High Ze - DNO added an RCD!

[DurhamSparky]

High ZE = YOU Found a Problem
DNO Contacted and Responded = No Longer YOUR Problem
Complete Test Certs as Usual and Note the Certificate about the Problem with High ZE and DNO

Walk Away with head held High!

 

[IQ Electrical]

It may not be a neutral problem at all, after all a PME system is just a glorified TT system. They may have problems with the stakes/spikes they had fitted, there may have been construction work further upstream that meant stakes were removed or having to be resited.

I go along with IQ here I think this is something temporary. I can not imagine the DNO just fitting an RCD and walking away. There may be a failing neutral but I bet you they are trying to find what it is and how to fix it.

The problem here, as it always is when a DNO is involved, is communication or a lack of it!

The DNO should be writing to the client, acknowledging that there was a problem, detailing what they did to make it safe and if that repair was a temporary measure, how they are dealing with the fault.

These mythical people just turn up, alter the characteristics of YOUR installation, leave no written evidence or certification for what was done and that could be the last you hear of it!

There's even an argument that the addition of an RCD 'between the meter and consumer unit' is notifiable

 

[malcolmsanford]

The problem here, as it always is when a DNO is involved, is communication or a lack of it!

The DNO should be writing to the client, acknowledging that there was a problem, detailing what they did to make it safe and if that repair was a temporary measure, how they are dealing with the fault.

These mythical people just turn up, alter the characteristics of YOUR installation, leave no written evidence or certification for what was done and that could be the last you hear of it!

There's even an argument that the addition of an RCD 'between the meter and consumer unit' is notifiable

Totally agree the DNO do not make themselves any friends with some of the attitude that is taken. Though far from being a red radical I felt that once again selling off the electrical grid system as not in our best interests, instead of dealing with a Central Electricity Board you now have to deal with several different ones, and then on top the supply companies who look after meters.

I have to say that at first I thought this thread was going to be about TN-S systems, as is was quite often found that these older ones had ELCBs fitted as well and by the DNO, but if I remember rightly these were before the meter, I maybe wrong with that.

Lol just see the DNO getting to grips with Part P ..................

 

[topquark]

Agreed, it should never have been sold off. As soon as it was the overidding motive became profit ... not in the consumers best interest!

 

[trebor]

I cant actually believe this, the ESQCR requires the DNO to maintain the Ze below the maximum of 0.35 for 100a TN-C-S system if they are supply the earth facility
Is it an S type RCD? they have fitted?
If not why bother to fit the 17th edition split ccu`s as there is now no dicrimination with the supply
Are they going to pop around once a quarter and press the test button on their rcd

This can not be acceptable as a permanent solution, if it was my job I would kick up a fuss about it and if nothing was done have their rcd removed and fit an s type 100ma as my main switch

 

[IQ Electrical]

ESQCR doesn't actually specify any max Ze values, the values are broad targets from an 'engineering agreement'.

Amazingly, there is no 'regulation' to force a DNO to comply with the 'engineering agreement' values!

 

[Chr!s]

I cant actually believe this, the ESQCR requires the DNO to maintain the Ze below the maximum of 0.35 for 100a TN-C-S system if they are supply the earth facility

ESQCR mentions no max figures for tncs

This can not be acceptable as a permanent solution, if it was my job I would kick up a fuss about it and if nothing was done have their rcd removed and fit an s type 100ma as my main switch

Not too much you can do about, you could TT it.

Is it an S type RCD? they have fitted?
If not why bother to fit the 17th edition split ccu`s as there is now no dicrimination with the supply
Are they going to pop around once a quarter and press the test button on their rcd

The ESQCR requires equipment of the dno and suppliers to ensure their equipments meets BS 7671, so an s type would ensure this.
If you have a 100 fuse and your ZE is 0.55 ohms this may be down to network parameters, but this wouldn't comply with BS7671, so they stick an rcd in to comply

 

[Chr!s]

Beat me to it