Can no longer have an 80amp supply?!

[phatboy]

I am in Jersey, where our only DNO & Supplier is Jersey Electricity.

In my previous house we had storage heaters fitted, and the supply was changed from 60amp to 80amp - no problem.

Now we have moved house and fitted storage heaters again. I filled out the form to request an upgrade and this was approved, for 100amp. I asked if we could have 80amp as this was sufficient, but they apparently no longer offer this, just 60amp and 100amp.

I will need to upgrade as with the heating, lights and 1 oven on we are at 55amp, but this will mean new 25mm tails to both CU's, so I will have to have an electrician attend at the same time as the meter people to complete the upgrade. They may also require the earth bonding to be changed from 10mm to 16mm.

I appreciate nobody here can say for sure probably why an 80amp supply has been discontinued by my supplier/DNO, but maybe someone can hypothesise as to why?

Surely me requiring less power leaves more available for other customers in the area? In fact I know it would, as a neighbour requested the same upgrade later than me, and was told they would need 3-phase!

Sorry for the lengthy post.....

Thanks
Tim

 

[333rocky333]

Reminds me of a pub, that when trading the kitchen overloaded and blew one of the 3 60 amp supply fuses,each time bypassing the 3phase switchfuse as it was rewirable 60 amp fusewire.
The incoming supply cable looked so small id guess no more that imperial version of 4mm.
The Leb as it was called then just came in and stuck 100 amp carriers on with 100 amp fuses, they didnt even comment on anything else.
This ran like that for about ten years before it was bulldozed for flats.

 

[Doggit]

I'm sure an electrician will give a more qualified answer, but you getting a larger supply doesn't mean that there's less for others, it just means that there's more spare capacity should you need it. You'll only get charged for the amount of electricity you use, not for the amount it can supply.

 

[JohnW2]

...I filled out the form to request an upgrade and this was approved, for 100amp. I asked if we could have 80amp as this was sufficient, but they apparently no longer offer this, just 60amp and 100amp. ... I appreciate nobody here can say for sure probably why an 80amp supply has been discontinued by my supplier/DNO, but maybe someone can hypothesise as to why? .... Surely me requiring less power leaves more available for other customers in the area?

Are you just talking about the rating of the fuse in their cutout, or will they have to upgrade their cables to give you more than 60A?

As you say, no-one can tell you why they've decided not to offer 80A. However, if we're just talking about their fuse, then I don't think it really makes much difference (for them - as you say, you might need fatter meter tails and/or bonding conductors). Don't forget that when working out what is available for supplies to other properties, their "after-diversity (time-averaged) estimate" of your house's consumption will probably not be much more than about 10A (Edit: Oh, maybe 20A or so given your storage heaters, which I had overlooked) - whether your cutout fuse is 60A, 80A, 100A or whatever!!

Kind Regards, John

 

[EFLImpudence]

Why can't you fit an 80A switch-fuse instead of changing the tails?

It'll be handy as an isolator, anyway.

 

[phatboy]

Why can't you fit an 80A switch-fuse instead of changing the tails?

It'll be handy as an isolator, anyway.

True, but the cost of the electrician for 1hr minimum probably cancels out the cost of the switch-fuse! And I would need one for peak, and one for off peak?

 

[Iggifer]

WPD no longer offer a 100A new supply 'round these parts, they may upgrade existing to 100A in some circumstances but all the new supplies we've been involved in recently the most they've been willing to put in is 80A. We did some student flats with 5 x 3P&N supplies, some of the flats had 4 electric showers and they were just 80A.

We're negotiating (well, my boss is) for them to install 9 new supplies for some flats and they're complaining he's asked for 60A per flat - I suspect the supply cable in the street isn't up to that much extra demand. They want to give 10A per flat, which is what I suspect they work to generally, but I can't see them putting a 20A fuse per flat in the Lucy. 2 of the flats will have air source so that's getting on for half of the 60A straight away.

It's a mysterious world that of a a DNO.

 

[ban-all-sheds]

This has reminded me, sadly, of Westie, RIP.

 

[EFLImpudence]

True, but the cost of the electrician for 1hr minimum probably cancels out the cost of the switch-fuse!

Hardly. You'll either need both or neither.

And I would need one for peak, and one for off peak?

No.

 

[JohnW2]

No.

Why not?

Kind Regards, John

 

[EFLImpudence]

Why?

He only wants a total of 80A.

 

[JohnW2]

Why? He only wants a total of 80A.

Ah - are you perhaps assuming that he has a tarrif which switches everything over to cheap rate at night, hence just a single pair of tails from meter?

That's certainly now the normal/common E7 situation in mainland UK, but since he asked whether he would need switch-fuses "for both peak and off-peak" I assumed that (per older UK systems) he presumably has two sets of 'tails' (the second set either from the meter or a contactor) - and if he wants all those tails to be BS7671-compliant, he would need to fuse down to 80A separately for both sets if he was not upgrading them to 25mm².

Kind Regards, John

 

[ban-all-sheds]

The NSH tails only need fault protection because of the nature of the load.

 

[JohnW2]

The NSH tails only need fault protection because of the nature of the load.

I had expected EFLI to say that, since it's one of his pet subjects.

Don't storage heaters often have fans, with motors? ... and, in any event, would the cutout fuse necessarily provide adequate fault protection?

Kind Regards, John

 

[EFLImpudence]

Ah - are you perhaps assuming that he has a tarrif which switches everything over to cheap rate at night, hence just a single pair of tails from meter?That's certainly now the normal/common E7 situation in mainland UK,

I am. I thought that was all they fitted now.

but since he asked whether he would need switch-fuses "for both peak and off-peak"

I think he was referring to both CUs.