Consumer Units and Fuse Boards in Ireland
Short answer: a consumer unit, a fuse board and a distribution board are all names for the same thing, the board that takes the incoming supply and divides it into the circuits in a building. Shamrock Electrical supplies NOARK consumer units and builds equipped distribution boards to your circuit schedule. Boards are quoted rather than sold online, so use the form below or ring 01 401 9907.
What is a consumer unit?
A consumer unit is the board that takes the incoming supply and splits it into the circuits in a building, with a main switch and a protective device on every circuit.
Everything downstream of the meter runs through it. The main switch isolates the whole installation, and each way on the board carries an MCB or an RCBO sized for the cable and the load on that circuit, so a fault on one circuit is dealt with locally rather than by taking out the building.
Modern boards also carry residual current protection for shock and, increasingly, surge protection for the electronics in the building. The number of ways determines how many circuits the board can take, and it is normal to specify spare ways so a circuit can be added later without replacing the board.
Is a fuse board the same as a consumer unit?
Yes. Fuse board, fuse box, distribution board and consumer unit all describe the same piece of equipment. Fuse board is the older name, from when boards held rewireable fuses.
The names have drifted with the technology rather than the function. A board from the 1970s held porcelain carriers with fuse wire in them, and everybody called it the fuse box. Once miniature circuit breakers replaced fuse wire, consumer unit became the standard term for a domestic board, and distribution board is generally used for commercial and industrial ones.
The distinction that does matter is what is inside. A board with rewireable fuses and no residual current protection is a genuinely different level of safety from a modern board, whatever it is called.
When does a consumer unit need replacing?
When it has rewireable fuses, no RCD protection, a cracked or missing cover, signs of heat damage, or no spare ways for work the building now needs.
Rewireable fuses are the clearest case. They give no shock protection at all, and a blown fuse historically got repaired with whatever wire was to hand, which removes the protection entirely. Any board still running them is due replacement.
Heat damage is the one to take seriously. Browning around a terminal, a smell of hot plastic, or a breaker that is warm to the touch all point to a loose connection, and a loose connection in a board is a fire risk rather than an inconvenience. That is an immediate call to a contractor, not a job to plan for next year.
The less dramatic reason is capacity. A board with no spare ways forces every future addition into a workaround, and the cost of the extra ways at the time of the change is small against the cost of doing it twice.
What goes inside an equipped distribution board?
A main switch or isolator, an MCB or RCBO per circuit, residual current protection appropriate to the circuits, and increasingly a surge protection device, all assembled to your schedule.
We build with NOARK protective devices, all CE marked, manufactured to IEC and EN standards and backed by a 5 year warranty. These are the device families we build with.
Miniature circuit breakers (MCB), Ex9B125
- Rated current 16 to 100 A
- 1, 1N, 2, 3, 3N and 4 pole versions
- B, C and D tripping curves
- Breaking capacity up to 25 kA
- 230/400 V AC, tested to EN 60947-2
- Wide accessory range: auxiliary and signal contacts, shunt trip, undervoltage and overvoltage releases
Download the Ex9B125 MCB datasheet (PDF)
RCBOs, Ex9BL-H
- Residual current protection with overload protection in one device
- Rated current 6 to 40 A, 1P+N, 2 module width
- Rated residual current 30, 100 and 300 mA
- Type AC and Type A sensitivity
- Breaking capacity 10 kA, B and C curves
- Voltage independent magnetic design, to EN 61009
- Operating range minus 25 °C to plus 40 °C
Download the Ex9BL-H RCBO datasheet (PDF)
Type B RCCBs, Ex9LB63, for PV inverters and variable speed drives
Type B RCCBs detect residual AC, pulsating DC and smooth DC current, plus high frequencies up to 1 kHz, which is what is required where frequency inverters, variable speed drives and transformerless PV plant are installed. A standard Type AC or Type A device does not provide this.
