Replacing a VOELCD ?

[JohnW2]

Not really bouncing it back, just trying to highlight that once you admit shades of grey you find far more of them.

As I said, it's not really "more of them" - merely two specific examples of the very situations I was asking you about.

Another issue, of course, is that of what the customer will allow to be done, since they clearly can't be forced to accept, and pay for, any particular work.

Indeed not, but they can be denied work if they will not accept any required consequentials.

Of course - and that's obviously the question underlying my question - should they "be denied work if they will not accept any required consequentials"? That's why I was interested to hear how electricians approach this.

In common sense terms, it would not seem very reasonable to deny the customer work to remedy a problem/danger (e.g. replacing a damaged accessory or repairing a damaged cable) if the installation was left in no less safe a state (in fact, safer) than it had been before, because they were not prepared to have work undertaken to bring the circuit up to current standards.

Do you have any personal views in relation to specific scenarios? For example, do you not think that an electrician should be prepared to replace a faulty RCD in a single-RCD (all circuits) CU?

Kind Regards, John

 

[streetlighter]

Some intresting points are being raised in this thread, so i will chip in with some of my experiences i suppose its a case of the regs versus reality in someways.

A couple of years ago i got a call to go and quote some electrical works, extra sockets, replace light fixtures etc, At the clients property the bathroom ceiling was down and i could see junction boxes with no lids on that would become inaccessable, there was evidence of recent DIY electrical work had been carried out.
The CU was a Square D this had a massive cutout in the bottom and looked second hand, i asked and apparently it was fitted by an "Electrician" friend a few months back. No RCD protection just a main switch multiple circuits fed of each MCB
The main bonding conductors where 2.5mm ! So i gave a price for the work which included a new consumer unit with RCD protection and upgrading the bonding.
Well the client said that the other electrician who quoted would do just the work she wanted and was cheaper, so i walked away from this one.

A couple of weeks ago i installed an extra socket outlet onto an existing circuit that had no RCD protection. the cable was surface mounted and the socket was feeding a freezer so not portable equiptment.
I assessed the risk on the job and made a note on the minor works about the lack of RCD protection.

 

[Nemo2000]

A man came yesterday from the DNO (Western Power Distribution) to look at my VOELCD......

He agreed that it had the seals and labels to show that it had been installed originally by SWEB. However, he said that WPD would not replace it because they "did not have the electricians"! Yet at the same time he said they could replace it with a simple double-pole isolater switch, so that I could then employ an electrician to install a RCD on the consumer side! The logic of this apparent inconsistensy baffles me

 

[securespark]

I thought VOELCBs had to be replaced.

To my mind, that statement is correct, certainly when installed on a TT supply, which, in my 30 years experience, they almost exclusively have been.

They were deleted from the regulations in 1985 because they were deemed unsafe.

They were deemed unsafe because the way they operate could present a serious shock risk to people.

Nemo, If the DNO accepts ownership of the VO ELCB, I'd insiust on a change. Whether they have an electrician to do the job or not is not your worry, it's theirs. They can sub-contract.

 

[securespark]

If this was consumers equipment, I'd issue a minor works covering the replacement of the RCD only.

The installation is not compliant with the current edition of BS7671, but it is not in a dangerous condition.

Much the same as I'd replace a damaged socket front supplied from an old BS3036 fuse with no RCD.

What about replacing a damaged CU?

What about, having been asked to fix a lighting problem, replacing an existing metal switch on a circuit with no cpc and no RCD?

What about replacing a section of damaged cable buried in a wall that was in the wrong place and/or had no RCD protection? Would you re-bury it because that's how it was?

Surely, the key words were:

but it is not in a dangerous condition.

So, an installation that was, would be dealt with differently.

once you admit shades of grey you find far more of them.

There's 50 of them, right?

 

[Nemo2000]

I have written back to the DNO for clarification

It seems odd to me that they will accept responsibility for changing it to an isolator switch, but NOT to a RCD. The only difference that I can see is that the RCD would involve connection to the earthing rod, of which the DNO disclaims responsibility.

[The DNO's engineer considered that it would be quite acceptable to leave the supply as TT and fit a RCD with an earth rod connection. Upgrade to PME would depend upon whether the earth sheath is continuous along the 'daisy chain' supply of all three houses - that would need to be checked. But is the TT + earth rod is OK, then why bother with more work?]

I will keep pushing at the DNO, but if they just refuse then I am not sure what more I can do?

Ironically, the DNO chap offerred to pull the supply fuse and test the earth sheath time, but warned that - once the VOELCD went off - it might not come back again because "these things are known to become unreliable with age" ! When I asked what I should do if it ever tripped off and then would not reset (through age/mechanical failure) the answer was to look in Yellow Pages and call an electrician !!!

 

[bernardgreen]

They were deemed unsafe because the way they operate could present a serious shock risk to people.

