OVO NEARLY CAUSED A CATASTROPHIC HOUSE FIRE

Hey ​@Faz890,

Welcome to the community! If you haven’t already please check out our newbies area. 

I'm sorry to hear about your experience. When you requested your meter upgrade, did you also request an upgrade for the tails as part of the work? If this wasn’t specified at the time, the engineers would not carry out additional work unless it was agreed upon and paid for in advance. You can find more information on the available jobs and their associated costs that can be arranged with our engineers below:

I’ve asked one of our internal head engineers to take a look at the thread to give a better understanding of what went wrong here. 

If you are unhappy with the resolution provided after raising your complaint, you can find more information regarding our complaints process and how to escalate this issue.

Hi Chris, 

This wasn't clarified at the time and I assumed that the wires would get changed alongside the meter. The charger was preinstalled and was there before the meter. When I requested the meter change, I specifically mentioned it was for the EV. 

I was told the meter tails would have been changed for free with the smart meter but I had no idea this had to be requested and it wasn't clarified. 

As part of the safety checks after install, the tails being undersized wasn't picked up which eventually led to an overloaded system. 

I was then offered £10 for the mixup after I mentioned the lack of safety awareness and confusion. The bare minimum would have been to replace the tails and an apology for the mixup. At the time, I did not want any monetary compensation, just for the tails to be changed. 

This is a major health and safety breach and could have ended differently had it not been for the fuse breaker. 

Am I missing something here?
(I may be because you don’t give any dates of what work was done when).

Surely if the particular charger requires 25mm tails rather than 16mm then they should have been changed at the time that the charger was installed?
Otherwise it would be the installer of the charger who had installed it in a potentially unsafe state.

If they weren’t changed at that time then what you describe could have happened at any time after the charger was installed. (New meter or not).

Hi Nukecad,

The tails from the main supply to the meter are the responsibility of the energy supplier. The consumer is not allowed to replace or repair these wires. This is something the energy supplier changes for free when a new meter is installed. 

All other wires are installed properly and checked for safety. 

Thanks  I was aware of all that.

And by the way, I forgot to mention before that it's good to hear that the fuse did its job and you had no fire.

The fact remains though that if the tails are not changed at the same time as the charger is installed then that leaves a potential for overheating and in the worst case a fire.

Luckilly in this case the fuse blew before things got that far. (As it's meant to do).

Maybe your experience is an example of why it may not be such a good idea to try and save on the cost of replacing the tails at the time that the charger is installed and instead leaving it until (months?) later.

PS. Some lower power EV chargers are fine with 16mm tails.

Should a meter engineer be aware of every different make/model of charger and their power requitements? Remembering that everything after the meter is the consumers property/ responsibility.

Nukechad,

I think your forgetting the main point, the safety check conducted by the engineers was flawed. When the charger was installed, it was done before getting the new smart meter. The tails upgrade were anticipated to be done with the smart meter and they weren't.

Customers aren't always aware of safety measures and the responsibility falls on the supplier. The engineers should have picked this up at the time of installing the smart meter. OVO were aware what make the EV was due to the Charge Anytime requirements. OVO should have asked or recommended tails upgrade for new EV customers. 

There seems to be a breakdown of communication with the company and the engineers installing the new meters. Maybe OVO can incorporate this into future meter installing safety precautions. 

If a service is free in certain situations, why are OVO not offering this? Why should the customer request this? It should be offered at the point of recommending a new smart meter. I really liked OVO and their customer service up until this incident has been amazing. I really like the company and they have some good rates. 

I just feel that they could have approached this better, especially when safety was involved. It's not like the customer can do this work, they're prohibited. 

I think that we will have to agree to disagree.

I will note in fairness that your posts do state “assumption/assumed”, “anticipation/anticipated”.

Maybe your expectations were more than what actually happens?

Nukecad,

One can only use assumption or anticipation in hindsight. A customer won't necessarily know what is available or different policy and processes. This is why it's important for the supplier to make the customers know in advance. 

OVO can do the right thing and fix this problem and keep me as a loyal customer. I actually recommended the company to my friends and family who all have EV's. 

Hey ​@Faz890,

I have forwarded this to our internal head engineer for his input.

