Consumer units are now required by the regulations to have the construction of non-combustible materials

The BS7671 electrical regulations were changed in 2015, requiring that any consumer unit installed must be made of non-combustible material. Which meant that thousands of plastic consumer units sitting on shelves of retailers and wholesalers were now obsolete. Therefore a lot of angry people wondering if the change necessary?

There is mixed thought on metal consumer units as they have their pros and cons, which we'll look at in a minute. Over the years the requirement of materials of consumer units has been changed from metal to plastic and back to metal. The main reason for changes in the specifications is due to incidents occurring that prompted the committee to review current regulations.

Photo courtesy of Envriograf showing how consumer units made of plastic can quickly catch on fire.

So what are the main reasons metal consumer units are required by the BS7671:

Non-Combustible (Electricians are required by the regulations to fit consumer units out of non-combustible materials which is usually metal). It's not uncommon for overheating to occur inside consumer units when faulty connections arise. Over-loads occur or general faults with circuit breakers. All of which can lead to a plastic consumer unit melting and possibly catching fire to the surrounding area.
Robust - Being made of metal they are less likely to get broken, as often consumer units are installed by electricians in cupboards, and bulky items like hoovers are shoved in. Plastic consumer units are liable to have their casing damaged.
Electricians can terminate SWA glands without using an external enclosure, which is often the case with plastic consumer units.
Holes in the consumer unit for cable access, it's less likely to affect the structural integrity.

Looking at the above, metal seems like a great choice, but of course, with most pros, there are also cons:

The most prominent con would be being made of metal, they can conduct electricity. Meaning that someone would only need to touch the unit to be electrocuted. Although consumer units are painted to prevent conductivity. Overheating could melt the paint leading to exposed conductive areas, coupled with poor connections and any chipped paint on the outside of the unit could be hazardous.
Electricians with poor workmanship could leave sharp edges when making access holes that could lead to live parts touching on the metal of the enclosure, leading to the risk of electrocution.
Often more expensive than plastic consumer units.

Loose connection caused burning in this consumer unit, which could have quickly cause a fire.

So we can see some very obvious pros that outweigh the cons of metal consumer units. Here at EDB Electrical Services we can't help but agree with the choice of the committee. Especially seeing a photo like below you can look at the hazards of plastic consumer units. In the most recent update of the BS7671, non-combustible materials are still a requirement.

An interesting note is that plastic consumer units are still for sale. Often at much lower prices than the metal alternative on auction websites and private ads. We believe that if you are getting your consumer unit changed to take in mind a few things. First and foremost make sure you are using a fully qualified and insured electrician.

Secondly, if the price is much lower than the rest of your quotes, there is always the possibility that they may be planning to install a non-compliant consumer unit. Whilst this is hazardous and potentially costly if you come to sell your house and it comes up on a survey. Here at EDB Electrical Services we only install compliant, top quality products to ensure years of life for the user and the equipment.

