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Nuttyoak

Hi all, after some advise please.

I work as a maintenance engineer at a school and recently we had an outside contractor come in and fit an external Rolec EV unit to the outside of our workshop under the grant scheme.

I don't know much about the installation of these units but I did do part P several years ago so I have some electrical understanding. Consequently I do have some concerns about the installation which may be an issue or maybe more likely just my lack of knowledge!

The EV unit has the internal RCD for the AC supply, and the seperate RCD module for any DC injected back into the circuit. It has been installed with an internal isolator, meter and comms box which all seems fine.

However,

1) The contractors installed a new circuit in our DB for the EV supply but there is no test certificate to show results.

2) The unit is installed in our yard where we store gas cylinders and fuel. The charging unit has been installed directly above a metal storage unit that contains gerry cans of petrol. Gas cylinders are housed in a cage about 2 meters away.

3) The earth from the EV unit has been connected to the building's steel rainwater downpipe which goes under the ground but I've no idea how deep the pipe goes.

Are these issues cause for concern?

I'd appreciate your thoughts.

Many thanks.
 

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Regarding the earthing, it's been connected to the Lightning Protection which isn't ideal but if it's working properly it'll have an overall resistance to earth of less than 10 ohms. I presume you do have the LP system maintained?
 
Regarding the earthing, it's been connected to the Lightning Protection which isn't ideal but if it's working properly it'll have an overall resistance to earth of less than 10 ohms. I presume you do have the LP system maintained?

Yeah, the LP system is maintained by a specialist contractor.
 
Yeah, the LP system is maintained by a specialist contractor.
Can't see an issue with the earthing then unless someone else knows something I don't

Complete side note the way they've drilled the RWP to bond it is something I've only seen a couple of times... Very lazy!
 
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2) The unit is installed in our yard where we store gas cylinders and fuel. The charging unit has been installed directly above a metal storage unit that contains gerry cans of petrol. Gas cylinders are housed in a cage about 2 meters away.
Surely someone from the school would have chosen the location for the charger.
 
Hi - hopefully whoever has engaged the Electrician has the Electrical Installation Certificate. It’d be interesting to see the loop impedance :) .
 
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Hi - hopefully whoever has engaged the Electrician has the Electrical Installation Certificate. It’d be interesting to see the loop impedance :) .

You would think so, but at my place new circuits have been installed to supply some AC units in apartments, not a sniff of an EIC and we won't mention compliance certificates.

Edit By the by @Nuttyoak what supply do you have?
 
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Surely someone from the school would have chosen the location for the charger.

Yeah, the bursar.
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You would think so, but at my place new circuits have been installed to supply some AC units in apartments, not a sniff of an EIC and we won't mention compliance certificates.

Edit By the by @Nuttyoak what supply do you have?

The DB is 3 phrase which is run from the switch gear in the main plant room. The earth is also run from the plant room but I do not know what the earthing arrangement is at the incoming source. I do know we don't have our own sub station which is something we are apparently looking at because the site is so large in both the area it covers and the demand required. We've had issues with volt drop at the furthest corners of the school.
 
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1 Yes an electrical installation certificate should have been completed and issued to the person ordering the work.

2 personally I think that is a daft place to install it and if I had been doing the job would definately have questioned the location. Whilst it should be absolutely fine and is unlikely to be a problem I would err on the side of caution.

3 it's not right, the lightning protection system should be bonded to the Electrical Installation at the main earth terminal and that bond should be connected underground at one of the earth rods. The odd connection they have made could cause a lightning strike to partially divert via the EV charger circuit.
If the LPS is correctly bonded then it will act as a very good earth electrode for the installation sufficient to allow even a PME earth to be used for the charger.

I suspect the installers take a one size fits all, monkey see - monkey do, approach to these installations without applying any thought to the job.
 
The odd connection they have made could cause a lightning strike to partially divert via the EV charger circuit.

And then into the car plugged into it....
We all know what happens when lightning hits a Delorian! 1985 here we come.
Great Scott, Marty!
 
I'd personally move the fuel bin. Doesn't seem ideal to have it where it is.
 
I don't know the ins and outs of LPS which are essentially a stand alone safety system aside from the recent requirement for it to have a main protective bond to reduce pass over in the event of a fault, the chances of the original specification to allow it to be used for another purpose are all but zero.
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Do you have a 12 monthly test of the LPS.
 
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I don't know the ins and outs of LPS which are essentially a stand alone safety system aside from the recent requirement for it to have a main protective bond to reduce pass over in the event of a fault, the chances of the original specification to allow it to be used for another purpose are all but zero.
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Do you have a 12 monthly test of the LPS.

Yeah, we do.
 
That's great be interesting to see what they make of this ad hoc connection.
 
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That's great be interesting to see what they make of this ad hoc connection.
I do this all day every day and I wouldn't say anything about it - if I saw this during an inspection I'd just assume it was a bond to the electrical earth as would my colleagues
 
I do this all day every day and I wouldn't say anything about it - if I saw this during an inspection I'd just assume it was a bond to the electrical earth as would my colleagues
That could well be a natural assumption, do you never verify this. Would this not be deemed an important part of the inspection??
 
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Do you have a 12 monthly test of the LPS.

Our LPS is required to be tested on an 11 monthly cycle to keep track of any season variations.
Ive never known if this is normal or a peculiarity of our storage license.
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I do this all day every day and I wouldn't say anything about it - if I saw this during an inspection I'd just assume it was a bond to the electrical earth as would my colleagues

But it appears to be undersized for the size of the installation and its above ground when it should be below ground level at an earth rod termination.
 
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That could well be a natural assumption, do you never verify this.
We don't have enough time really, some days I have 5+ inspections to do and if something isn't going to affect the LPS I can't justify investigating further

My view is that it's down to the electrician who made the connection to determine whether it's safe or not
 
It is a requirement of the E&WR 1989 I believe.
 
We don't have enough time really, some days I have 5+ inspections to do and if something isn't going to affect the LPS I can't justify investigating further

My view is that it's down to the electrician who made the connection to determine whether it's safe or not

How can you thoroughly inspect 5 sites in a day?
How do you know if it isn't going to affect the LPS if you don't investigate?
 
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Rolec EV installation
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