Lake Electrical is a commercial electrical contractor based in Battle, East Sussex, and main intake panels, LV switchgear and power distribution are part of the work we carry out for universities, schools, offices, industrial sites and churches. Here we set out the signs your main switchboard needs replacing, how they usually come to light, and how a replacement is planned so the building can keep running while it happens.
What the main switchboard does
The main switchboard, or main LV distribution panel, is where the incoming supply arrives and is divided up. Every distribution board and every circuit in the building is fed from it.
It is also the one piece of equipment you cannot work on while the building carries on as normal. Replacing it means taking the building off supply, so the job needs careful planning, and starting that conversation early gives you more options.
Your EICR has flagged it
Power distribution upgrades often start with an EICR rather than a planned replacement. The people responsible for a building won’t necessarily know their main panel is near the end of its life until an inspection points it out.
A thorough inspection can pick up problems with the main panel, the distribution boards, the submains, the protective devices, the earthing, or the access you need to isolate safely. If the report comes back unsatisfactory, it means something needs action or further investigation. We explain what has been found and whether it can be repaired, or whether replacement or a wider upgrade should be considered, and we quote for that work separately so you can see the cost before you decide.
Sometimes a panel has a few years left in it. Sometimes it should have been changed a long time ago. Our Chichester university project came about this way. The EICR showed the main intake panel, which dated from the 1950s, was no longer up to standard, and that led to its replacement.
If you want to understand the report codes, our guide to Electrical Installation Condition Reports explains what C1, C2, C3 and FI mean.
There is no spare capacity
If a board has no spare capacity, or the existing distribution cannot support what you want to add, the distribution system may need upgrading.
Taking on more offices, adding EV chargers, electric heating or bringing in new equipment all add load, and EV charging in particular can increase demand significantly. An LED lighting upgrade works the other way and may reduce it. We look at the load the building uses now and what you may need in future.
If the building is getting close to the capacity of the incoming supply, a supply upgrade from the DNO may be needed as well. The DNO has its own application, design and connection process, and its timescales can affect when your project goes ahead.
The distribution has grown piece by piece
Older buildings often have distribution that has been added to over many years. Extra boards get connected as the building grows, loads change and new equipment arrives.
Eventually that leaves you with full boards, distribution nobody can follow, limited capacity, or circuits you cannot isolate without affecting other parts of the building. We design the distribution around what the building needs rather than simply replacing what is already there.
Replacement parts are no longer available
When a main switchboard reaches the end of its life, replacement parts stop being available, capacity runs short and the risk of an unplanned outage goes up.
What replacing a main switchboard involves
We start with a survey and load assessment. We look at the existing installation, the current load and maximum demand, and the capacity you are likely to need in future.
We then design the intake, metering, main panel, LV switchgear, submains and distribution boards around what the building needs, rather than simply replacing what is already there. That includes earthing, main protective bonding and surge protection where required. Panels are specified and tested to BS EN 61439, and the installation is designed, inspected and tested to BS 7671.
A main panel replacement often involves more than electrical work. Walls may need opening, plinths forming, intake rooms altering, firestopping reinstating or access changing to get the new equipment into position. Where that is needed, we manage subcontractors we know as part of the same programme and stay responsible for the electrical design, installation and connections, so you have one team to deal with.
At handover you receive the electrical certification, circuit schedules, test results, updated distribution schedules and record drawings, with every board and circuit clearly labelled.
Keeping the building running during the changeover
Replacing a main switchboard does not have to mean closing the building. We plan the changeover around how the building operates, using temporary supplies, backup generators or moving individual boards in stages. There will usually be some planned isolation, but we agree it with you before work starts and schedule it for the most suitable time.
As main contractor on a university campus, we replaced the main LV switchboards in three separate buildings, a programme worth around £785,000 combined. Each switchboard was replaced in a shutdown of roughly four to six days. Essential circuits were moved onto temporary generator supplies before the old equipment came out, and our engineers worked back-to-back shifts so each building could be handed back as quickly as possible.
At Chichester, we changed a £310,000 main intake panel over three days using backup generators, and the laboratories stayed powered throughout.
Read the LV switchboard replacement case study
Plan the replacement before you need it
If your existing supply has enough capacity, we can plan the work around your own programme. If the supply needs increasing, the DNO becomes part of the process and the timetable partly depends on them.
Either way, starting early gives you more choice. The work can be phased, split across more than one spending period, or the main changeover can be booked for the time that causes least disruption, such as a school holiday or a university vacation. If you already have a holiday period in mind for the work, the survey is the place to start. Where required, we can also manage the DNO application and coordinate it with the rest of the project.
Talk to us about your main switchboard
If you are seeing signs your main switchboard needs replacing, or an EICR has flagged it, we can start with a survey and load assessment and tell you what the building needs. Read more about our main panels and power distribution work, or call the team on 01732 758 985, Monday to Friday, 8am to 5pm.
We are an NICEIC Approved Contractor and SafeContractor accredited, our engineers are DBS checked, and we have been trading since 2008. We carry out power distribution work across Kent, East Sussex, Surrey and the wider South East.