Description
2-Way Consumer Unit (Small): Compact Power Distribution
A consumer unit is the primary distribution point for electricity within a building. The 2-way consumer unit is designed for installations with limited circuit requirements.
The “Small” variant refers to units with a compact physical enclosure. While still accommodating two circuits, these units feature reduced dimensions.
This makes them ideal for installations where wall space is at a premium. Their smaller footprint allows mounting in confined spaces such as within cupboards or on narrow walls.
2-Way Consumer Unit (Small): What “2-Way” Means
The term “2-way” refers to the number of available spaces for protective devices within the enclosure. Each way can accommodate a single MCB or RCBO.
In a standard 2-way configuration, the unit typically provides:
Space for two single-pole circuit breakers
One main switch or RCD incomer depending on configuration
Neutral and earth terminal bars
DIN rail for mounting devices
This configuration is ideal for simple installations requiring just two circuits, such as one lighting circuit and one socket circuit.
2-Way Consumer Unit (Small): Compact Dimensions
The key distinction of a “small” 2-way consumer unit is its reduced physical size. These units are designed to minimize wall space occupation.
Typical dimensions for small 2-way units include:
Height: 146mm to 150mm
Width: 78mm to 80mm
Depth: 90mm to 100mm
For comparison, large-format 2-way units can measure up to 265mm in height and 176mm in width. The small versions offer significant space savings.
This compact footprint allows installation in locations where a larger unit simply would not fit, such as within small cupboards or on narrow walls.
2-Way Consumer Unit (Small): Material Options
Small-format 2-way consumer units are manufactured in two primary materials, each offering distinct advantages.
Metal Consumer Units feature robust steel construction with epoxy powder coating for durability and corrosion resistance . Metal enclosures provide excellent mechanical protection and are non-flammable, enhancing fire safety. Many are finished in RAL 7035 light grey. Metal units meet modern wiring regulations requiring non-combustible enclosures .
Plastic Consumer Units offer a lightweight and cost-effective alternative. Made from high-impact thermoplastic such as ABS, they provide good insulation properties and are highly flame retardant and impact resistant . The small-format plastic units maintain the same compact dimensions while being easy to install.
2-Way Consumer Unit (Small): Technical Specifications
Quality small 2-way consumer units include several important technical features.
Terminal Capacity: Typically accommodates 35mm² tails and 16mm² earth conductors .
IP Rating: Most indoor units carry an IP40 rating, providing protection against entry of solid objects greater than 1mm . Some garage-specific units offer IP65 for damp conditions .
Cable Entry Knockouts: Pre-formed knockouts on top and bottom surfaces allow for neat cable entry . Typically includes 1x 20mm knockout on each side.
Standards Compliance: Units should comply with BS 7671 (IET Wiring Regulations) and BS EN 61439-3 .
Warranty: Reputable manufacturers typically offer a 1-year guarantee .
2-Way Consumer Unit (Small): Common Applications
The small 2-way consumer unit is specifically designed for installations where space is limited.
Garages benefit from the compact size when wall space is occupied by shelving or storage. The unit provides power for lighting and sockets without taking up valuable room.
Sheds and Garden Rooms often have limited wall space. A small consumer unit fits neatly while providing essential circuit protection.
Workshops where every inch of wall space is used for tools and storage can accommodate these compact units.
Temporary Supplies for building sites benefit from the lightweight and portable nature of small units.
Outbuildings such as greenhouses or summer houses typically require only two circuits, making this unit ideal.
2-Way Consumer Unit (Small): Pre-Configured Options
Many small 2-way consumer units come pre-configured with protective devices for immediate installation.
A common configuration includes:
40A 30mA RCD main switch
6A MCB for lighting circuits
16A MCB for socket circuits
This ready-to-install package saves time during installation and ensures the correct protection is provided for typical outbuilding applications. The rated voltage is typically 230/400V .
2-Way Consumer Unit (Small): Installation Features
Despite their compact size, small 2-way consumer units include features that simplify installation.
Raised Interior: Many units feature a raised interior design that maximizes wiring space despite the compact external dimensions.
Pre-Fitted DIN Rail: A metal DIN rail is factory-fitted, ready for mounting protective devices .
Lightweight Construction: With weights around 760g, these units are easy to handle during installation .
Simple Mounting: The compact size means fewer fixing points and easier positioning.
2-Way Consumer Unit (Small): Quality and Compliance
Quality small-format 2-way consumer units are manufactured to meet rigorous safety and performance standards.
Standards Compliance: Units should comply with BS 7671:2008 and BS EN 61439-3 . These standards ensure the unit has been tested and proven safe for its intended application.
Material Quality: High-quality ABS material coating provides flame retardance and impact resistance . The housing maintains its integrity over years of service.
Amendment 3 Compliance: Modern units include appropriate cable entry provisions to maintain Amendment 3 integrity .
When installed by a qualified electrician in accordance with local regulations, a quality small 2-way consumer unit provides reliable, safe power distribution while occupying minimal wall space.
