Upgrade MIC from 12kVA to 16kVA

unkel

Hi, apologies if this was answered recently, can't find it.

House from 2000, tails are 16mm2, ESB fuse in meterbox is 80A, my fuse in my consumer unit is 63A. A standard 12kVA MIC

Family of 5. Already have 2 EVs, large solar PV and solar thermal setup, large home storage battery. Prefer to heat water in my 360l cylinder with electric and when my 11 year old high efficiency condensing boiler goes, I want to go heat pump, most likely air to air.

Have a smart meter with 3 hour cheap night slot. Can only just about get enough electricity in that 3 hour slot to do me for the day. My bottleneck is clearly my 12kVA connection, want to upgrade at some point to 16kVA, but ESB charge €2068 for this last time I looked. My electrician says 16mm2 tails is good for 80A, but this guideline from the ESB would suggest they want 25mm2 tails?

So they would have to bring a 25mm2 cable into my ESB box from whatever transformer / distribution point in my estate? And on my end, I would have to replace my consumer unit to get a 80A home fuse and use 25mm2 cable whereever I now have 16mm2 cable?

Do I understand all of this correctly?

10-10-20

Just asking whether you pulled that chart off an Irish publication (such as the SAFE Electric PDF) or could that be a UK table?

tomhammer..

It's usually 25 when i was doing 16kva anyhow

Earthing will need upsizing and main board will need upgrading (to probably 80amp )

tomhammer..

https://www.boards.ie/discussion/comment/121879373#Comment_121879373

That's an Irish chart

They're standard supplies here

unkel

https://www.boards.ie/discussion/comment/121879373#Comment_121879373

It's from the ESB.

unkel

https://www.boards.ie/discussion/comment/121879492#Comment_121879492

Yes I was expecting to have to completely replace my consumer unit. It owes me nothing after 24 years and it is full now. I guess there is no other option then to fork out the €2k to the ESB if I want an upgrade of my MIC. Or sit tight and hope the cost will come down

In the transition to renewables, the government would do well to encourage people to switch off their gas supply and start using more electricity. Imho in that light, the former should attract a disconnection bonus and upgrading your MIC should be free.

tomhammer..

https://www.boards.ie/discussion/comment/121879690#Comment_121879690

Safe electric I'd assume not ESBN

tomhammer..

Yes a supply upgrade is both sides

The ESBN side and the consumer side

There's a lot of people now enquiring about ESBN fuses and isolators basically trying to up the capacity without spending on the work needed

It's not a very satisfactory situation now with car charging at the cabinet and DIY supply upgrades

Lenar3556

https://www.boards.ie/discussion/comment/121879698#Comment_121879698

Do you really need to spend €2k to upgrade the MIC? I don’t think they penalise exceeding MIC on domestic connections?

If there is an 80A fuse in the cutout, that’s plenty for 16kva. So unless the 25/16 supply cable is terribly long, there shouldn’t be any issue.

The above may not be strictly correct, but I would be upgrading my board and spend the €2k on something else.

tomhammer..

Those rules on cable sizing don't apply to ESBN

They will likely be using less than 25 , not sure

And the board upgrade is replacement as the boards have a rating. Ya can't just upsize the main mcb

unkel

I don't mind spending money on getting my consumer unit completely replaced with a brand new one. Ideally I would not spend money on the ESB just flicking a button on a computer and coming over for the 10s job of replacing their 80A fuse for a 100A one 😂

So how can I - fully legally and fully safely - get away with drawing closer to 80A from my current MIC?

meercat

You’ll require 25mm from your meter to distribution board

you’ll also require a new earth rod with 16mm cable

some upgrade works will be required in your meter cabinet (Ocpd)

some upgrade work also required on your distribution board (d.p main switch, surge protection)

you’ll also require the house to be tested and certified

depending on your installation,you may require ductwork and open groundwork

all of the above is an additional cost the the esbn service upgrade costs.

tomhammer..

https://www.boards.ie/discussion/comment/121880025#Comment_121880025

To upgrade from 12 to 16 involves ESBN and the REC

Of course there's loads of posters trying to workaround this by maxing out the 80amp esbn fuse and merely upgrading their main mcb and doing little else

tomhammer..

https://www.boards.ie/discussion/comment/121880025#Comment_121880025

You can simply max out your existing system and hope for the best that nothing blows or goes on fire

Sure there's nothing stopping anyone doing that and doesn't require any work

Not advocating the above btw

Lenar3556

On reflection I should say that any proposed upgrade needs to be carefully considered and carried out in such a way that it is safe.

I suppose the point I was making is that there is often very little practical difference between a 12kva and 16kva supply on the networks side and I would have a certain resentment in giving them €2000 for very little. My own house is a ‘16KVA’ supply and has the same 16/25Cu/Al concentric service cable and 100A Henley cut out as if it was a 12KVA. I presume there is a 80A fuse in the cutout.

80A would be on the upper end of safe to carry on the current 16mm Twin and Earth cable supplying your consumer unit. And certainly the consumer unit itself would need to be upgraded (replaced) if you were planning to import more than 60A for any material period of time.

Another consideration is that up until now, ESBN had no way of knowing if you exceeded your MIC other than possibly blown service fuses. With the introduction of smart meters if may well be identifiable.

Lenar3556

https://www.boards.ie/discussion/2058340166/upgrade-mic-from-12kva-to-16kva

Incidentally how do you know the ESBN fuse is 80A?

tomhammer..

https://www.boards.ie/discussion/comment/121881348#Comment_121881348

You're generally getting into risky territory attempting to upgrade on the consumer side only

There's a lot of considerations, voltage drop to main board, CCC of tails ,risk of overheating in cabinet or blowing a fuse

ESBN fuses are standardised presumably, see chart above although no way of seeing obviously

Any rural install I ever did 16kva was specified whether they needed the capacity or not

Reason being they would always bring MV to site and supply from a trafo

They wouldn't attempt to use the overhead LV which could be unreliable but within tolerances which are too large

unkel

Thanks for all the comments and info lads. I have decided for the moment to .... do nothing.

My gas boiler is still working, no urgent need to replace it. And for all the rest, I can cope with my current 12kVA connection and my 3 hour cheap night rate slot. Chances are there will be other smart plans when renewal time comes, that might give 4 hours or more. In fact there is already at least one on the market.

And in a few years from now when we finally catch up with more modern countries, there will likely be variable rates that you can opt into. Can't wait for that, my utility provider will from then on pay me rather than me paying them 🙃

SD_DRACULA

Upgrading the CU inside the house soon and trying to do a bit of future proofing (if ever going for 16kva MIC)

I have already applied for the quote for the 16kva upgrade, the ESBN technician called out and inspected the ESB meter box and said that they cannot advise on the changing the tails from 16sq to 25sq (as that doc specifies above)

They essentially just swap the fuse to 100a and call it a day. There is apparently a 200-300 euro charge for a "rewire" (if needed) where they just change the short cables between the incomer and meter and between meter and isolator.

Question for the folk that went for this upgrade, I assume you all went for 25sq tails but did you also do this part with the "rewire" https://www.esbnetworks.ie/services/existing-connections/rewiring-service

meercat

https://www.boards.ie/discussion/comment/123396906#Comment_123396906

if you are upgrading to 16kva then it’s a requirement to have 25mm tails and also 16mm to the earth rod.
this is the consumers responsibility (work undertaken by a rec)

And you will have to provide esbn with a certificate before they will upgrade.
All this is at your costs.