Been to price a job for a customer, converting an outbuilding to a flat for his daughter. There is an existing house where the mother lives, large dormer bungalow, a garage block, stable block converted into another flat, lived in by the brother, the customer lives in a bungalow at the bottom of the garden and this building to be converted lies beyond that.
The supply is 100amp TNCS single phase feeding all this.
I have expressed my concerns to the customer but the cabling is more of an issue
Isolators are fitted at house and garage but no fuses or mcbs so all the submains are protected only by the cutout fuse
the current layout is this
House consumer unit
6mm SWA approx 20 metres
Garage (the submains are joined before the garage consumer unit though)
6mm SWA approx another 10 metres to stable/house
6mm SWA another 75 metres to bungalow
Bungalow consumer unit
6mm t and e to outbuilding which is to become a flat, currently supplying a hot tub and 2 storage heaters at the moment.
The customer does admit if you put the microwave and the kettle on together, they lights dim and the microwave slows right down
I think a few things are going to have to change as with the proposed work, that will mean 4 electric cookers off the one supply, plus the hot tub, there’s also a garden office building (has its own feed from the meter box) but I’d already say this supply is overloaded.
At least a new supply is needed, three phase ideally or at least another single phase supply to take some of the load off the main one.
There is no way the volt drop can be within limits so I think running new submains down to the new flat and the bungalow are going to be the only option as I certainly don’t want to add anything else to this.
The submains also need some form of over current protection, I’d hate to accidentally find that 6mm swa and go through it with only the cutout fuse as backup
There is of course also the issue of the PME earth being exported, the bungalow and flat are nearly 100metres from where the supply is, and there are no rods or anything, much of the work was done here by the family so although a lot of it appears okay, there are some serious fundamentals that have been missed
I think I may be busy for a while!
The supply is 100amp TNCS single phase feeding all this.
I have expressed my concerns to the customer but the cabling is more of an issue
Isolators are fitted at house and garage but no fuses or mcbs so all the submains are protected only by the cutout fuse
the current layout is this
House consumer unit
6mm SWA approx 20 metres
Garage (the submains are joined before the garage consumer unit though)
6mm SWA approx another 10 metres to stable/house
6mm SWA another 75 metres to bungalow
Bungalow consumer unit
6mm t and e to outbuilding which is to become a flat, currently supplying a hot tub and 2 storage heaters at the moment.
The customer does admit if you put the microwave and the kettle on together, they lights dim and the microwave slows right down
I think a few things are going to have to change as with the proposed work, that will mean 4 electric cookers off the one supply, plus the hot tub, there’s also a garden office building (has its own feed from the meter box) but I’d already say this supply is overloaded.
At least a new supply is needed, three phase ideally or at least another single phase supply to take some of the load off the main one.
There is no way the volt drop can be within limits so I think running new submains down to the new flat and the bungalow are going to be the only option as I certainly don’t want to add anything else to this.
The submains also need some form of over current protection, I’d hate to accidentally find that 6mm swa and go through it with only the cutout fuse as backup
There is of course also the issue of the PME earth being exported, the bungalow and flat are nearly 100metres from where the supply is, and there are no rods or anything, much of the work was done here by the family so although a lot of it appears okay, there are some serious fundamentals that have been missed
I think I may be busy for a while!
