What is the difference between a consumer unit and a distribution board?

Often, the terms distribution board and consumer unit are used interchangeably. However, while consumer units are a type of distribution board, not all distribution boards are consumer units.

Typically, a consumer unit is found in domestic properties, whereas a distribution board is found in commercial and industrial premises. A distribution board usually has a three-phase incoming electrical supply whereas a consumer unit always has a single-phase incoming supply.

Distribution boards are capable of handling more load than a consumer unit.

What regulations apply to distribution boards?

As an employer you need to comply with the Electricity at Work Regulations 1989, and part of this compliance is having a safe fixed electrical system for your staff and visitors to use.

Distribution boards are subject to wear and tear from maintenance and electrical loads, and over the years electrical regulations change, and so there comes a time when they naturally require replacement. 

We have a legal (and moral) obligation when installing your distribution board to ensure that all the circuits that are connected to it are safe, and that the main distribution and earthing are satisfactory. 

What’s the process and requirements involved?

The recommended first step is for us to perform a Commercial EICR (Electrical Installation Condition Report) on the distribution board, or the entire installation if you wish. 

This will enable us to detect any faults with the final circuits or issues around the main particulars of the installation that would need rectifying for us to be able to install your new distribution board.

By undertaking the EICR first we can give you a full and clear picture of all costs involved at the outset.

What standards must a distribution board meet?

For us to be able to install your new distribution board the minimum required standard for the existing installation is:

• The rating and condition of any existing equipment, including that of the distributor, are adequate.
• The earthing and bonding arrangements necessary for the safety of the alteration are adequate.
• The main earthing terminal of the installation is connected to an adequate means of earthing via a suitably sized earthing conductor.
• The main protective bonding is adequate.
• The meter tails and the distributor’s equipment have adequate current-carrying capacity.
• The polarity of the incoming supply is correct.
• Only final circuits that do not have any C1 or C2 defects can be connected to the new distribution board.
• Rubber or lead cables may not be able to be reconnected to the new distribution board.
• The distribution circuit that supplies the distribution board is adequate and has the correct overcurrent protection.

How much does a new distribution board cost?

The price for a replacement commercial distribution board really does vary significantly depending upon how many final circuits there are and how many RCBO devices are to be installed. 

A small three phase distribution board with minimal RCBO protection can start at around £900+VAT but for much larger distribution boards with more RCBO protection this can increase to over £3,500+VAT.

If you would like a quotation for a new distribution board, please request a quote and we will provide you with a fixed price.

Do I need an EICR before replacing a distribution board?

It is strongly recommended that an EICR is carried out before your distribution board is replaced so that we can highlight any defects with the existing installation in advance. 

If you have a site with multiple distribution boards, we can carry out an EICR on only the DB that you would like replacing, or the whole site, as you wish.

What if I don’t want an EICR first?

If you don’t want an EICR first, then instead we are able to carry out a pre-work survey. During this survey we will just check the items that would prevent us from installing the new distribution board itself and we will not check all the final circuits. 

If when we carry out the installation, we find that there are C1 or C2 defects on the existing circuits, then at that point additional charges would need to be agreed to rectify these, or the new circuits would not be connected to the distribution board. 

The charge for a commercial pre-work visit is £90+VAT. Please contact us if you would like to arrange one.

Why replace a distribution board?

There are a variety of reasons why you may wish to replace your distribution board such as:

• To accommodate additional load.
• So that RCD protection can be incorporated.
• The existing distribution board has been damaged or overloaded.
• To upgrade from rewireable fuses to MCBs and RCBOs.
• To enable a Satisfactory EICR.

What distribution board options are there?

All distribution board types that we install are fully compliant with BS7671: 18th edition Amendment 2 and the brands we usually fit are either Schneider or Eaton MEM.

We can incorporate RCD protection into the new distribution board for just all required circuits, or all recommended circuits as well, and leave enough spare capacity for any future additions.

Which old distribution boards should be replaced?

Typically, distribution boards that will require replacement are those that cannot incorporate RCD protection or obtain parts for, or those that are damaged or overloaded. A distribution board replacement may be a requirement to obtain a Satisfactory EICR.

How long does it take to install a new distribution board and is there any down time?

The time it takes to install a new distribution board varies significantly based on how many circuits there are to connect into it and the type of cabling the circuits are, for example SWA, or twin and earth. 

Other factors to consider are the distribution board wiring system and whether trunking will need to be adjusted or installed to accommodate the new distribution board. 

A small straightforward distribution board could be changed in 4 hours, whereas a larger distribution board could take one day. Some more complex installations may require 2 days or more.

Do you need to turn off the power to replace a distribution board?

To replace the distribution board, we need to isolate the power supply to it, so all circuits supplied by the DB will be off while we carry out the replacement.

How to order a new distribution board?

Decide if you want either an EICR or a pre-work survey and then contact us to make your booking.  We will then attend the site and conduct the visit and provide you with a quotation for the distribution board replacement.

If you are unsure or have any questions, then please contact us and we will be happy to help. 

We can give you an indicative price initially if you can provide images, please email these to us.

info@hexoelectricaltesting.co.uk

0207 315 4151