Cable size

[uksparks]

I thought you were going 16mm^ now ?

Sorry I don't know why I said 10mm, hang about, would it have to be 16mm as its strictly speaking a main earthing conductor.

 

[uksparks]

all this hassle for charging a toy car. :icon6:

I know, its silly isnt it!

 

[davesparks]

Can I not connect it to the armouring to take it back to the MET or the CPC of the circuit? Do I have to run in another 10mm earth, I then have the hassle of protecting the earth cable when it leaves the wall and into the ground...

It is up to you, I have presented my reasoning for connecting it directly back to the MET. If you think this is wrong or whatever then you don't have to follow it.

 

[uksparks]

what about connecting to the rebar in the reinforced concrete base?

This is the base, its only about 300mm deep.

 

[spark 68]

what about connecting to the rebar in the reinforced concrete base?

Dave mentioned that way way back lol

 

[uksparks]

It is up to you, I have presented my reasoning for connecting it directly back to the MET. If you think this is wrong or whatever then you don't have to follow it.

I accept what you are saying and fully understand why you have come to that way of thinking, but just to put a charger in, it seems a little like I am suddenly taking on the entire installation and trying to protect that opposed to just my bit of work.

 

[davesparks]

Sorry I don't know why I said 10mm, hang about, would it have to be 16mm as its strictly speaking a main earthing conductor.

Of course not, I'd be inclined towards 10mm as it will be subjected to the same currents as the main bonds.

 

[Guest125]

You say not to the MET...



You say at the end of the circuit.



You say to the MET



You are now saying to the MET.

Which is it??

Me personally right now would earth at the end of the circuit. BUT, Wednesday when I am in the office I am going to look at what the other guys said, compare this to what I can find in the BYB and make a decision about how I would do it in the future.

Remember. YOU need to be happy that it complies.

 

[Leesparkykent]

Dave mentioned that way way back lol

trying to steal dave's thunder lol

 

[uksparks]

Me personally right now would earth at the end of the circuit. BUT, Wednesday when I am in the office I am going to look at what the other guys said, compare this to what I can find in the BYB and make a decision about how I would do it in the future.

Remember. YOU need to be happy that it complies.

My BYB will arrive on Wednesday too so will look then. I think it will probably end up just being a rod(s) at the end of the circuit.

 

[Guest125]

My BYB will arrive on Wednesday too so will look then. I think it will probably end up just being a rod(s) at the end of the circuit.

Would be more cost effective for the client too. I get grief for being 'a rip off merchant' in other threads so hopefully this suggestion wins me some brownie points back.

 

[davesparks]

My BYB will arrive on Wednesday too so will look then. I think it will probably end up just being a rod(s) at the end of the circuit.

What are you installing the earth electrodes for? to comply with item (ii) of that list that allows you to connect to the PME earth it specifies that they be connected to the MET doesn't it?

 

[uksparks]

What are you installing the earth electrodes for? to comply with item (ii) of that list that allows you to connect to the PME earth it specifies that they be connected to the MET doesn't it?

It is connected back to the MET via the CPC, play on words... i'd say it open to interpretation.

 

[uksparks]

What are you installing the earth electrodes for? to comply with item (ii) of that list that allows you to connect to the PME earth it specifies that they be connected to the MET doesn't it?

Hmm "An installation earth electrode is an additional earth electrode connected to the main earthing terminal."

I won't win with this one will I, I need to run one back to the MET really don't I. Ill call the NICEIC in the morning and ask them their opinion on it, im sure they will put some other spin on it that doesn't exist.

 

[spark 68]

trying to steal dave's thunder lol

No I would disagree slightly with Dave in that I would use at least 16mm (> 1/2 the tail/N size @ 25mm^), my reasoning is because if we are going with bonding back to the MET as a backup for a broken suppliers Neutral and going with very low Ra readings we could end up with substantial diverted current flow from the 3 phase supply for the entire building, albeit the normal Main Bonding conductors will share some of this burden but for the relatively small run I would prefer the larger size if the worst case was to happen.

 

[Guest125]

Oh no. You mentioned the N word! Brace yourselves.

 

[davesparks]

Hmm "An installation earth electrode is an additional earth electrode connected to the main earthing terminal."

I won't win with this one will I, I need to run one back to the MET really don't I. Ill call the NICEIC in the morning and ask them their opinion on it, im sure they will put some other spin on it that doesn't exist.

I dread to think what that bunch of crooks will have to say about it!

I thought you'd done the vehicle charging point installation course? Did they not cover all of this on that course? if not then what exactly was the point of the course?

 

[Guest125]

No I would disagree slightly with Dave in that I would use at least 16mm (> 1/2 the tail/N size @ 25mm^), my reasoning is because if we are going with bonding back to the MET as a backup for a broken suppliers Neutral and going with very low Ra readings we could end up with substantial diverted current flow from the 3 phase supply for the entire building, albeit the normal Main Bonding conductors will share some of this burden but for the relatively small run I would prefer the larger size if the worst case was to happen.

Now ow that is just showing off now isn't it?

 

[Guest125]

Popcorn

 

[davesparks]

No I would disagree slightly with Dave in that I would use at least 16mm (> 1/2 the tail/N size @ 25mm^), my reasoning is because if we are going with bonding back to the MET as a backup for a broken suppliers Neutral and going with very low Ra readings we could end up with substantial diverted current flow from the 3 phase supply for the entire building, albeit the normal Main Bonding conductors will share some of this burden but for the relatively small run I would prefer the larger size if the worst case was to happen.

I can see your point with this, but what are the chances that the building is going to be so far out of balance that the neutral current is going to be that great?

plus I would suggest that it depends on how you connect the rods, I have assumed (possibly incorrectly) that each rod will be connected individually and that there will be multiple rods sharing the current (as this is the way I do it)