0.75mm Flex into 6A MCB

[uksparks]

Hi,

As per title, how would you feel about connecting a few garage lights onto some 0.75mm flex straight into the 6A MCB, ignore switching, just that its 0.75mm.

I have to say I normally go via a FCU but in this occasion I don't feel I need to as its in the garage with a 6A MCB I can come off.

referring to table 4F3A on page 378 it states 0.75 can take 6A.

id say I'm good to go, I k ow I'm probably stating the obvious but it's not something I usually do, hooking such a small co doctor up to an MCB.

reason for it being small is due to the fact I'm using 3 core and earth flex so I can use the switched output on the lights so they Interconnect on PIR.

 

[uksparks]

They should be available from most DB manufacturers, they won't be available for ranges exclusively intended for CUs though.

Can you use them for general/standard circuits? I see no reason why not, but undoubtedly someone will be able to come up with a reason why not.

7.5A was a reasonably common size once upon a time. I've seen a lot of 3871 MCBs in this size.

I love a 25A MCB myself. Not very common but so useful.

yes it gives just that bit more in a 2.5mm radial instead of a 20A, I think I should get myself a few!

 

[Leesparkykent]

yes it gives just that bit more in a 2.5mm radial instead of a 20A, I think I should get myself a few!

Just about if it's clipped direct.

 

[Pete999]

Hi,

As per title, how would you feel about connecting a few garage lights onto some 0.75mm flex straight into the 6A MCB, ignore switching, just that its 0.75mm.

I have to say I normally go via a FCU but in this occasion I don't feel I need to as its in the garage with a 6A MCB I can come off.

referring to table 4F3A on page 378 it states 0.75 can take 6A.

id say I'm good to go, I k ow I'm probably stating the obvious but it's not something I usually do, hooking such a small co doctor up to an MCB.

reason for it being small is due to the fact I'm using 3 core and earth flex so I can use the switched output on the lights so they Interconnect on PIR.

Old school I know, but flex for fixed wiring? tut tut

 

[cprfenom]

I cant see why using 1.0 or 1.5mm flex to wire downlights in would be an issue. Most of the clamps seem to be designed for round cable also. You also seem to see lots of companies doing full rewires in flex.

 

[Pete999]

I cant see why using 1.0 or 1.5mm flex to wire downlights in would be an issue. Most of the clamps seem to be designed for round cable also. You also seem to see lots of companies doing full rewires in flex.

D oes the customer have to provide feed for their horses, rewires in flex, what is this trade coming to? I for one am out of this conversation.

 

[cprfenom]

I cant really see the advantage of doing that. I cant see a valid trade off between time and cost. Also terminating flex is harder than solid core.

Sorry for taking the thread off topic.

 

[Sintra]

Old school I know, but flex for fixed wiring? tut tut

D oes the customer have to provide feed for their horses, rewires in flex, what is this trade coming to? I for one am out of this conversation.

Pete, you might find this hard to believe but as you know I have been involved in rewires of the prestigious overseas buildings you used to frequent. These as you know are designed in the UK and installed to UK spec. Within the last 5 years the trend has changed and we have been forced to used flex for all of the fixed wiring in some of these properties. I think it's down to the individual designer as it's not a blanket thing across all properties.

 

[Leesparkykent]

I've never seen a full rewire in flex lol.

 

[Darkwood]

Old school I know, but flex for fixed wiring? tut tut

It certainly is an old school thinking, flex holds similar electrical properties as T&E but the issue has always been termination, when screw terminals were really the norm with no alternative many simply terminated without ferrule and this has over the years been a big factor in building fires, now the call to ensure correct termination is greater and people are more aware due to sites like this and it been discussed more about correct crimping and/or suitable connections for fine wire. There is no reason flex cannot be used, as we all know it has its advantages and disadvantages against standard methods of wiring but we should no longer condone it as long as the cable calcs are fine.

 

[Pete999]

Pete, you might find this hard to believe but as you know I have been involved in rewires of the prestigious overseas buildings you used to frequent. These as you know are designed in the UK and installed to UK spec. Within the last 5 years the trend has changed and we have been forced to used flex for all of the fixed wiring in some of these properties. I think it's down to the individual designer as it's not a blanket thing across all properties.

Thanks mate, still riles me does that, best I'm out of it now. rewires that is.

 

[uksparks]

And here is the finished article... I like these lights, they look nice and work well. I did it in three core and earth 1mm in the end, fitted an IP66 switch to override on the outside too just the other side of the drain pipe.

 

[Dave OCD]

Looking good, I use loads of those too, nice how you connect to the base [very easy] then the main fitting just plugs in and secures with 2 small screws.

 

[Dave OCD]

Thinking about it assuming all 3 come on when any of the PIR's are activated- couldn't the 'middle' one have been a slave unit without P.I.R ? That would have saved a few quid.:smiley2:

 

[uksparks]

It's the ASD light as you probably guessed, I really enjoy fitting them as they are so easy, plus you have the switched live terminal to hook them together.

fit the difference in price I just fitted three with PIRs... It's only a few quid more.

 

[Dave OCD]

Yeah they're great, and totally made from polycarbonate so no falling to bits within a couple of years like the horrible cheap painted metal lanterns.