Plastic switch in external meter box

It is raining......

Tell me about it... At least the garden likes it and the water butts are filling up again.


I think we're generally on the same hymn sheet. So it seems that a 1-way DB (rather than a consumer unit) could be suitable for use by ordinary persons and comply with BS EN 61439-3 (not all will, but it's possible, if the manufacturer so chooses).


BS 7671's requirement for a main switch (or main circuit breaker) is that it is as near as practical to the origin of the installation (462.1.201) - which is just what you want if you cut off power to the entire premises for whatever reason - so I still say (unless one is provided by the DNO) the the switch on a switchfuse should be used in preference to one on a downstream CU - especially by ordinary persons who are less likely to understand the distinction and/or be aware exactly where the submain cable runs for example.

 

The consumer unit will have things that are in the off position if there is a fault or overload. That is consumer friendly, hence the moniker consumer unit for domestic [household] premises.

Now there I've got to differ - Consumer Unit got their name back in the day when rewireable fuses were still king - 'trip switches' (MCBs etc) are just the current fashion. We may well be returning to the situation were consumers may have to pull out and replace bits of their CUs to keep their installation in a serviceable condition if the current fad for SPDs (with replaceable cartridges) continues too.

 

Of course, a 1 way SPN distribution board is "similar switchgear"

So isn't a swithfuse just one example of a 1-way distribution board? They might (or might not) comply with different standards - but BS 7671 doesn't define things in terms of which standards they are constructed to meet, but in terms of their fundamental components and functionality. If it's "an assembly containing switching or protective devices ... associated with one or more outgoing circuits fed from one or more incoming circuits ... " BS 7671 seems to consider it a distribution board.

 

I do not think we should be condemning the use of KMFs in domestic installations. There are many, many thousands installed, they are compact and manufactured as a switchfuse, usually for a specific purpose where a distribution board is not suitable.

I wouldn't condemn an existing one - any more than I'd automatically condemn a plastic CU or rewireable fuse box - but for a new installation, presumably claiming to comply with the last requirements of BS 7671 and where more obviously compliant options exists, their use seems dubious to say the least. (I'm not sure what you mean about 'where a distribution board is not suitable'  - do you just mean fitting into small spaces?)


  - Andy.

It is raining......

Tell me about it... At least the garden likes it and the water butts are filling up again.


I think we're generally on the same hymn sheet. So it seems that a 1-way DB (rather than a consumer unit) could be suitable for use by ordinary persons and comply with BS EN 61439-3 (not all will, but it's possible, if the manufacturer so chooses).


BS 7671's requirement for a main switch (or main circuit breaker) is that it is as near as practical to the origin of the installation (462.1.201) - which is just what you want if you cut off power to the entire premises for whatever reason - so I still say (unless one is provided by the DNO) the the switch on a switchfuse should be used in preference to one on a downstream CU - especially by ordinary persons who are less likely to understand the distinction and/or be aware exactly where the submain cable runs for example.

 

The consumer unit will have things that are in the off position if there is a fault or overload. That is consumer friendly, hence the moniker consumer unit for domestic [household] premises.

Now there I've got to differ - Consumer Unit got their name back in the day when rewireable fuses were still king - 'trip switches' (MCBs etc) are just the current fashion. We may well be returning to the situation were consumers may have to pull out and replace bits of their CUs to keep their installation in a serviceable condition if the current fad for SPDs (with replaceable cartridges) continues too.

 

Of course, a 1 way SPN distribution board is "similar switchgear"

So isn't a swithfuse just one example of a 1-way distribution board? They might (or might not) comply with different standards - but BS 7671 doesn't define things in terms of which standards they are constructed to meet, but in terms of their fundamental components and functionality. If it's "an assembly containing switching or protective devices ... associated with one or more outgoing circuits fed from one or more incoming circuits ... " BS 7671 seems to consider it a distribution board.

 

I do not think we should be condemning the use of KMFs in domestic installations. There are many, many thousands installed, they are compact and manufactured as a switchfuse, usually for a specific purpose where a distribution board is not suitable.

I wouldn't condemn an existing one - any more than I'd automatically condemn a plastic CU or rewireable fuse box - but for a new installation, presumably claiming to comply with the last requirements of BS 7671 and where more obviously compliant options exists, their use seems dubious to say the least. (I'm not sure what you mean about 'where a distribution board is not suitable'  - do you just mean fitting into small spaces?)


  - Andy.