Initially, when you had the charger installed, the installer should have conducted a site survey. This survey would have identified the issue with the tails needing replacement, and that work should have been completed then. The same applies to the fuse.

During our engineer's visit, we were not informed that the tails required upgrading. As ​@Nukecad has correctly pointed out, some EV chargers can function with 16mm cables; this depends on the charger and the amount of current it draws. It would have been difficult for us to determine that this work was necessary unless we were the ones who installed the charging point, which, to my understanding, we did not do.

I have spoken with your complaints handler and requested that they reach out to you to see how else we can assist you.

Hi Chris,

The installer did do the check and informed me that the tails would need to be upgraded. Having read your forum, I found that this work is normally done with the change of smart meter (free). I assumed this was the case but did not know it has to be specially requested. 

A customer will not always know this information and in my case the safety check was signed off by the smart meter installer. The system was not safe and it shouldn't have been signed-off. 

I was always under the impression that the tails had been changed, there was no need for me to consider they weren't. It wasn't until the blown fuse that I was told they were not changed. 

My argument is that the changing of tails should be offered to all customers with EV chargers (at the point of a meter change). Customers won't always know if they need 16mm or 25mm tails. In a worse-case scenario, a house could go up in flames. 

OVO as a company does have a duty of care to customers and if something like this has been raised, they need to inform the customers with EV's to get the work checked. 

All I ask for is for the tails to be changed. It would have been free at the point of installing a new smart meter. It's unfair for me to pay for something which the safety check should have picked up on. 

There is still a technical error here that has not been resolved. You said: 

                    … As part of the safety checks after install, the tails being undersized wasn't picked up which eventually led to an overloaded system. ...

It is completely impossible for undersized tails to cause an overload. The DNO fuse blew because of either a current in excess of the fuse rating or that it was faulty.  Undersized tails cannot cause an increase in current. Undersized tails can only result in overheating and damage to the tails specifically which is why the tail size is increased to prevent damage to them.

To that extent the reason for the overload that caused the fuse to blow has not been identified and still remains a potential problem even if tails are now correctly sized.

One possibility exists. When the tails were 16mm2 the charge point should be set to a maximum of 16A / 3.5kW until the tail size had been increased and the DNO had checked and resized the fuse if necessary. My guess is that the fuse was 60A. To allow the charge point to run at 32A / 7kW the DNO would have to change the fuse to 80/100A and OVO change the tails to 25mm2 between the fuse and the smart meter. Somehow the charge point was set to 32A and along with the other loads in the house exceeded the 60A fuse rating. That's what caused the fuse to blow, not the tails.


Peter

What size was the main fuse that blew?

NG were the first DNO, I think, to stop installing 100A fuses as standard in domestic premises, opting rather for 80A. This still allows for a load of up to 18kVA, enough for both an ordinary EV charger and some heating equipment. 16mm² of copper is quite enough for 80A, especially over the few inches normally between the cut-out and the meter. Which safety provision does your electrician think was violated?

Hi Peter, 

National Grid confirmed the old fuse was 80amp, same as the new one. 

No new appliances have been fitted and nothing has changed. Nothing new in my routine either. I don't understand what could cause the overload apart from the EV being on. 

My electrician did say that the burning smell could be from the 16mm tails overheating. There's no burn marks on any wires. 

Hi Firedog,

The old fuse was 80amp and the new one is the same. Would a 100A be better situated in my situation? 

The burning smell which emitted when the fuse blew was attributed to the tails. Had the tails been 25mm, they would have dealt with the load power suitably. 

As a piece of information not necessarily relevant, the marking on the fuse carrier is not the size of the fuse. It's the rating of the fuse carrier. Mine says 60/80A but it is fitted with a 60A fuse as I'm on a looped supply but houses not looped can also have 60A fuses as standard, particularly on older properties.

​@Firedog You are absolutely correct to say DNOs fit 80A fuses these days as part of the diversity calculation for their substations. It means more customers can have an EVSE fitted without technically having to upgrade the substation. It's a similar diversity calculation as you would have in a consumer unit relative to the DNO fuse rating.

