How to activate isolation on this smart meter.

[LeeJC]

Can someone advise how to set the internal contractor to open on this meter please.
I’ve checked all the literature and it tells me that it can be done but not how to do it. It’s a tri state device seemingly (Open/primed/closed)

Any help appreciated.
Cheers
Lee

 

[LeeJC]

Never mind........... I'll get the supplier out to fit an isolator.

 

[ericmark]

You can't, only the supplier can turn off your supply, even the fire brigade can't open the isolator, which raises the question why fit the isolator to start with, if only use is so supplier can remove supply remotely for non payment?

This is one of the reasons why people don't want smart meters, mistakes have happened, and the wrong person had their supply cut off, so why take the risk?

 

[LeeJC]

I’d rather have a standard meter but it’s a property I’m buying and it’s already installed.
Guess I’ll pay the £140 for an isolator to be fitted.

 

[fourtytwo]

Umm, surely there is an isolator in the cu where the other end of the meter tails go ?
I don't think you can get an isolator between the board fuse & smartmeter otherwise the latter might loose it's marbles!

 

[oldbutnotdead]

Even if you could operate the contactor I wouldn't fancy working on a system isolated just on it.

 

[LeeJC]

Evening both.
Yeah there is an isolator in the CU, but it's a 30 year old Hager board with Cartridge style fuses which really needs an update so a full Hager RCBO board is going in. It's not only being replaced due to age it's being replaced due to additional circuits being required for a partial garage conversion (into office) so +1 Radial and +1 lighting.
Need to replace/add sockets to the installed ring final circuits and intend to separate the Kitchen from those.

I'll get OVO to put a double pole isolator between the meter and CU as currently installed. I did a bit more reading/thinking and the meter isolation is on the line only, so no I wouldn't trust it at all.................. it's also software controlled. And in the industry I'm in you can't have 'safety critical software'.......................

 

[Taylortwocities]

Isolation by logic control is not permitted.

 

[LeeJC]

Isolation by logic control is not permitted.

Can you expand on that a little?
Isn't this exactly the technology that's built into smart meters? Or is whatever regulation that calls that up not applicable to the supply side?
Applying a bit of consideration to things, in the event the provider disconnects you then your entire installation becomes unsafe due to it being in an unknown or none locally controlled state.
E.G. Dave decides he's going off grid, tells supplier to disconnect his supply, supplier carries out request. His mate Pete comes round to start working on cabling up batteries/turbines/solar whatever and Sheila at the supplier is having a bad morning, inadvertently reenables the supply while Pete is pulling the tails out of the CU.

 

[Taylortwocities]

Can you expand on that a little?

Quite simply, I suggest you read regulation 537.2.

SAFE isolation is always, always by a mechanical means. Once a circuit has been determined as being safely isolated, it is locked off by old fashioned things like padlocks.
Unfortunately the regs isn't up to date in modern techniques. In summary it says (see last line)

Isolation: 537.2​

Every circuit / installation must be provided with a method of isolation from the supply. This isolation device should also be provided with a method to prevent unintentional or inadvertent reinstating (usually lockable).

In a TN-S or TN-C-S system it is not necessary to isolate / switch the neutral conductor providing that it is ‘reliably’ connected to Earth on the distributors incoming supply side.

Semiconductor devices can not be used as isolating devices.

For me the Internet has many billion semiconductor devices in it. Not to mention, as you highlight, being prepared to risk your life in the hands of a hung-over electricity supply person working from home to get it right.

Isolate the circuit. Lock it off and put the key in your pocket.

 

[LeeJC]

Quite simply, I suggest you read regulation 537.2.

SAFE isolation is always, always by a mechanical means. Once a circuit has been determined as being safely isolated, it is locked off by old fashioned things like padlocks.
Unfortunately the regs isn't up to date in modern techniques. In summary it says (see last line)

Isolation: 537.2​

Every circuit / installation must be provided with a method of isolation from the supply. This isolation device should also be provided with a method to prevent unintentional or inadvertent reinstating (usually lockable).

In a TN-S or TN-C-S system it is not necessary to isolate / switch the neutral conductor providing that it is ‘reliably’ connected to Earth on the distributors incoming supply side.

Semiconductor devices can not be used as isolating devices.

For me the Internet has many billion semiconductor devices in it. Not to mention, as you highlight, being prepared to risk your life in the hands of a hung-over electricity supply person working from home to get it right.

Isolate the circuit. Lock it off and put the key in your pocket.

I agree with the regulation entirely and I’m fiercely agreeing with you that physical isolation is the only truly safe means of doing this.
What occurs to me is that the era of smart meters has introduced a situation where the supplier can deactivate a circuit using software, such a circuit at anything but the cutout fuse would give the appearance of being inert.
So with a smart meter and no isolator installed then the only means to mechanically render and installation truly inert is to remove the cut out fuse.
Suppliers seem to suggest that the tails become the responsibility of the electrician at point of meter exit.
Doesn’t this suggest that before doing any activities around the CU requires the cutout fuse to be removed? And aren’t we in a situation where this is quite rightly advised against?

 

[LeeJC]

I was going to put something about the safest way to remove a cut out fuse is under no load conditions, but smart/stupid meters are still going to present a minor load anyway, so it’s not a unique smart meter problem.
Although removing the cut out does risk the smart meter firmware and possibly trigger a tamper alarm with the supplier. Seems OVO have put a 72 hour limit on disconnections for work. Now why might that limit be necessary? Battery back up??

Appears to me that double pole isolators after a smart meter should be mandatory and the responsibility of the supplier, and that the outgoing tail connection from the isolator should be the point of responsibility transfer to the electrician.

 

[Taylortwocities]

I remember hearing that, in the design brief for the smart meter, an isolator switch was included. Some of the later digital non-smart meters had such a thing.
This feature was removed as part of the inevitable cost-cutting process.

Note: if you remove the supply to a smart meter I believe that the meter will automatically report what you have done. The meter police will probably come and find out if you gave started up a wacky backy farm in your attic.

 

[JohnW2]

I agree with the regulation entirely and I’m fiercely agreeing with you that physical isolation is the only truly safe means of doing this.

I'm pleased to hear that. However, in your initial post you were asking how you could operate the ('software controlled') switch/contactor within the meter, which seemed to imply that you were thinking of using it for isolation. Was that not the case?

Kind Regards, John

 

[JohnW2]

I remember hearing that, in the design brief for the smart meter, an isolator switch was included. Some of the later digital non-smart meters had such a thing.
This feature was removed as part of the inevitable cost-cutting process.

My daughter's ('dumb') meter still has a built-in ('mechanical')isolator, which has proved very useful, and seems an obvious thing to do - but I've seen very few meters that have that.

Kind Regards, John