Replacement, certified consumer units
A new consumer unit reduces the risk of electric shock and fire. Older rewireable and minature circuit breaker fuse boards cannot offer this additional protection. Consumer units are the brain of the electrical installation. They protect the cables, occupiers and the building.
Do you need to replace your consumer unit?
Some reasons customers have a new metal distribution board installed:
1. They need a new circuit and their existing fuse board has no spare ways to connect it.
2. They want an electric shower or outdoor socket and have no rcd protection.
3. Fault finding identified a component problem and the replacement part is no longer available.
4. An electrical inspection has advised rewireable fuse boards no longer comply.
5. Loft conversion plans state a new board will be necessary.
The cost to install a new consumer unit depends on the number of circuits and existing wiring. Test results or fault finding may state the existing installation needs upgraded meter tails for example. The problem arriving with a replacement and starting the job is you are banking on no problems. It is for this reason many electricians recommend testing prior to fitting the new one.
If the circuit tests come back OK that’s great news and the job can begin! If they don’t the customer will know what is necessary to resolve the faults, or rebook if time is an issue.
Some examples of how the fixed wiring installation can affect the cost of replacing a consumer unit:
1. If your fuse board is “boxed in”, that may need removing or cutting to allow the replacement enough space. The latest units are metal, heavier, wider and deeper than the previous plastic ones. The hinged door (which needs to remain in place) can add another 100mm of depth. New properties have a lot of plasterboard walls and a secure fixing can be another issue.
2. The existing wiring isn’t long enough. The power supply leaves the electric meter and connects to the the main switch inside the consumer unit. Depending on the make, that is either on the left or right. The meter tails are cut to the required length at the time of original installation. If they aren’t long enough; new ones will be necessary to install your new distribution board.
Some of the wiring from the circuits in your house may need extending to connect to the new circuit protection. This is because different makers have their circuit protection in different layouts. Extending cables adds time to the job.
3. The lighting circuit doesn’t have an earth wire. Most light fittings require an earth connection. If your wiring doesnt have one; metallic fittings and switches aren’t permitted. This is one of the biggest replacement consumer unit show stoppers.
4. The wiring for the socket circuits isn’t complete. The circuit design for socket outlets requires the wiring to be a continuous ring. This fault is common and can mean additional fault finding is necessary.
5. The main bonding cable no longer complies. Gas and metallic water pipes need a connection back to the main earth terminal. If yours is missing or doesn’t test out OK – it will need updating.
6. The neutral and earth wire for the lighting circuit is one. This needs resolving for electrical safety and to enable rcd fitment.
7. The main earth reading is too high. In rural areas the power supply lines enter the property overhead. In these cases you are responsible for your own (safety) earth connection. This is in the form of an earth rod outside the property. If the reading is too high it will need resolving prior to replacing the board.
8. Residual earth leakage. Faulty appliances (and wiring) can allow current to leak. RCDs present in the latest consumer units are designed to trip to protect, older fuse boards don’t. High amounts of residual current needs resolving prior to installing an rcd equipped distribution board.
9. Five circuits turns in to eight. Additional wires are added to the circuit protection since the original installation date. Replacing the consumer unit is an ideal time to resolve this.
10. The location of your electric meter. Some being in a small cupboard under the stairs making access difficult, increasing working time.
On the day your consumer unit’s replaced power for the whole property will be off. Your telephone line will work but your broadband equipment won’t. It isn’t a matter of unscrewing the old one and fitting the new one! I need access to the whole property as some of the tests require checks at socket and light fittings.
Expect to pay between £350 and £500 to have a new consumer unit installed in the Cardiff area. Registered electricians like myself will supply the compliance certificates. This will ensure you don’t have any problems in the event of an insurance claim or if you decide to sell your home.