Strange off peak meter setup??

[westie101]

Sorry guys - I will go to my grave being in no doubt whatsoever that work like that does not count as good workmanship and therefore does not comply with the Wiring Regulations.

Yep it looks horrible but the Supplier will argue that it does not form part of the consumer's installation so BS7671 does not apply!

The reality is that it is in the metering cabinet, as it is connected directly to the meter not legally accessable to the customer to perform any work on it.
In reality if a fault occured the cable, as such, would probably disintigrate without blowing the fuse i.e. in some ways the cable is the fuse.

In reality it should have been wired as a spur from the on-peak CU

 

[ban-all-sheds]

I'm not too sure what you (or anyone else) is thinking of as an alternative - one could not connect 16mm² conductors to an FCU.

I'll give you an alternative.

1 x DP or 2 x SP Henley blocks.

4 more lengths of meter tails.

A small CU (even just a 2-module wide enclosure with an RCBO).


Always assuming that you want the spur to originate in the meter cabinet - I can't work out why it couldn't have been taken from an existing final circuit elsewhere.

But then I also can't work out how that meter works with a dual-tariff supply, as i has neither two displays nor (as far as I can see) any control to make it show a particular reading.

 

[ban-all-sheds]

Yep it looks horrible but the Supplier will argue that it does not form part of the consumer's installation so BS7671 does not apply!

I thought that the consumer's installation started after the meter.

 

[westie101]

But then I also can't work out how that meter works with a dual-tariff supply, as i has neither two displays nor (as far as I can see) any control to make it show a particular reading

Button in top left hand corner.

I thought that the consumer's installation started after the meter.

Generally yes, except (certainly) when there is an isolator fitted.
It could be argued that this applies to this circuit!!

It's true to say that out here ther interpretations can get difficult

 

[plugwash]

There are several things that concern me about this setup.

1: the switches on FCUs are not great as isolation devices, they are easilly knocked and can't easilly be locked off. On some FCUs it's possible to padlock the fuse carrier out or to remove the fuse carrier completely but that only provides single pole isolation.
2: FCUs are not designed to have the output connections worked on while the input connections are still live. That's not good for a device that is acting as a demarcation point.
3: there is no evidence of earthing for this off-peak supply. Maybe earthing is picked up at the boiler end but I certainly wouldn't consider "borrowed earths" a good practice.
4: there are single insulated cores exposed (albiet in a location where the real risk is minimal).
5: the off peak cables are loose and unsupported despite going to connections without any form of cable restraint.

Overall I wouldn't class the setup as immediately dangerous but I would certainly consider it sub-standard.

I would be much happier with a proper switchfuse or mini-cu or a DP MCB in a two-module box with double insulated tails connecting it to the meter.

 

[plugwash]

Always assuming that you want the spur to originate in the meter cabinet - I can't work out why it couldn't have been taken from an existing final circuit elsewhere.

My reading of the original post is it's a control signal to tell their electric boiler when it's off-peak time hence it can't be taken from the main CU as the main CU is connected to a 24/7 supply.

 

[ban-all-sheds]

Button in top left hand corner.

OK.

I enlarged the photo and that looked like an optical port to me.

 

[ban-all-sheds]

My reading of the original post is it's a control signal to tell their electric boiler when it's off-peak time hence it can't be taken from the main CU as the main CU is connected to a 24/7 supply.

So is that FCU.

There is only 1 supply, and it is live 24x7. Some loads, such as the heating are (one hopes, but the abilities of the installer make me unsure that he had sufficient clues) controlled by timeswitches so that they only fire up when the supply is being charged at a cheap rate.

You just have to hope that your timeswitch agrees with the supplier's one...

http://www.consumeractiongroup.co.u...roblem]-on-nightrate!!-Meter-watchers-needed.

 

[ericmark]

As stated likely does not need to comply with BS7671 but I remember when I got pulled by the HSE for leaving a key in a panel where there was no problem with ordinary persons having access which could be removed and placed in a panel where only electricians should have had access.

So if the key is given to the house holder to read the meter then there is assess by ordinary persons. Likely however even with single insulation there is no danger.

But the lack of earth is something else. Clearly no earth to the FCU so even if there is an earth wire in the cable out of the FCU then it is unlikely under fault conditions it with cause the fuse to rupture.

We of course can't see where that cable goes to but should some one have switched off the consumer unit and be doing tests on it there is not guarantee the earth will be connected it would be so easy to include an earth just seems strange it was not included.

I accept the rules say "isolate else where" so when doing any work on a consumer unit the DNO fuse or DNO isolator needs drawing or switching off following HSE rules. But we all know we don't break the seal every time we go into a consumer unit so it just seems strange not to include an earth cable.

 

[plugwash]

There is only 1 supply, and it is live 24x7.

What makes you think that?

My understanding is that meters that support dual rate have a switched output terminal which in a "normal" off-peak electrically heated house is connected to a second CU which runs the storage heaters and nighttime immersion.

You just have to hope that your timeswitch agrees with the supplier's one...

I would think that would be the whole reason for using switched supply from the supplier as a control signal rather than using your own timers.

 

[ban-all-sheds]

There is only 1 supply, and it is live 24x7.

What makes you think that?

The fact that it only has 1 output.

My understanding is that meters that support dual rate have a switched output terminal which in a "normal" off-peak electrically heated house is connected to a second CU which runs the storage heaters and nighttime immersion.

Can you see 2 outputs?

 

[JohnW2]

1 x DP or 2 x SP Henley blocks. ... 4 more lengths of meter tails. ... A small CU (even just a 2-module wide enclosure with an RCBO). ... Always assuming that you want the spur to originate in the meter cabinet - I can't work out why it couldn't have been taken from an existing final circuit elsewhere.

I'm rather confused by your view about what's going on. By proposing that the outgoing meter tails be split, you are presumably assuming the at 1.5mm² cable originates from the same place (electrically) as the main tails, but that would make no functional sense. There is only one pair of 'main tails' coming out of the meter, so they must always be energised, the meter (assuming that it is dual tariff) merely switching between tariff counters. A supply derived from those main tails therefore would not provide a peak/off-peak indication signal. The only thing which would really make any sense would be if that 1.5mm² cables comes from a (maybe just 'signal') output terminal of the meter other than the ones to which the main tails are connected. What do you think?

If I'm right, then (contrary to what you have suggested) there would be nowhere other than the meter from which that 'signal' feed could be derived.

Kind Regards, John

 

[westie101]

Looking closely at the photo, the live core of T&E is probably connected to the OP load terminal and just provides a signal

Regarding the lack of OP load tail.
I have an E7 connection but no E7 heating, it was common to install E& and take advantage of the cheaper rates to operate washers, tumble dryers and other large loads overnight.
Overall it did and can save money

 

[plugwash]

Can you see 2 outputs?

Well the terminals are hidden behind a cover so it's hard to tell for sure but it doesn't look like the T&E and the tails are in the same terminals to me.

 

[JohnW2]

Well the terminals are hidden behind a cover so it's hard to tell for sure but it doesn't look like the T&E and the tails are in the same terminals to me.

As I've just written, it would really make no functional sense if that T+E were connected to the same L meter terminal as the main (and only) outgoing L tail - since it would then be constantly energised and could not provide the required 'signal'.

Kind Regards, John