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Hi all, long time member but not many posts to my name. I would appreciate advice and opinions on a job I have been asked to do for a friend of a friend.
I have been approached to carry out some electrical works at a funeral parlour. They want to convert the upstairs of the building into rentable offices and a small kitchen / welfare area. The upstairs will be completely stripped out, minor layout changes, new ceilings and re-plastered walls. The electrical works will include 2 x ring final circuits, 2 x lighting circuits and a water heater supply. As usual, the client is looking for the cheapest and least disruptive solution.
I have surveyed the existing electrical installation in the building and have found the following:
Incoming TP&N 80A supply, TN-S. Bonding in place to water and gas.
The building has been re-wired in PVC T&E, I would estimate around 15 – 20 years ago but the wiring and accessories appear to be in good condition.
DB 1 – TP&N Wylex, part insulated with 3871 MCB`s. This provides general lighting and power for the whole building. 10 MCB`s in use. I would estimate the total loading of less than 20A across the 3 phases as they only have a small office area, display room, chapel of rest, meeting room and a small kitchen. Only 1 person works in the building at present.
DB2 – TP&N Wylex, part insulated with 3871 MCB`s. This is live but not in use as it used to be an off peak DB, providing power for storage heaters in each room. Gas central heating is now installed so this board is redundant as are the 11 radial heater circuits.
Now for my question, as the new circuits will require RCD protection, I have 3 options:
1 – Replace existing DB1 and provide RCBO`s for existing and new circuits (expensive but probably the best option)
2 – 60A SP&N Sub-main to upstairs in 3 core 10mm SWA and new SP&N consumer unit with dual RCD and MCB`s and leave existing DB1 as it is. (cheapest option)
3 – 60A SP&N Sub-main to new consumer unit upstairs and also replace existing DB1 with a SP&N dual RCD consumer unit. (This will leave phase L3 redundant)
I would welcome any advice and opinions on my options for this work
I have been approached to carry out some electrical works at a funeral parlour. They want to convert the upstairs of the building into rentable offices and a small kitchen / welfare area. The upstairs will be completely stripped out, minor layout changes, new ceilings and re-plastered walls. The electrical works will include 2 x ring final circuits, 2 x lighting circuits and a water heater supply. As usual, the client is looking for the cheapest and least disruptive solution.
I have surveyed the existing electrical installation in the building and have found the following:
Incoming TP&N 80A supply, TN-S. Bonding in place to water and gas.
The building has been re-wired in PVC T&E, I would estimate around 15 – 20 years ago but the wiring and accessories appear to be in good condition.
DB 1 – TP&N Wylex, part insulated with 3871 MCB`s. This provides general lighting and power for the whole building. 10 MCB`s in use. I would estimate the total loading of less than 20A across the 3 phases as they only have a small office area, display room, chapel of rest, meeting room and a small kitchen. Only 1 person works in the building at present.
DB2 – TP&N Wylex, part insulated with 3871 MCB`s. This is live but not in use as it used to be an off peak DB, providing power for storage heaters in each room. Gas central heating is now installed so this board is redundant as are the 11 radial heater circuits.
Now for my question, as the new circuits will require RCD protection, I have 3 options:
1 – Replace existing DB1 and provide RCBO`s for existing and new circuits (expensive but probably the best option)
2 – 60A SP&N Sub-main to upstairs in 3 core 10mm SWA and new SP&N consumer unit with dual RCD and MCB`s and leave existing DB1 as it is. (cheapest option)
3 – 60A SP&N Sub-main to new consumer unit upstairs and also replace existing DB1 with a SP&N dual RCD consumer unit. (This will leave phase L3 redundant)
I would welcome any advice and opinions on my options for this work
