night tariff meter change to standard tariff

[Colin188]

I've been asked by a customer to remove four nights storage units and replace the switched fused spurs with single 13amp sockets.
Each unit is fed from a dedicated consumer unit supplied from a economy 7 meter.
I need to remove the meter tails from the night tariff meter and connect the consumer unit that feeds the replaced spurs through the Henley blocks that feeds the main consumer unit.
Is this practice reportable under part P and does the electrical supply companies need be informed.

 

[Andy-1960]

If the off peak tariff is no longer being used I would recommend talking to the energy supplier as usually the normal tariff is more expensive when a split tariff is being used. So they may want to change the meter.

If you need to remove the tails from the off peak tariff meter this will mean cutting the seals and if they choose to change the meter they will know what you have done.

As far as Part P goes I think yes it is notifiable as it is a major modification.

 

[westward10]

Are you going to provide a single point of isolation for both boards.

 

[snowhead]

Ist point of contact for the Customer is the Energy supplier.
They need to know and agree to drop the E7 charges.

It may be that they'll leave the existing meter in and charge the same rate for both tariffs for now, then no tail shifting required.
Or if they want to change the meter then they'll have to move the tails.

 

[Colin188]

Are you going to provide a single point of isolation for both boards.

As the meter tails would be under 3 metres I did not think that single point isolation was needed as the incoming house service fuse would suffice

 

[westward10]

The householder should have a single point of isolation, the service fuse will not suffice.

 

[7029 dave]

The energy provider should do the conversion. It is their equipment, when I change from E7 to standard, e7 tails are disconnected put in blocks, meter changed to single tariff, then its over to Electrician to reconnect to 24hr supply.

 

[Colin188]

The householder should have a single point of isolation, the service fuse will not suffice.

Have not enough room to install single point isolation.
Cannot find any regulation that covers this.
Would signage surface

 

[westward10]

Have not enough room to install single point isolation.
Cannot find any regulation that covers this.
Would signage surface

Reg 537.1.4, signage may apply to large commercial/industrial sites where multiple supplies are present but see no excuse on a domestic. Will the sockets have rcd protection.

 

[Octopus]

The householder should have a single point of isolation, the service fuse will not suffice.

Another of the ill thought out changes to the regs..... If you don't have the knowledge to turn off two switches rather than one, words fail me

 

[Deleted member 26818]

"537.1.4 A main linked switch or linked circuit-breaker shall be provided as near as practicable to the origin of every installation as a means of switching the supply on load and as a means of isolation.
A main switch intended for operation by ordinary persons, e.g. of a household or similar installation, shall interrupt both live conductors of a single-phase supply."

 

[Deleted member 26818]

This requirement is not new, been around for decades.

 

[Colin188]

"537.1.4 A main linked switch or linked circuit-breaker shall be provided as near as practicable to the origin of every installation as a means of switching the supply on load and as a means of isolation.
A main switch intended for operation by ordinary persons, e.g. of a household or similar installation, shall interrupt both live conductors of a single-phase supply."

Reg 537.1.4, signage may apply to large commercial/industrial sites where multiple supplies are present but see no excuse on a domestic. Will the sockets have rcd protection.

No they will not as i will not be changing the consumer unit.
The only other way i can see around this is to supply the old ecconomy 7 consumer unit from a 32 amp mcb on the main consumer unit with 6mm t&e which has a double pole switch disconnector and a 30mA rcd and this should cover all the regs?

 

[Deleted member 26818]

No they will not as i will not be changing the consumer unit.

???

 

[westward10]

You are going to have to provide additional rcd protection because you are creating new socket outlets. The best way to do this is to replace both boards with a single unit.

 

[Deleted member 26818]

What you need to do, is get the DNO to remove the off peak meter and to have ready a dual isolator for them to connect the meter tails into.
Then you can connect both CUs into the dual isolator.
As Westward10 says, you will need to provide RCD protection for the sockets.

 

[westward10]

What you need to do, is get the DNO to remove the off peak meter and to have ready a dual isolator for them to connect the meter tails into.
Then you can connect both CUs into the dual isolator.
As Westward10 says, you will need to provide RCD protection for the sockets.

Problem here he is missing rcd protection with the existing board, suppose you could fit rcd sockets.

 

[Deleted member 26818]

I would assume the OP has already figured out how to provide the required RCD protection.

 

[7029 dave]

The op has not mentioned, whether the E7 CU has rcd protection.?It already may have.

 

[westward10]

I would assume the OP has already figured out how to provide the required RCD protection.

Not according to his reply in #13

 

[Colin188]

What you need to do, is get the DNO to remove the off peak meter and to have ready a dual isolator for them to connect the meter tails into.
Then you can connect both CUs into the dual isolator.
As Westward10 says, you will need to provide RCD protection for the sockets.

i think it would be easier if i can take the four 2.5mm t&e radial feeds from the economy 7 consumer unit and connect them to the main tariff consumer unit which has split load rcd and install 16 amp mcb for each radial circuit. this should cover all bases.

 

[westward10]

The op has not mentioned, whether the E7 CU has rcd protection.?It already may have.

It has not.

 

[westward10]

i think it would be easier if i can take the four 2.5mm t&e radial feeds from the economy 7 consumer unit and connect them to the main tariff consumer unit which has split load rcd and install 16 amp mcb for each radial circuit. this should cover all bases.

Yes if there are adequate spare ways.

 

[davesparks]

Another of the ill thought out changes to the regs..... If you don't have the knowledge to turn off two switches rather than one, words fail me

Changes? The requirement for a single main switch was in the first edition!

