Distribution Cellar upgrade

we transformed this mess in to.....


this......


unbalance power loads & Phase overload

Years of poor additions have resulted in overloading one of the phases in their main 3 phase supply. Which meant every now and then when this premises ( club house, commercial kitchen & a bar) have a function and operate all their electrics, phase 3 kept blowing its main supply fuse due to unbalanced power loads

we measured their power demands during peak times and discovered

  • Phase 1 operate at 10% capacity

  • Phase 2 operate at 30% capacity

  • Phase 3 operate at 150% capacity

Endless issues with this installation

unbalanced power loads were only part of problem. There were various other issues that had to rectified to bring the installation up to a satisfactory standard. Some of the issues were


  • Lots of exposed basic insulation in most of the conductors

  • incorrectly size supply tails were used to supply power to some distribution board

  • number of consumer units were added on ( as submains) to a one main consumer unit (single phase) and this was wired in to phase 3. Which meant, unlike in a 3 phase (TPN) distribution board, circuits could not be moved between phases to balance power loads

  • Number of old MICC cables with poor cable terminations

  • circuit breakers with thermal damages supplying power to sub fuse boards

  • no glands or grommets for most of the cable entries and exits from fuse boards, which had resulted in sharp metal edges from fuse boards cutting in to sheathing of most of the conductors ( cables were stretched)

  • incorrect size conductor were wired in to bigger circuit breakers

  • wide exposed cable entry holes in most of the fuse boards

  • And the list goes on and on

  • No RCD protection for most of the socket circuits







Issues were endless and we could not see any easy quick fix solution to this

So we decided to strip it all out and start again .......

in the process of dismantling the exiting distribution set up

at this point we had cleared out most of it

New Set up underway

  • We've installed a new Uni-Strut frame structure and installed a approx 25mm thick marine ply board

  • all new distribution gear will be now installed on to this ply

  • We had to get the DNO & MO to re-position electrical meters

  • we've decided to separate "Distribution circuits" and "Final Circuits" in to two separate TPN distribution boards

  • One of the boards ( one of the left) is now supplying power to all submains and number of other heavy power circuits ( such as oven commercial) and solar panel feed in connections etc

  • TPN DB on the right is supplying power to all final circuits located in various parts of the building - mostly socket ring mains ( all circuits RCBO protected)

Testing & Inspection in accordance with BS7671 IET wiring regs

dead testing of all circuits were carried out prior to energising them with new distribution gear, Full range of live testing were carried out afterwards

much neater installation with increased electrical safety to circuits