Upgrading my service from 60Amp to 100Amp

David-S · Mar 17, 2024

My house was built in the 1930s, The fuse in my service cut out is 60Amp and the wire coming from the street has a 16mm2 copper core(easy to see against the 25mm2 copper tails into the smart meter)

I am ready to install a new 10.8kW Shower, Is a simple fuse change sufficient?

Ive been told by an electrician that the 16mm2 cable coming from the street should be 25mm2 to support a 100A fuse.

I have 6 other people in the house, a 4.2kw oven, and 7kw electric car charger.

Its impractical to take turns in using appliances, on certain days the EV charger, oven, and shower could all be in use together, Along with TV, PlayStation, Kettle, etc also being used.

What would you guys advise?

mhar · Mar 17, 2024

Either you or your electrician need to contact your dno to ask about increasing the supply fuse, neither of you are allowed to make this change, only your dno can. In my area you will only get an 80A max and that is if local network demand allows this. Whilst under our regs 16mm tails shouldn't be used for 100A supplies the dnos work to different regs and it is up to the Network Planner to determine whether the cable is sufficiently sized for the demand.
There is a holiday cottage on my street that was running 4 x 9.5kW showers off a 60A fuse for 10-15 years without ever blowing the fuse, they can take considerable short and medium duration overcurrents. All four showers were likely to be used at similatr times as the guests arrive back from the beach, however that does not mean that this is the correct thing to do

Rockingit · Mar 17, 2024

I think you need to upgrade your electrician rather than your absolutely adequate supply.

David-S · Mar 17, 2024

mhar said:
Either you or your electrician need to contact your dno to ask about increasing the supply fuse, neither of you are allowed to make this change, only your dno can. In my area you will only get an 80A max and that is if local network demand allows this. Whilst under our regs 16mm tails shouldn't be used for 100A supplies the dnos work to different regs and it is up to the Network Planner to determine whether the cable is sufficiently sized for the demand.
There is a holiday cottage on my street that was running 4 x 9.5kW showers off a 60A fuse for 10-15 years without ever blowing the fuse, they can take considerable short and medium duration overcurrents. All four showers were likely to be used at similatr times as the guests arrive back from the beach, however that does not mean that this is the correct thing to do

This is my service.

[ElectriciansForums.net] Upgrading my service from 60Amp to 100Amp

Rockingit said:
I think you need to upgrade your electrician rather than your absolutely adequate supply.

Whys that? What is wrong with what he said?

westward10 · Mar 17, 2024

Who took the cover off that?

littlespark · Mar 17, 2024

In other words, that part of the electrical installation should not be accessed by untrained personnel… not even your electrician.

It is dangerous to uncover live parts such as this, as well as an offence.

David-S · Mar 17, 2024

westward10 said:
Who took the cover off that?

littlespark said:
In other words, that part of the electrical installation should not be accessed by untrained personnel… not even your electrician.

It is dangerous to uncover live parts such as this, as well as an offence.

My electrician said there were no ferrule crimps, so makes no odds.

westward10 · Mar 17, 2024

Your electrician doesn't sound overly intelligent or have you taken it off.

littlespark · Mar 17, 2024

We’re just trying to help you out here….

Your electrician isn’t taking diversity into account… that’s where your total load of over 100A won’t take anything near that at any given moment.
Your 60A will be fine, but the DNO could increase to 80 if asked.

What’s the lack of ferrule crimps got to do with it?

That cut out should have never have been opened… and usually, it can’t be without the main fuse being drawn.

westward10 · Mar 17, 2024

I think ferrule crimps refer to cut out seals.

David-S · Mar 17, 2024

littlespark said:
We’re just trying to help you out here….

Your electrician isn’t taking diversity into account… that’s where your total load of over 100A won’t take anything near that at any given moment.
Your 60A will be fine, but the DNO could increase to 80 if asked.

What’s the lack of ferrule crimps got to do with it?

That cut out should have never have been opened… and usually, it can’t be without the main fuse being drawn.

its a cover only, with nothing inside attached.

when you say dno could increase to 80, is that via fuse change?

David-S · Mar 17, 2024

westward10 said:
Your electrician doesn't sound overly intelligent or have you taken it off.

He removed the composite cover no differently than a DNO would have done.

westward10 · Mar 17, 2024

I'm not sure where this thread is going or what you are demonstrating is by an electrician or yourself. It doesn't really matter as the forum cannot condone what has been undertaken, it is dangerous and as such this thread is closed.
Seek the advice of your service provider.