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Discussion Starter · #1 ·
I'm hoping during next week that I'll have 3-phase up and running in my house. We now have two EVs so the ability to charge two overnight is nice to have. I'm pondering on the best approach. I have a single 7kW EO Mini at present so one option would be to simply get another one and wire it up to its own phase. So, I'd have the house on one phase and then the two chargers each on its own phase. However, I could replace the EO with a dual head 3-phase unit which would enable faster charging (theoretically 22kW, but neither can will go past 11kW) and probably a neater install.

Does anyone have any thoughts/input?
 

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If you are replacing your exisiting CU, I would:
  • Install a TP DB from the TP supply.
  • Install 1 new 22kw evcp on a TP MCB
  • Retain exisiting 7kw EVCP and install on L2 or L3 phase (EVs charging on SP through a TP point will charge through L1).
  • Make sure both EVCPs have ALM.
  • Balance exisiting house loads accordingly afterwards, leaving spare ways on the same way that you have had your 7kw charger installed in case of future expansion (i.e. leave 2L1 and 2L2 spare if 7kw is on 2L3).
If keeping exisiting CU, install a smaller TP DB and SP 63A supply from new DB to exisiting CU.. bare in mind you will have less wiggle room for an additional future 22kw if needbe..

I feel 22kw is currently a bit overkill at home.. but on the other hand you are future proofing yourself and giving yourself more options..
 

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OR if you have 2 eligible EVs, have only claimed 1 EVHS grant and dont currently have a massive need for TP changing then just get an additional 7kw unit and install a 5core in case you want to upgrade in the future. That way you can claim an additional grant (you cant claim for 22kw on EVHS).

To note.. defiantly do not change out the exisitng evcp if it is less then 3yrs old and still under warranty..
 

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Discussion Starter · #4 ·
Thanks for the responses. Having seen the cost of the CTEK twin units (£2k!), think I'll just install another 7kW point! Putting 5-core in makes sense for future proofing.
 

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Viridian do 3-phase EVSEs, also they have load-balancing tech for running 2 EVSEs off one limited supply. May be worth asking what thay have? ecoharmony.co.uk also they're posting in here about new products of theirs.
 

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In principle (as long as it uses a sensible open PEN fault protection methodology) the only real difference between a single phase charge point and a three phase one is that it has an extra two poles on the contactor. Everything else is exactly the same. I could turn my charge point from single phase to three phase in about ten minutes, by swapping out the 2 pole main contactor for a 4 pole one. The cost would be around £20 to £25.

In theory, any charge point that's modular (and of decent quality) could possibly be made into a three phase one by retrofitting a replacement contactor. Any charge point that uses a DIN rail mounted contactor, and as long as there's enough space left on the rail it could just have it swapped over. Might need to open out the gland holes and fit new glands, as 5 core cable's a bit fatter, plus the charging cable would need to be swapped over if it's a tethered unit, but that shouldn't be a big job.

IIRC, all Tesla charge points, whether the TWC or UMC, are three phase capable, and the TWC has load management. They work just fine with non-Teslas, and aren't that expensive, either, especially as they use a pretty good quality cable. I think the only snag may be that you may need a Tesla account to buy one, but they do come up for sale on places like ebay from time to time.
 
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