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- 18th Edition Wiring Regulations Changes OverviewMarch 26, 2018Electrical Guidance / Latest news & UpdatesThe 18th edition wiring regulations changes are set to come into effect on the 1st July 2018. The previous IET wiring regulations (17th edition 3rd amendment) will cease to be the latest standard. The changes will affect contractors and consumers alike. The IET wiring regulations are non-statutory, meaning they are not an absolute law. Although if not followed, you can find yourself foul of the EAW (Electricity at work regulations). What new changes will come with the 18th edition wiring regulations? How will they affect you? This is the big question that everyone is asking. There were some big changes last time when metal consumer units were reintroduced. Read on to find out the latest changes that will be coming in on the 1st July 2018. Keep in mind that although this is the latest information available. The 18th edition wiring regulations changes are still at the draft stage being reviewed by the subcommittee. Regulation 722 – The electric vehicle regulations With the world marching further forward, innovations in the electric vehicle sector are pushing the demand for charging stations skyrocketing. What used to be a rare sight is now much more commonplace, electricians are n ow struggling to keep up with this demand. Furthermore, with increased use, the safety element has been re-evaluated and particularly regulation 722.411.4.1 that specifies the use of PME has been changed. The exception for a dwelling if none of (i), (ii), or(iii) is reasonably practicable has been deleted. This now means that PME cannot be used unless you meet (i), or (ii), or (iii) of 722.411.4.1. As a reminder of those regulations: Regulation 722.411.4.1(i) refers to a situation where a connecting point is supplied from a 3-phase installation used to supply loads other than charging points and where the load is sufficiently well balanced.Regulation 722.411.4.1(ii) requires a very low resistance earth electrode to mitigate the effects of an open circuit PEN conductor fault on the supply. Regulation 722.411.4.1(iii) refers to protection by a voltage operated device. An important change is that the regulation now makes the point that this device could be included in the charging equipment. It is worth noting that this device will also require an earth electrode. So effectively this means that installing an electric vehicle charging station will likely require an earth electrode to be installed. The regulations also bring about more requirements in regards to solid foreign body protection IP4X and impact protection AG2. RCD protection Regulation 722.531.2.101 has been redrafted concerning RCD protection. You must now have Type A and Type B RCDs being able to handle DC fault current. Furthermore, where BS1363-2 socket-outlets are used for EV charging, it has to be labeled clearly ‘EV’ on the rear side of the enclosure. Unless there is no possibility of confusion, a suitable label shall be put on the front face or next to the socket-outlet or it’s enclosure stating: ‘suitable for electric vehicle charging’. Additionally, socket-outlets absolutely need to be fit for purpose. Being adequate for the load and any external influences that may hinder its performance during the lifetime of the unit. Such as impact damage or water. Changes to Section 753 Section 753 of the 18th edition wiring regulations changes now include electric floor heating. They also apply to electric heating systems for de-icing or frost prevention or similar applications and cover both indoor and outdoor systems. This can be floor s, walls, and ceilings. Outdoor or indoor. Compacted areas such as roadways or football field, for example,e are covered under section 753. There are now more requirements in relation to covering heating elements in soil or concrete. Wall heating systems are now required to have metal mechanical protection such as sheathing or metallic grid. There are further requirements in relation to being laid near ignitable material. A 10mm air gap is considered to be sufficient. Section 730 – Onshore units of electrical shore connections for inland navigation vessels Existing regulations in regards to marinas will mostly also be applied to inland navigation vessels. Most, if not all, of the measures used to reduce the risks in marinas, apply equally. The main differences being the size of the supply needed. Three phase (400v) is now required. Furthermore, where PME is used no neutral should be connected to metal work of any caravan or boat. Additionally, there are now requirements for use of isolating transformers This is to prevent circulating galvanic currents between vessels and metallic parts of the shore side. Also, minimum protection of IP44 will now apply to equipment that is installed.There are also now further requirements on using suitable cables which will not deteriorate under mechanical and environmental stresses, for distribution circuits in berths and ports and floating land stages. Furthermore, underground distribution cables must be buried at a depth that will avoid damage from such things as vehicle movement. Overhead cables are not allowed to be installed above waterways. If overhead cables are used they must be insulated. Any support for them must also be adequate protection. The conductors must also be at a height of at least 6m in areas where there could be vehicle moment and 3.5m without. Isolation, switching and control (automatic disconnection of supply) RCD protection Section 730 gives additional requirements concerning RCD protection. Particularly the use of RCDs protecting each individual circuit up to 63a. Isolation and over-current protection are also included.Socket outlets in section 730 of the 18th edition wiring regulations changes will now include further requirements (a) Socket-outlets shall comply with BS EN 60309-1 and BS EN 60309-4 and socket-outlets with a current rating up to and including 125 A shall comply with EN 60309-2. (b) Where interchangeability is not required, socket-outlets shall comply with BS EN 60309-1 and BS EN 60309-4 and need not comply with BS EN 60309-2. (c) Sockets need to be as close to the berth are reasonably practical. (d)There should not be more than 4 sockets in one enclosure. (e) Each socket-outlet should only supply one electric circuit of a vessel. (f) Socket-outlets shall be placed at a height of not less than 1 m above the highest water level. (g) In the case of floating pontoons or walkways only, this height may be reduced to 0.3 m above the highest water level provided that appropriate additional measures are taken to protect against the effects of splashing. (h) Socket-outlets shall be placed in an enclosure in accordance with BS EN 15869-2. Conclusion This article only gives an overview of draft proposals, which may or may not be included in the 18th edition (BS 7671:2018), depending on the decision of the national committee, JPEL/64. The DPC (draft for public comment) is now available to the public (on the BSI website) for comment. So that’s the overall changes which will come into effect with the 18th edition wiring regulations changes, although it’s important to keep in the mind that the changes listed are still in draft stage. We will found out on July 1st 2018 the final requirements of the 18th edition wiring regulations. See here for courses to make sure you are up to date. EDB Electrical Services are your local electricians based In West Sussex. __________________________________________________________________________________ Now that you’ve finished reading here, why not check out some of our other content such as: Wylex Fuse board change Local electricians in Littlehampton, West Sussex How much does a new fuse board cost? Social Media Update...
- Case Study – Replacing an old Wylex fuse boardMarch 16, 2018Electrical Case Studies / Latest news & UpdatesThe photograph shown is of a Wylex 3036 re-wireable consumer unit. EDB Electrical Services gave a quote to carry out the task of replacing the consumer unit and carrying out the upgrading of the bonding to the oil and gas supplies. The old consumer unit was replaced with a Hager 6×6 split load 60898 consumer unit as shown. The whole installation was then protected by RCDs and 60898 MCB’s The installation was originally given an EICR which it failed.Now with the new fuseboard the electrical installation passed with flying colours. __________________________________________________________________________________ Now that you’ve finished reading here, why not check out some of our other content such as: Do you need an RCD? Local electricians in Littlehampton, West Sussex Electricians In Shoreham-By-Sea, West Sussex Social Media Update ...

Monthly Archive September 2018

Why are consumer units now made of metal?

Consumer units are now required by the regulations to have the construction of non-combustible materials

So what are the main reasons metal consumer units are required by the BS7671:

Looking at the above, metal seems like a great choice, but of course, with most pros, there are also cons:

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