PME, TN-S ??

[goasis]

Hi, a customers earthing arrangement in TN-S. Main earthing conductor 6mm and clamped (loosely) onto outside of supply cable.
Having spoken to DNO regarding this they email me saying they will send someone to see if PME is available. The email states PME is the ONLY way they provide an earth connection to their network. If its not available it is up to the electrician to sort out.

DNO came out today. Tightened the clamp and changed to 16mm conductor. No PME label. So what am I left with? Its definitely a TN s cutout.

As an aside, the email had the interesting sentence "as the property owner, there are various types of earthing you can choose for you home"

 

[buzzlightyear]

DID YOU TAKE A PIC .

 

[goasis]

DID YOU TAKE A PIC .

 

[buzzlightyear]

now it is TN-S system .

 

[goasis]

now it is TN-S system .

Its always was, have I misunderstood? TN-S and PME? ZE readings were all good (0.2 from memory)

 

[buzzlightyear]

Its always was, have I misunderstood? TN-S and PME? ZE readings were all good (0.2 from memory)

maximum tn-s -0.8 tn-c-s -0.35 TT 0.21

 

[buzzlightyear]

How to Determine Earth Fault Loop Impedance

More expert advice from the team at ELECSA. This article explains why it is necessary to determine the values of earth fault loop impedance (Zs) for new installations and for those in service that ar

professional-electrician.com

 

[LastManOnline]

now it is TN-S system .

Why don, t service providers just label the supply (or supply change) and remove all the guesswork?

 

[Deleted account]

No guess work required for this one. It is as @buzzlightyear states TN-S.

 

[LastManOnline]

No guess work required for this one. It is as @buzzlightyear states TN-S.

Not doubting"buzzlightyear"s expert eye, but just wondered why an easier means of determining the current supply arrangement was, nt made available

 

[Deleted account]

Not doubting"buzzlightyear"s expert eye, but just wondered why an easier means of determining the current supply arrangement was, nt made available

Yes agree. Sometimes a supply looks like it is pme as earth cable goes into the cut out, but sometimes it’s TN-S.

not all TN-S supplies are clamped onto the lead sheath.

 

[goasis]

Sorry, I wasn't doubting it was TN-S, just questioning why the DNO told me they only provide PME, but then came and changed the size of the earthing conductor on this supply.

 

[ipf]

Hi, a customers earthing arrangement in TN-S. Main earthing conductor 6mm and clamped (loosely) onto outside of supply cable.
Having spoken to DNO regarding this they email me saying they will send someone to see if PME is available. The email states PME is the ONLY way they provide an earth connection to their network. If its not available it is up to the electrician to sort out.

DNO came out today. Tightened the clamp and changed to 16mm conductor. No PME label. So what am I left with? Its definitely a TN s cutout.

They only provide PME.......but they repair/improve TNS.

Whichever's the easier, I suppose.

 

[Deleted account]

Sorry, I wasn't doubting it was TN-S, just questioning why the DNO told me they only provide PME, but then came and changed the size of the earthing conductor on this supply.

No need to be sorry.

we where just having a debate within your thread regarding identifying earthing systems.
as for your original post. I agree it’s a bit strange that they said what they said considering they came out and contradicted this and actually sorted the TN-S loose clamp.

DNOs a law unto them selves.

 

[buzzlightyear]

Sorry, I wasn't doubting it was TN-S, just questioning why the DNO told me they only provide PME, but then came and changed the size of the earthing conductor on this supply

now doubting Thomas why did you not see if it was a TNCS obesely the earth would be tagged to the neutral.

 

[goasis]

No need to be sorry.

we where just having a debate within your thread regarding identifying earthing systems.
as for your original post. I agree it’s a bit strange that they said what they said considering they came out and contradicted this and actually sorted the TN-S loose clamp.

DNOs a law unto them selves.

Thanks, I was questioning my understanding thats all. And I love the idea that homeowners can choose from a variety of earthing systems!!! (I suppose in theory you could 'choose' TT)

 

[goasis]

now doubting Thomas why did you not see if it was a TNCS obesely the earth would be tagged to the neutral.

Obviously, and it wasn't, which is why I said it was TN-S

 

[Deleted account]

Thanks, I was questioning my understanding thats all. And I love the idea that homeowners can choose from a variety of earthing systems!!! (I suppose in theory you could 'choose' TT)

Actually I think in the present dropped neutral risks TT may be the safest in future.

 

[buzzlightyear]

i have recently tested a property and TNS TO PME just like that has tommy cooper says .

 

[UNG]

Why is there appears to be no standard policy for DNO's when it comes to earthing.
The two DNO's local to me I'm sure would have replaced the clamp with a constant force spring and used a 16mm earth braid to the main earth terminal