ways for the future, choose an enclosure suitable for its location, and have it installed and certified by a Safe Electric registered electrician. The board must comply with IS 10101 as installed, not just as bought.
The consumer unit is where an installation’s protection lives, so selecting it is really about specifying protection, capacity and compliance together. Here is how to choose one in Ireland.
What is inside a consumer unit
- A main switch to isolate the whole installation.
- Protective devices per circuit - RCBOs, or MCBs grouped under RCDs.
- 30mA RCD protection for the circuits that require it.
- Often a surge protection device (SPD).
- Spare ways for future circuits.
Protection: meeting IS 10101
IS 10101 requires 30mA RCD protection for most circuits, including socket outlets and cables concealed in walls. That drives the choice between an RCBO-per-circuit board (best selectivity) and RCDs covering groups of circuits. See our RCBO vs MCB vs RCD guide for the device detail. Surge protection is increasingly part of the specification too.
Sizing and spare capacity
Count the circuits the installation needs today, then add spare ways a board with no room to grow means a full replacement for the next circuit. A little headroom now is far cheaper than a swap later.
Enclosure and location
Choose an enclosure suited to where it goes and compliant with IS 10101. Position it for safe access and isolation. The board must be suitable for its environment, correctly rated and properly installed.
It must be installed and certified
A consumer unit change is not DIY: it must be carried out and certified by a Safe Electric registered electrician to IS 10101, with the installation tested. WEW stocks consumer units, RCBOs, RCDs and SPDs talk to the counter for the board your electrician specifies.
Frequently asked questions
How many ways should a consumer unit have?
Enough for every circuit the installation needs, plus spare ways for the future. Sizing tight to today’s circuits means replacing the board to add one later, so build in headroom.
Does a consumer unit need surge protection in Ireland?
Surge protection is increasingly part of the specification under IS 10101, provided based on a risk assessment and required in many new installations. See our surge protection guide for what the standard expects.
Can I change my own consumer unit?
No. A consumer unit change must be carried out and certified by a Safe Electric registered electrician to IS 10101, including full testing of the installation.
Source it at WEW
WEW (Waveform Electrical Wholesale) is your electrical wholesaler and lighting expert in Meath, supplying trade and homeowners across the region. Call in to the counter or the lighting showroom for stock, advice and everything referenced in this guide.