Cable size

[pennychew]

yeah it looks obvious they have through crimped it to double insulated.

they should have used heat/cold shrink

I'd never heard of cold shrink shanky, looks a good idea

 

[shanky887614]

I'd never heard of cold shrink shanky, looks a good idea

hellerman sleeves are cold shrink, its usually not adesive though and relies on compression to stay on but lasts longer and looks better than tape (adesive heatshrink is best through)

www.wikipedia.org/wiki/Cold_shrink_tubing

 

[pennychew]

Exactly the page I was just reading! Can't beat Wikipedia

 

[DPG]

Why would they have ID'd two of the cables as silver right at the point where the SWA cores join onto the tails? its obviously covering over a through crimp on what looks like 2 different sized cables

Doh. That'll teach me to look properly. Apologies. Daz

 

[lanced]

i might be looking at this wrong but looking at amendment 2 i thought the reason a evcp should not be connected to a pme system was to prevent back feed from the battery if a fault occurred.

722.1
(ii) protection for safety when feeding back electricity from an electric vehicle into a private or public supply network

and says
722.312.2.1
for tn systems the final circuit supplying a charging point for electric vehicles shall not include a pen conductor

so would it not be easier to use 3 core swa, amour earthed at db but not at evcp and use a tt system for the charging point than trying to meet 722.411.4.1 (i) or (ii) or (iii)

 

[uksparks]

Well I called the NICEIC today and they said do not put an earth rod in and just take the SWA out the building and make it part of the TN-C-S installation.

I explained everything in full and explained the proximity to the building etc and that the building it metal and so on.

They even emailed me to confirm as I asked them, they said its fine, they said that in reality its never ever going to be a problem.

 

[telectrix]

so god has spoken, but god is not legally liable if the sh!t hits the fan. good old nicyuk

 

[spark 68]

Probably they are thinking on the lines of Archy's suggestion, if the buildings phases are reasonably balanced, exemption i)

 

[davesparks]

i might be looking at this wrong but looking at amendment 2 i thought the reason a evcp should not be connected to a pme system was to prevent back feed from the battery if a fault occurred.

722.1
(ii) protection for safety when feeding back electricity from an electric vehicle into a private or public supply network

and says
722.312.2.1
for tn systems the final circuit supplying a charging point for electric vehicles shall not include a pen conductor

so would it not be easier to use 3 core swa, amour earthed at db but not at evcp and use a tt system for the charging point than trying to meet 722.411.4.1 (i) or (ii) or (iii)

722.312.2.1 is irrelevant as the final circuit won't include a PEN conductor

 

[uksparks]

Probably they are thinking on the lines of Archy's suggestion, if the buildings phases are reasonably balanced, exemption i)

They said the three phase part for section (i) and also the fact that its a steel building with the steel bonded, he said thats more than likely better than any rod you will put in.

 

[davesparks]

Well I called the NICEIC today and they said do not put an earth rod in and just take the SWA out the building and make it part of the TN-C-S installation.

I explained everything in full and explained the proximity to the building etc and that the building it metal and so on.

They even emailed me to confirm as I asked them, they said its fine, they said that in reality its never ever going to be a problem.

So, will the judge accept 'the NIC said it's ok' in preference to 'I followed bs7671 to the letter' ?

 

[ImpededLoop]

and also the fact that its a steel building with the steel bonded, he said thats more than likely better than any rod you will put in.

For once it sounds like a common sense outcome.

 

[spark 68]

so would it not be easier to use 3 core swa, amour earthed at db but not at evcp and use a tt system for the charging point than trying to meet 722.411.4.1 (i) or (ii) or (iii)

The problem here was the proximity of the PME bonded metal clad building to the TTd ECV, you would be able to touch both Earthing systems simultaneously, which is a shock hazard due to true Earth of the TT part relative to the PME part which may not be at true earth potential at any given time.

 

[davesparks]

They said the three phase part for section (i) and also the fact that its a steel building with the steel bonded, he said thats more than likely better than any rod you will put in.

More than likely better? That's a very precise and technical response!

Once you've tested the effectiveness of the steel structure as an earth then you will be better informed about this. Then with test results to prove it you could make the informed decision that this is safe to do.

 

[uksparks]

More than likely better? That's a very precise and technical response!

Once you've tested the effectiveness of the steel structure as an earth then you will be better informed about this. Then with test results to prove it you could make the informed decision that this is safe to do.

What would the best bethod be to achieve this on this type of buliding?

 

[spark 68]

First off I would be looking at the formula in the annexe associated with exemption i), then clamping the individual tails to see how balanced the building actually is when it is normally loaded, and adding up any further loads from the DB to see if it is possible to severely unbalance it, this would be my starting point.

I hinted at this last night when I said "Archies suggestion is looking better by the minute"

 

[davesparks]

First off I would be looking at the formula in the annexe associated with exemption i), then clamping the individual tails to see how balanced the building actually is when it is normally loaded, and adding up any further loads from the DB to see if it is possible to severely unbalance it, this would be my starting point.

I hinted at this last night when I said "Archies suggestion is looking better by the minute"

He's adding a 60A single phase load to the system, so unless the system is 60A out of balance then the system will be thrown out of balance when the charger is in use.

Clamping it will only give a brief snapshot of the loading, a couple of weeks load study would really be needed to establish a proper idea of what the loading is like.

 

[spark 68]

He's adding a 60A single phase load to the system, so unless the system is 60A out of balance then the system will be thrown out of balance when the charger is in use.

Clamping it will only give a brief snapshot of the loading, a couple of weeks load study would really be needed to establish a proper idea of what the loading is like.

I thought he was fitting a 3 phase charger ?

Agree that longer term monitoring would be a better bet, but if it is outside of the parameters of exemption I) to begin with then he is going to have to load balance it better to start with no?

 

[Simlec]

More to the point has anyone got an electric car to need the charger?
by the time you get it working we will all be in spaceships :driving::driving::driving:

 

[uksparks]

Yes they have two cars already that both draw 16A so that's 32A straight off.

I think without looking at my notes it was 8A on L1, about 30A on L2 and 8A on L3

I am going to put this on L1.

Im not being funny but nobody is ever going to monitor this for even a day let alone two weeks.