Commercial Consumer Unit & Distribution Board Upgrades in Milton Keynes
Single phase to three phase, MCB to RCBO, fuseboard to modern distribution board. We upgrade commercial consumer units to support EV charging, solar and current safety standards.
When does your business need an upgrade?
- Adding EV chargers — multi-bay car parks usually require additional capacity
- Adding commercial solar — your distribution board needs to handle the inverter feed-in
- Old rewireable fuse board — being phased out, no longer compliant with most insurance
- MCB-only board — needs RCD/RCBO protection to meet current regulations
- Failing EICR — C1 or C2 codes on the distribution board itself
- Expanding premises — new circuits or additional load needed
- Equipment changes — adding three-phase machinery or rapid chargers
Single phase vs three phase
Most small commercial premises run on a single phase supply (same as a home). Larger commercial buildings, factories, and anything with rapid EV chargers or three-phase machinery need a three phase supply.
Signs you may need to upgrade from single to three phase:
- Adding rapid EV chargers (22 kW+)
- Installing three-phase motors, lifts or commercial kitchen equipment
- Existing single-phase supply is at capacity
- Extending premises significantly
Three-phase upgrade requires a DNO application — we handle this for you. Typical lead time 6-8 weeks for the supply upgrade, then we install the new board.
What's included
- Supply and fit of new commercial distribution board
- RCBO protection on every circuit (individual fault protection)
- RCD protection where required
- Full circuit identification and labelling
- Test certificate (EICR and/or EIC depending on scope)
- Building Control notification under Part P
- DNO application service if going three-phase
- 12-month workmanship warranty
RCBO vs MCB+RCD — why we install RCBOs
Older boards use a row of MCBs (Miniature Circuit Breakers) for overcurrent protection plus one or two RCDs (Residual Current Devices) protecting groups of circuits. The problem: when an RCD trips on one fault, it takes out every circuit on that group.
Modern RCBOs combine both functions per circuit. One circuit faults, only that circuit trips — the rest stay live. Better for diagnosis, better for business continuity, and now standard for all new commercial boards.
Capacity for EV and solar
If you're planning to add EV chargers or solar, your existing distribution board often needs upgrading first. We always assess this at survey stage so there are no hidden costs later.
- EV chargers: each 7 kW socket adds significant load; multi-bay sites often need a board upgrade plus a DNO supply increase
- Commercial solar: the inverter needs a dedicated breaker on the AC side, with sufficient capacity for the system size
- Future-proofing: we typically size new boards with 20-30% spare capacity so you can add more circuits later without another upgrade
Pricing
Process
- Survey — we assess your existing board, supply, load profile and future plans
- Design — circuit schedule, board sizing, protection scheme
- Order materials — typically 5-10 working days
- Install — half-day to full day for most commercial swaps; longer for three-phase upgrades
- Test & certify — full electrical test, EIC issued same day
- Building Control notification — handled for you
Quote your commercial board upgrade
Free site survey, fixed price, all DNO and Building Control paperwork included.
Frequently Asked Questions
How long does a commercial consumer unit upgrade take?
Can I add EV chargers to my existing board?
Do I need to upgrade to three phase for commercial solar?
Will my business have to close during the upgrade?
What's the difference between a consumer unit and a distribution board?
Do you handle Building Control notifications?
Ready to get started?
Free no-obligation quotes from your local MCS & NAPIT certified installer in Milton Keynes and Buckinghamshire.