They would still operate when the CPC reached 50 volts ( unless the mechanism was defective ). The problem with them was parallel paths from CPC to ground that diverted current from the coil ( which requires current to operate ) in the VOELCB when there was a fault. This could mean very high fault currents had to flow in a low impedance parallel path(s) before the the CPC reached a voltage high enough to operate VOELCB.

The more likely risk was fire from high fault currents in parallel paths.

 

[ban-all-sheds]

There's 50 of them, right?

I believe that's sparkybird's area of expertise.

 

[Nemo2000]

Well, I got in touch with the 'energy supplier' EDF and, as expected, they claimed that it was the responsibility of the DNO. However the DNO claims that the relevant part of its business was sold off to SEC (who now?) some years ago and disclaim any responsibility for it. Yet, at the same time, they are prepared to come and remove it and replace it by a plain isolator switch!

Between the VOELCD and the two CUs there is a terminal block in the tails (incoming pair > 2 outgoing pairs) which also was installed by SWEB originally and still has their seal. My argument therefore is that the boundary between the 'supply installation' and the 'domestic installation' is between that terminal block and the CUs, therefore the VOELCD is part of the 'supply installation'. Would I be right?

Problem is - how do I find the right part of whatever organisation to persuade someone to accept responsibility for replacing it?

 

[securespark]

I would say that you are right. SWEB installed it & the DNO ought to take responsibility for it now. As you say, they are willing to fit a switch, but not an RCD. Possibly because one RCD covering the whole installation is not compliant with current regulations.

But it is miles better than nothing! Did you establish the supply as TT?

What does westie reckon?

If the DNO fit an earth terminal to their supply cable and this is extended to your installation, then, strictly, an RCD is not absolutely necessary but the installation will not be to current standards.

 

[westie101]

What does westie reckon?

Personally I would say (and have) that the DNO should change it!

Having said that there is no mention of them in any legislation or documentation that we hold! So it is a "fallen between the cracks" situation brought about by privatisation.
In this case I would suggest that the isolator installation be accepted and then fit one or more RCDs, as I doubt that WPD will change their stance without a lot of pressure

(as a side comment we do have replacements available and do occasionally fit them where there is no other RCD protection)

 

[TheKeymeister]

I know it varies from area to area, but in my part of WPD, we have been recently told that anything past the cutout, including tails, meter board and box etc, is the responsibility of the supplier or the customer. It also says in documentation that when we fit an RCD it is then adopted by the customer and is the customer's responsibility to maintain, so I can see where they are coming from (rightly or wrongly)

Considering we usually charge for an isolator (and don't do LV isolations on request), it sounds like you got a decent offer.

 

[securespark]

Personally I would say (and have) that the DNO should change it!

Sorry, westie, I missed that.

 

[Nemo2000]

The supply is TT. However, my house is at the end of a 'dairy-chain' of 3 houses, rather than direct from the main cable in the road, so it is not known if the cable sheath in fact has a continuous connection at the intervening houses. The WPD's engineer did go to check, but I don't think that he got access, and certainly he never came back to update me.

According to him, a RCD in place of the VOELCD should work quite happily with the existing TT supply and earthing rod, so actually I think that 'earthing' is a bit of a red-herring here.

[ Ironically, he did also offer to pull out the main fuse and test the cable sheath continuity from my house, but warned that - given the reliability problems of old VOELCDs - he couldn't guarantee that it would go back on again afterwards! And if it didn't, then WPD wouldn't do anything about fixing it!! ]

Latest info from WPD advises that they would charge for replacing the VOELCD by an isolator. They still haven't explained how they can do that if their excuse for not installing a RCD is that they "do not have any electricians"!

My preference is simply to rpelace the VOELCD by a RCD in the same physical location - there is room. If the VOELCD is replaced by an isolator switch, then the RCD has to go somewhere else on the far side of the meter board, meaning lots of re-routing (and probably replacing) of the tails to the 2 CUs. I want the path of least disruption .

To pick up on TheKeymeister comment, if WPD would want me to accept responsibility for the RCD, then fine - but first they have to fit!

 

[TheKeymeister]

Latest info from WPD advises that they would charge for replacing the VOELCD by an isolator. They still haven't explained how they can do that if their excuse for not installing a RCD is that they "do not have any electricians"!

My preference is simply to rpelace the VOELCD by a RCD in the same physical location - there is room. If the VOELCD is replaced by an isolator switch, then the RCD has to go somewhere else on the far side of the meter board, meaning lots of re-routing (and probably replacing) of the tails to the 2 CUs. I want the path of least disruption .

To pick up on TheKeymeister comment, if WPD would want me to accept responsibility for the RCD, then fine - but first they have to fit!

I did think it sounded too good to be true that they'd offered you an isolator for free!

As I understand it, fitting an RCD would need to be done by an electrician as it could start tripping due to any existing faults with the customers installation. We're not allowed to touch a customers installation. An isolator is different as it's not going to change or introduce any problems.

I suppose because it lurks in the area where the responsibility is now of the supplier, that's why they wouldn't replace it. As said before because the original electricity board has been carved up into separate companies it doesn't exactly help with who's responsible for what.