 

[Colin188]

Yes if there are adequate spare ways.

I should be able to take two spur circuits off each of the two 32amp ring main mcb in the consumer unit. The sockets will be single socket outlets.

 

[westward10]

I should be able to take two spur circuits off each of the two 32amp ring main mcb in the consumer unit. The sockets will be single socket outlets.

Not sure that is the greatest idea, four 2.5 conductors at one mcb.

 

[Deleted member 26818]

Lol.
I read it as being one spur from each RFC taken from the relevant MCB, so only 3 conductors?

 

[westward10]

He has four radials and two ring finals?

 

[Deleted member 26818]

Yes, I just assumed the OP would spur a single socket of each MCB and use a couple of spare ways for the other two.

 

[Colin188]

"537.1.4 A main linked switch or linked circuit-breaker shall be provided as near as practicable to the origin of every installation as a means of switching the supply on load and as a means of isolation.
A main switch intended for operation by ordinary persons, e.g. of a household or similar installation, shall interrupt both live conductors of a single-phase supply."

Just a reference on this.Hello,
Please offer clarification as to whether regulation 537.1.4, or in fact any other regulation prohibits the common practice of splitting the mains supply from the meter, via Henley block to 2 or more CCU's? Each CCU in its own right has DP isolation. Does this regulation, or in fact any other regulation insist on a suitably rated DP isolator to be placed in line with the meter tails offering a single point of isolation for the 2 or more separate CCU's.

Note, an assessment of general characteristics would additionally be conducted to ensure compliance.

This question needs a written answer as evidence to address the questions within my immediate circles, that the above practice of splitting the mains supply via Henley block doesn't comply with the Regs and specifically 537.1.4.

Thank you.

Regards,

NICEIC response:

Wango
Please accept our apologies for the delay in replying to your query.
I can confirm that such practice is allowed under BS 7671. Attention should also be given to 537.2.1.3 & 537.2.2.6
I hope this helps.
Regards
**** ***** BSc MIET IEng
Area Engineer

 

[westward10]

I totally disagree with this for a domestic installation, can they confirm where in BS7671 this is noted. I suspect they are implying that by doing this you are creating two installations each of which having a single point of isolation making Reg 537.1.4 a farce.

 

[snowhead]

As the installation is now and any other with split off peak, there is no single point of isolation other than the 2 C.Us being adjacent to each other.

 

[westward10]

Use a four pole isolator.

 

[Deleted member 26818]

As the installation is now and any other with split off peak, there is no single point of isolation other than the 2 C.Us being adjacent to each other.

Two installations.
The origin of an installation is and always has been, the customer connection point (usually at the meter).
With split tariffs there is either two meters, each supplying a separate installation or a single meter with two connection points, with each connection point supplying a separate installation.
BS7671 allows for more than one installation in a building.

The NICEIC (despite the fact that the respondent is a member of the IET), loves to make up their own regulations or make their own interpretation.

 

[Colin188]

I totally disagree with this for a domestic installation, can they confirm where in BS7671 this is noted. I suspect they are implying that by doing this you are creating two installations each of which having a single point of isolation making Reg 537.1.4 a farce.

I would assume that the double pole switch disconnections in each consumer unit would satisfy this as both consumer units are next to each other.

 

[westward10]

I would assume that the double pole switch disconnections in each consumer unit would satisfy this as both consumer units are next to each other.

I disagree but that aside how will you provide additional rcd protection.

 

[Deleted member 26818]

I would assume that the double pole switch disconnections in each consumer unit would satisfy this as both consumer units are next to each other.

No.
They comply at present because they are two separate installations, both controlled by a single point of isolation.

 

[Deleted member 26818]

The purpose of the single point of isolation, is so in the event of an emergency, the installation can be switched off easily.

 

[Colin188]

The purpose of the single point of isolation, is so in the event of an emergency, the installation can be switched off easily.

So with correct warning identification on each consumer unit this would meet requirements. If one cu was a shower cu then mark as shower, if next was garage cu then mark as garage, and the final cu would be marked main distribution i.e sockets/lighting making correct for emergency/maintenace isolation for the domestic consumer.

 

[Deleted member 26818]

That would be for you to decide.
In the event of a fire with smoke billowing around, would what you suggest be easy for a fire fighter who doesn't know the property, to isolate?

 

[mattg4321]

Having to switch off at 2 consumer units rather than 1 would be the least of my worries were I said firefighter.

The amount of s*** most people keep in the way of getting to the consumer unit(s) would be worry numero uno.

If firefighters in this situation were of such importance surely regulations should specify that where possible (certainly in new builds) DP isolation to be provided at external meter box.

 

[Colin188]

Having to switch off at 2 consumer units rather than 1 would be the least of my worries were I said firefighter.

The amount of s*** most people keep in the way of getting to the consumer unit(s) would be worry numero uno.

If firefighters in this situation were of such importance surely regulations should specify that where possible (certainly in new builds) DP isolation to be provided at external meter box.

Totally agree . Lets have a Red firemans switch external to each property to overcome this worry. Could be in the 18th edition! Would have solved all this

 

[Deleted member 26818]

Strangely enough, the requirement for a fireman's switch has been discussed.
At present existing devices do not have a sufficiently high enough rating for the majority of installations.
Then there are further considerations.
Can it be tamper proof, can it be installed so as to isolate p.v. systems, how would it work with UPS systems, should it be installed as part of the distributer's equipment, what about buildings with multiple supplies, etc?