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Double wound safety transformer for EV supply.

Hi everyone, I have only posted once before so thanks to anyone who replies!

I am following on from the earlier "70 volt PEN conductor not allowed to exceed post", and looking into supplying a client with an electric vehicle power supply from a three phase isolating transformer BS 7671 722.413 (1.2): " The circuit shall be supplied through a fixed isolating transformer.."

The general consensus seems to be that an external IP box with an RCD (Type B) and a tethered lead is the standard to follow, and this may be the only option with a 230 volt domestic supply, but why not use a 3 phase 400 volt step down or tapped, safety double wound isolation transformer in a standard 100 -200 ampere or above industrial units/sheds?

( Subject to load and diversity).

The answer often stated when I have asked sparks/engineers is that in-rush current are too high but a type D CB BS 60898 will 'let through' the in-rush ( the transformer manufacturer agrees), and will still give at 5 seconds- (final circuit exceeding 32 A) 0.44 ohm EL ( 10oC) , so is achievable in many situations local to Birmingham.

I was then going to run a fused cable out to an external isolated IP 65 box with a Type 2 socket to IP44 or above ( 722.55.101).

Isn't it better to engineer a solution to the upcoming electric charger deluge, rather than buying (insert well known manufacturer name here), and lots of single phase loads usually dumped onto L1?

I would be interested in any thoughts or problems you may consider....

Parents

0 SL1 over 5 years ago

mapj1:

Perhaps cars should come with a power of opportunity adapter kit containing a lead ending in two insulated croc clips, some thick gloves, a jemmy bar and a selection of keys for lamp posts and street boxes and so forth, and maybe some wire cutters. The ideal Christmas present for the intrepid EV owner. ?

There is a disconnection in the level of safety we expect for a traditional car where we happily use fuel pumps and jerry cans, when compared to the far higher level we expect for indoor electrics with ADS and all the rest.

?? This will probably happen if it hasn't already.

Perhaps some form of utilisation of the street lighting system could be used in some way?

I wonder if the REC or DNO have got something legitimate in the pipeline for this?

A readily available power supply infrastructure, I wonder if the the power supplied into the columns could be 'beefed up' and separate enclosures with RCD/Charging etc kit added?

Regards

Simon
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0 SL1 over 5 years ago

mapj1:

Perhaps cars should come with a power of opportunity adapter kit containing a lead ending in two insulated croc clips, some thick gloves, a jemmy bar and a selection of keys for lamp posts and street boxes and so forth, and maybe some wire cutters. The ideal Christmas present for the intrepid EV owner. ?

There is a disconnection in the level of safety we expect for a traditional car where we happily use fuel pumps and jerry cans, when compared to the far higher level we expect for indoor electrics with ADS and all the rest.

?? This will probably happen if it hasn't already.

Perhaps some form of utilisation of the street lighting system could be used in some way?

I wonder if the REC or DNO have got something legitimate in the pipeline for this?

A readily available power supply infrastructure, I wonder if the the power supplied into the columns could be 'beefed up' and separate enclosures with RCD/Charging etc kit added?

Regards

Simon
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Double wound safety transformer for EV supply.

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