DT1991
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When put into maths it requires a stupid low Ra value which cannot in reality be sustained.Why not the supplementary earth rod path?
That's my understanding?
Discuss EV Charger Installation - Cabling Query? in the Electric Vehicles Advice Forum area at ElectriciansForums.net
When put into maths it requires a stupid low Ra value which cannot in reality be sustained.Why not the supplementary earth rod path?
When put into maths it requires a stupid low Ra value which cannot in reality be sustained.
That's my understanding?
Yes we did some calcs at college when we did the course. It was nigh on impossible. I think 3 earth rods 1 meter apart 2.4 meters deep might do it. Depending on resistivity of the earth.When put into maths it requires a stupid low Ra value which cannot in reality be sustained.
That's my understanding?
[/QUOTE]I dont think the maths is the same.
When PME and using a supplementary earth rod it takes into account the max current of the installation and this is put into the equation which brings up a low Ra value.
These are not my suggestions, they are what I was taught on the City & Guilds course in EV charging that I did. I dare say that anyone else who has completed the course would have been taught the same.
If these 'suggestions' amuse you, why not e-mail Bill Allan of NAPIT and laugh loudly at him while you tell him that you know more about EV charging than he does. Meanwhile, kindly desist from trying to me appear foolish. Fair enough?
https://professional-electrician.com/18th-edition/changes-introduce-shock-risk
if the prohibition of PME for EV chargers is to eliminate risk if the supply N is lost (as with metalclad caravans) the I can't see any reason to differentiate between inside or outside. a fault occuring would have a similar result, in or out. then, i have not done any research on EV so my knowledge is limited.
The attached scan is from section 5.3.3.3.1, page 32 of the Code of Practice for Electric Vehicle Charging Equipment Installation. The section heading is: Providing a TT earthing system for the charging equipment.
So how do you ensure that the zone of influence of the earth electrode does not overlap the zone of influence of any metalwork connected to the PME earth?
Do you trace and map out every gas and water pipe, buried structural steel etc?
Do you get accurate maps from the DNO showing the extent of the zone of influence of every buried PME electrode in the street, street furniture, repurposed PILC cable etc?
Yes we did some calcs at college when we did the course. It was nigh on impossible. I think 3 earth rods 1 meter apart 2.4 meters deep might do it. Depending on resistivity of the earth.
So they have given us a solution to the problem that is pretty pointless.
How many electricians install an earth rod for an outdoor socket on a pme system, supplementary or otherwise. Cant see much difference myself.
Ha ha, your electrician will be thinking "sxxx, he knows his stuff!"Hi,
I got back in touch with the installer.....and sent the following email:
"There is something I was looking to clarify with you in relation to my recent charger installation.
As you know the charging unit is located internally in my garage, as my primary intensions will be to charge whilst the car is parked inside the garage overnight.
However, as the selected location of the charging unit is next to the garage door, I had also anticipated that the unit could be used for outside charging as the cabling could easily run under the garage door.
A friend of ours has a similar EO installation where their charger is also located internally next to the garage door like ours, therefore enabling him to charge either indoors or outdoors.
However, he had pointed out to me that in order to charge outside there are some safety regulations required on the earthing requirements of the install; such that their installer had advised that an Earthing rod would be required.
It appears within my installation, the charging unit is setup to use our domestic earthing system (i.e. T-N-CS (PME)) and not via an Earthing rod?
I had checked out the EO website regarding this requirement, and as per the latest 18th edition regulations (Section 722.411.4.1) it does appear to state that PME earthing systems should not be used for any outdoor charging, and that the primary mechanism should be an Earthing rod for the EO charging unit.
It looks like this regulation is primarily there as a protection against the risk of fatal shock hazards caused from faults within the supply network of earthing systems (i.e T-N-CS (PME))
So having come across the above information, I am naturally concerned particularly on the safety aspects if one was to charge outside?
As I’ve mentioned, the primary use will be charging indoors, but with the possibility of future and occasion-use for outdoor charging in mind – Hence the selected location of the charging unit is located next to the garage door; allowing cabling to reach the front of the driveway.
Prior and during the install, I was not made aware that there would be any issues based on my anticipated use-cases; and likewise there were no earthing requirements highlighted for consideration.
However, these latest regulations seem to suggest otherwise, and therefore I would want to obtain clarification that I am safe to use the charger as intended (i.e. both indoors and outdoors)
Or is it the case that the earthing setup will need to be changed to cater for outdoor use i.e. Earthing rod?
If an Earthing rod must be used, would I still be able to charge safely whilst parked inside the garage as per my primary intended use i.e. assessment of any extraneous conductive parts that are simultaneously touchable with the vehicle or charge point etc."
Hi,
I got back in touch with the installer.....and sent the following email:
"There is something I was looking to clarify with you in relation to my recent charger installation.
As you know the charging unit is located internally in my garage, as my primary intensions will be to charge whilst the car is parked inside the garage overnight.
However, as the selected location of the charging unit is next to the garage door, I had also anticipated that the unit could be used for outside charging as the cabling could easily run under the garage door.
A friend of ours has a similar EO installation where their charger is also located internally next to the garage door like ours, therefore enabling him to charge either indoors or outdoors.
However, he had pointed out to me that in order to charge outside there are some safety regulations required on the earthing requirements of the install; such that their installer had advised that an Earthing rod would be required.
It appears within my installation, the charging unit is setup to use our domestic earthing system (i.e. T-N-CS (PME)) and not via an Earthing rod?
I had checked out the EO website regarding this requirement, and as per the latest 18th edition regulations (Section 722.411.4.1) it does appear to state that PME earthing systems should not be used for any outdoor charging, and that the primary mechanism should be an Earthing rod for the EO charging unit.
It looks like this regulation is primarily there as a protection against the risk of fatal shock hazards caused from faults within the supply network of earthing systems (i.e T-N-CS (PME))
So having come across the above information, I am naturally concerned particularly on the safety aspects if one was to charge outside?
As I’ve mentioned, the primary use will be charging indoors, but with the possibility of future and occasion-use for outdoor charging in mind – Hence the selected location of the charging unit is located next to the garage door; allowing cabling to reach the front of the driveway.
Prior and during the install, I was not made aware that there would be any issues based on my anticipated use-cases; and likewise there were no earthing requirements highlighted for consideration.
However, these latest regulations seem to suggest otherwise, and therefore I would want to obtain clarification that I am safe to use the charger as intended (i.e. both indoors and outdoors)
Or is it the case that the earthing setup will need to be changed to cater for outdoor use i.e. Earthing rod?
If an Earthing rod must be used, would I still be able to charge safely whilst parked inside the garage as per my primary intended use i.e. assessment of any extraneous conductive parts that are simultaneously touchable with the vehicle or charge point etc."
Ha ha, your electrician will be thinking "sxxx, he knows his stuff!"
I think that's well worded hyeung, however from the little I've seen of your posts you're not one to just accept a half answered question. I wonder what you will do if he just says says 'yes, it's fine for outside'!
Let us the know the response and then we can start the discussion all over again.
Reply to EV Charger Installation - Cabling Query? in the Electric Vehicles Advice Forum area at ElectriciansForums.net
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