Cable size

[uksparks]

Care to explain how being a three phase supply removes the need for a rod?

Sorry I meant to add, if it was a dwelling....

 

[uksparks]

the Charge point which is all metal, is 2ft from the all metal outer skin of the building, so can both be touched together.

Ill be honest, I haven't got a clue if it needs one or not reading the regs. I know which id rather rely on, but which is the correct way? Ill admit defeat on knowing, I really do not know.

 

[uksparks]

Except where (i), (ii) or (iii) below applies, a PME earthing facility must not be used where the electric vehicle charging point is located outdoors or where it might reasonably be expected to be used to charge an electric vehicle located outdoors.


An exemption is made for dwellings. None of the following requirements need be applied for the charging point at a dwelling if it is not reasonably practicable to do so. This means that the requirements of this regulation may or may not be applied to a dwelling.


A dwelling is a self-contained unit, designed to accommodate a single household. Buildings exclusively containing rooms for residential purposes, such as nursing homes, student accommodation and similar, are not dwellings.

PME may be used in:


(i) Three-phase installations
The charging point is supplied from a three-phase installation which is used to supply loads
other than electric vehicle charging points and because the load characteristics are such that the maximum voltage between the main earthing terminal of the installation and Earth in the event of an open-circuit fault in the PEN conductor is not likely to exceed 70 volts.

Annex A722, item A722.2, gives information on load balance which relates to (i).


(ii) Installation earth electrode with very low resistance
The main earthing terminal of the installation is connected to an installation earth electrode, such, that, in the event of an open-circuit fault in the PEN conductor, the maximum voltage between the main earthing terminal of the installation and Earth does not exceed 70 volts.

An installation earth electrode is an additional earth electrode connected to the main earthing
terminal. Annex A722, item A722.3, gives guidance on determining the maximum resistance required for the earth electrode in (ii).

(iii) Disconnecting device
Protection is provided by a device which disconnects the charging point from the live conductors of the supply and from protective earth within five seconds in the event of the voltage between the circuit protective conductor and Earth exceeding 70 volts. The device need not operate if the voltage exceeds 70 volts for less than five seconds. Closing of the device is achieved by manual means only.

It requires the installation of an earth electrode for its operation. The operating coil of the device is connected between the main earthing terminal of the installation and the earth electrode. The device is based upon the BS 842 voltage-operated Earth Leakage Circuit-Breaker (ELCB).
But, as it is not suitable for this purpose, the device referred to in this regulation is distinctly different. Such a device is not yet commercially available but a product standard is believed to be in the process of development by a BSI Committee (PEL/23/1).
The 70V touch voltage figure is taken from Table 2c (Ventricular fibrillation for alternating current 50/60Hz) of IEC 60479-5 (Ed. 1.0), Effects of current on human beings and livestock – Part 5: Touch voltage threshold values for physiological effects. This standard gives a value of 71V for both hands-to-feet, in water-wet conditions with medium contact area (12.2 cm[SUP]2[/SUP]).

 

[Megavolt]

Dear god

 

[Guest125]

I took my reg from the latest amendment. Are your examples from an older regs book? Things may have changed?

 

[Silly Sausage]

I took my reg from the latest amendment. Are your examples from an older regs book? Things may have changed?

I take it you didn't pay any attention to what was new in Amendment 2 then?

You really aren't on the case at all, are you?!?!?!

 

[uksparks]

I took my reg from the latest amendment. Are your examples from an older regs book? Things may have changed?

I was looking at AMD 2, not 3.

 

[uksparks]

I take it you didn't pay any attention to what was new in Amendment 2 then?

You really aren't on the case at all, are you?!?!?!

Yes... its different to three.

 

[Guest125]

I take it you didn't pay any attention to what was new in Amendment 2 then?

You really aren't on the case at all, are you?!?!?!

I am sorry. I don't understand your point.

 

[shanky887614]

I am sorry. I don't understand your point.

green is amendment 1 and yellow is 3

 

[Guest125]

I know. I have the yellow book. I am a little lost now!!

 

[uksparks]

So going back to post #43, this was taken directly from AMD 3.

To me this says I DO NOT need to put a rod in. Whats your take on it?

 

[davesparks]

It's simple
UKsparks is working from ammendment 2, you are working from ammendment 3.

What could possibly go wrong?????

 

[shanky887614]

So going back to post #43, this was taken directly from AMD 3.

To me this says I DO NOT need to put a rod in. Whats your take on it?

if thats what has changed in amendment 3 you can follow either edition till July, ill have a look through mine when it arrives tommorow (BYB)

 

[davesparks]

So going back to post #43, this was taken directly from AMD 3.

To me this says I DO NOT need to put a rod in. Whats your take on it?

My take is that you cannot use a PME connection unless one of the three points are satisfied.
Without knowing more about (i) I wouldn't like to make any assumptions.
The device required to comply with (iii) isn't on the market yet I don't think.
(ii) is pretty easy to comply with if you wanted to, all you have to do is get a decent earth nest installed and connected to the MET.

 

[Guest125]

My take is that you cannot use a PME connection unless one of the three points are satisfied.
Without knowing more about (i) I wouldn't like to make any assumptions.
The device required to comply with (iii) isn't on the market yet I don't think.
(ii) is pretty easy to comply with if you wanted to, all you have to do is get a decent earth nest installed and connected to the MET.

A little beyond my ( in my head ) knowledge this is but I do think Dave seems spot on. If there was doubt though I would recommend an earth rod. Save on the extra core then. Just don't forget to CAT scan first.

 

[uksparks]

if thats what has changed in amendment 3 you can follow either edition till July, ill have a look through mine when it arrives tommorow (BYB)

Where did you get your BYB from? I was just looking on Amazon and they are out of stock.

I have not got the BYB yet, but have a copy of AMD3.

Looking at (ii), I did read somewhere that the resistance must be very low, something like less than 3 ohms maybe, does anyone have any clarification of this?

 

[Guest125]

if thats what has changed in amendment 3 you can follow either edition till July, ill have a look through mine when it arrives tommorow (BYB)

Yep. If you are planning to work for this customer again I would recommend installing to the 3rd. You don't want some idiot slagging you off in 7 months time saying "he gave you an out of date installation mate". Even though he would be wrong.

 

[uksparks]

A little beyond my ( in my head ) knowledge this is but I do think Dave seems spot on. If there was doubt though I would recommend an earth rod. Save on the extra core then. Just don't forget to CAT scan first.

I have got to dig a 2ft deep hole anyway for the mounting plate to be sat in, so can just dig across a little bit and see whats there, unlikely theres anything where this is going though.

What do you think? 2 rods maybe? Its next to a marina too, so the ground might be quite wet (if it leaks)

 

[Guest125]

Where did you get your BYB from? I was just looking on Amazon and they are out of stock.

I have not got the BYB yet, but have a copy of AMD3.

Looking at (ii), I did read somewhere that the resistance must be very low, something like less than 3 ohms maybe, does anyone have any clarification of this?

pre-ordered from IET. Arrived this morning. I only had the BBB and the NIC said either by the BGB or pre-order the BYB. So I went with the pre-order option seeing that my inspection was in November