If the DNO fuse blew then the wiring would have taken a bit of hammering and, as you said, even if there are no scorch marks they can smell. Other high power devices likely to cause an issue are 8/9kW electric showers, electric ovens washing machines but this group of devices don't normally take full power for very long periods of time. At 100A an 80A fuse will hang in for as long as four hours (checked information). They are there to prevent short circuits starting a fire in the wiring between the DNO fuse and the consumer unit because under those conditions they will blow very quickly and with a considerable bang.

Peter

https://www.northernpowergrid.com/sites/default/files/assets/Northern%20Powergrid%20LCT%20installer%20stakeholder%20communication%20July%202023.pdf

​@Faz890 Do you happen to have the smart meter data for the event?

It was either a catastophic short or the consumer unit took a huge current for an extended period of time amounting to up to 100kWh of power being consumed over a period of hours given the current and the duration taken to blow the fuse. I’m concerned that you still have a serious, unrectified fault on your system at present as undersized tails was not the cause of the problem.

Peter

Hi Peter,

100KWh is impossible. I have checked my meter data and it shows max 20KWh, that was including my EV being charged. The electrician has seen the wiring and nothing has come up. Apart from the 16mm wiring issue. I also have surge protection unit separate for the EV charger. Nothing was tripped before the outage. 

Undersized tails cannot cause an increase in the current. If anything they reduce the current very slightly due to their slightly higher resistance. There is still no root cause for the fuse blowing. It's as simple as that.

With regards to surge protection they can fail short circuit and can blow the fuse but the indicators will be showing red to say that they have either failed or come to the end of their life. When surge protection works properly they they absorb the spikes by drawing up to 40,000A but the energy in the spike is nowhere near the energy required to blow the fuse by many orders of magnitude.

https://www.youtube.com/watch?v=cZC-fNSX2eg&t=35s

Peter 

The safety issue is still present. If the tails are getting hot, there is a fire risk should they melt. They should have been replaced. OVO still need to rectify the problem. 

Wiring regs say 16mm2 is the minimum size for an 80A cutout. It's only if you have a 100A fuse do you need 25mm2.

For using just the EV charger. If the load increases it needs 25mm wiring. There is evidence to suggest the wiring can't handle the load. 

There is nothing stopping you from upgrading the tails to 25mm2 if that gives you peace of mind but nothing in the wiring regs says it needs to be done because the size of the tails is related to the size of the cutout fuse not the loads you have on it.

If you have cause for concern then I strongly recommend that you ask a qualified electrician to inspect the installation for faults particularly in view of the fact that you have said that the cutout fuse blew and no root cause has been identified. The DNO are not responsible for any equipment after the fuse. OVO are not responsible for any equipment after the smart meter and 16mm2 tails are correctly sized for the 80A cutout fuse value you told me. The owner is responsible for anything after the smart meter.

I’m not intending to reply to any more posts here but if you want to come back on here with any findings then that would be useful for everybody.

Peter

Peter,

You clarifications have been confusing and add to the speculation. 

The 16mm wires from the main fuse to the smart meter are the responsibility of the energy supplier. There are no faults with any other wires from the smart meter to the circuit board. 

The wiring from the main fuse to the smart meter are heating up to the point where it's burning and the smell can be picked up throughout the house. This is the responsibility of the energy company and they should have changed these when they fitted the smart meter. There is no discussion here about anything else. 

OVO have even acknowledged this and offered a measley £10 as compensation. I didn't even ask for compensation. OVO are on notice so should there be any further instances of heated wires or blown fuses, I may have to take legal action under the Health and Safety regulations. 

Worth noting that meter tail upgrades aren’t included for free as part of a Smart Meter upgrade. That’s usually done as a separate job and is chargeable. AFAIK replacing faulty ones like-for-like is free though.

Legal action isn’t the right move for this - try https://ovoenergy.com/feedback for the Ombudsman if you get into a deadlock. By the way, the Health and Safety Executive will probably spit this one out if you try to refer it to them - they deal with workplace safety only and domestic matters like this one are out-of-scope for the HSE.

If memory serves… It’s also a matter that the Health and Safety at Work Act is more under criminal law than it is civil law anyway - you can’t do much with it yourself and you certainly can’t get compensation that way unless the HSE prosecutes. There’s no method for you to use that one as a customer on a domestic supply.

As we’ve said, you should consider the Energy Ombudsman instead if you get badly stuck.