- Rated current 25, 40 and 63 A
- 2 and 4 pole versions (1P+N, 3P+N)
- Rated residual current 30, 100 and 300 mA
- Conditional short circuit strength 10 kA
- 230/400 V AC, electrical trip indication
- To IEC/EN 61008-1 and IEC/EN 62423
- Electronic design for more accurate measurement and resistance to unwanted tripping
Download the Ex9LB63 Type B RCCB datasheet (PDF)
Not sure whether your job needs Type A or Type B? Read our guide: RCD types explained, Type AC vs Type A vs Type B.
Isolators and main switches, Ex9I125
- Rated current 16, 25, 32, 40, 63, 80, 100 and 125 A
- 1 to 4 pole, one module width per pole
- 230/400 V AC, short time withstand 12 times Ie for 1 s
- Built in lock mechanism for the OFF position
- Utilisation category AC-22A, mixed resistive and inductive loads
- To IEC/EN 60947-3, busbar connectable (fork or pin)
Download the Ex9I125 isolator datasheet (PDF)
Do I need a consumer unit for a garage or a shed?
Any outbuilding fed by its own submain needs a means of isolation and protection at the far end, which in practice is a small consumer unit with a main switch and a way or two.
A garage or workshop typically wants a couple of circuits, lighting and sockets, and a small board handles that cleanly while giving somebody working out there a local switch to isolate before doing anything. Running a single unprotected radial from the house board and splitting it in a junction box is how outbuildings end up unsafe.
The submain feeding it is normally armoured cable, sized for the load and the length of the run, and the earthing arrangement for a detached building needs deciding rather than assuming. That is a design question for the contractor.
Can I change a consumer unit myself?
No. Replacing or altering a consumer unit is electrical work that must be carried out and certified by a registered electrical contractor under I.S. 10101.
The reason is not bureaucratic. A board change involves working at the origin of the installation, close to the incoming supply, which does not switch off with the main switch. It also requires the whole installation to be tested afterwards, because the new protective devices have to be verified against the earth fault loop impedance actually present on each circuit.
A board that looks correct and was never tested is the dangerous outcome, because the fault it will not clear is invisible until the day it matters. Certification exists to prove the devices fitted will actually disconnect in time.
Where can I buy a consumer unit in Dublin?
At the Shamrock Electrical trade counter in Greenogue Business Park, Rathcoole, just off the N7 and well positioned for the M50. Boards are quoted rather than sold online.
Consumer units and circuit protection are not sold through the website. A board is specified rather than picked, and the way count, ratings, enclosure type and device mix all depend on the circuit schedule, so it is a conversation rather than a basket.
Equipped boards are built to order, populated, labelled and tested, so they arrive ready to install rather than as a box of parts. Website prices are retail and trade pricing is set by account and by quantity.
We have been supplying Irish contractors from Rathcoole since 2016 and hold accounts with the main manufacturers, so items not held on the shelf are usually a short order in. Ring the counter on 01 401 9907 or use the form below.
Typical build options
Boards are made to order. Common requests include:
- Surface or recessed enclosures, IP rated
- Main switch or main fuse rated to suit the supply
- Type B RCCB protection for PV inverters and variable speed drives
- Surge protection devices (SPD)
- Multi row boards, way counts configured to your circuit schedule
- Earth rod and ESB cutout arrangements
- Labelled and tested, ready to install
These boards are built to each project's requirements, so there is no fixed price shown here. Every quote is put together by our team from your specification.
Request a quote
Tell us about your project and a member of the Shamrock Electrical team will come back to you with a quotation. The more detail you give us, way count, ratings, enclosure type and the devices you want, the faster we can turn it around.
Prefer email? Contact us directly at sales@shamrockelectrical.ie.
Trade counter details
Shamrock Electrical, Unit 22, Block 613, Jordanstown Road, Greenogue Business Park, Rathcoole, Co. Dublin, D24 TX98.
Phone 01 401 9907. Email sales@shamrockelectrical.ie.
Opening hours: Monday to Friday 7am to 5pm, Saturday 9am to 1:30pm, closed Sunday.