Make the right choice with consumer units
- Tuesday, August 10, 2010, 9:46
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For well over a hundred years the IEE Wiring Regulations have provided the requirements for safe electrical installations. Since the introduction of the 17th Edition (BS 7671:2008) in 2008 and the many changes to the Building Regulations, there are major implications for everyone installing consumer units. Robin Forsyth, Managing Director of Controlgear talks about making the right choice and what products you should be stocking.
Since 2005 the Building Regulations have made direct reference to electrical installations, increasing the guidelines for how electrical equipment is installed into a building. If we look at this in more detail, Part P relates to electrical installations in dwellings and states that consumer units should be located so that they are easily accessible, no greater than 1.2m high, where it is necessary to comply with Part M. Part M also states that switches, socket outlets and other equipment needs to be at appropriate heights which are defined as between 0.45m and 1.2m from the finished floor level.
In short this means that the consumer unit needs to be accessible and mounted at a height no greater than 1.2m above the floor. In addition it needs to be in a location that is easy to access – so not hidden away under the stairs.
Consumer unit selection
Having taken all this into account, we must now consider the requirements of the 17th Edition of the Wiring Regulations.
A significant change with the 17th Edition was the introduction of Regulations requiring additional protection by RCDs. This includes:
• Socket outlets for general use in a domestic installation require RCCB protection not exceeding 30mA.
• Cables buried in walls which are not mechanically protected require additional protection by an RCCB not exceeding 30mA.
• All circuits in locations containing a bath or shower must be protected by an RCCB not exceeding 30mA.
There are several ways to meet these requirements, but the most practical is to provide 30mA protection across all the circuits in the home.
The right choice
With all of this to consider, choosing the right consumer unit can be a bit of a minefield and with so many different configurations depending on application it can lead to a large amount of stock taking up space on your shelves.
The need to simplify and consolidate is something which we have considered for some time and our new 2010 QFS consumer units have been designed with this in mind.
QFS consumer units are now supplied with a metal top hat din rail making fitting of modular components easier whilst the increase in internal cabling capacity ensures that the first fix is both quick and easy.
The 17th Edition Flexi boards are fitted with two RCCBs and main switch and can now be configured on site providing the option for all circuits to be RCCB protected or unprotected ways on the main switch for RCBOs which provides individual circuit protection for circuits with switching surges or inductive loads without affecting any other circuit.
The new QFS consumer units are finished throughout in white, moulded from self extinguishing ABS and are suitable for surface mounting with the option of semi recessed in the 18 module version.
Meet the requirements
We currently offer three main solutions which meet the requirements of the 17th Edition.
Our first are the Dual Flexi units which can be configured on site as either Dual RCCB or High Integrity. This unit optimises both protection and cost with the ability to connect circuits on the main switch with intrinsically high protective earth currents, surge suppression sockets or loads with potentially high switching circuits. The two ways could, in addition be fitted with RCBOs for individual earth fault protection where tripping would not affect the other circuits.
The second solution is the Split load board which is the simplest configuration but it would need to be fitted with additional RCBO protection on the main switch to meet the requirements of the 17th Edition.
And finally we offer the main switch consumer unit fitted with single module RCBOs, providing individual circuit protection for all circuits. This means a fault on any circuit will not affect any other circuit. This configuration also makes fault finding easier although it is the most expensive option.
The main benefit to you the wholesaler is that our new 2010 range of QFS consumer units reduces the amount of stock that you need to keep. There are four Dual Flexi boards from 8-18 useable ways in the range to suit the majority of applications. This is also a great benefit for installers as they no longer need to stock a Dual RCCB board and High Integrity boards due to the flexible internal layout of the new Dual Flexi board.
Technical support
With the constant changes to the Building Regulations the task of stocking the right products has become more difficult because now you not only need to know about the products but also about how and where they can be used and which installations they are suitable for.
But despite this, with the launch of our new range we have tried to keep it simple and if you’re still unsure then we are here to help with our free technical support giving advice and help to customers.
