Cable type ... current carrying capacity

[Paul_Williams]

I'm looking at an install of a double oven cooker ... 11.3kW maximum demand ... and rather than use 10mm T&E for the final connection I have been looking at the CCC tables in Appendix 4

Table 4E2A on page 368 (3rd Amend of 17th) states I should be able to use a cable with 6mm CSA conductors, but can anyone tell me what the name of the cable is as referred to in Table 4E2A.

The highest CCC that I have been able to get confirmed is for 6mm "TQ" which is to BS6500 and can handle up to 48A ... frustratingly close to the 50A circuit I need to install.

Doe anyone know what British Standard number cable that Table 4E2A is referring to???

Looks like I will have to fight with some 10mm T&E, but it would be nice to make the final connection in 6mm flex.

Any help would be greatly appreciated.

Regards,
Paul

 

[Octopus]

Who says the cooker has a maximum demand of 11.3 kw

have you applied diversity?

 

[telectrix]

as above. apply diversity. 6mm T/E on a 40A MCB if clipped direct, 32A if derated. cooker will never pull more than 25A except for very brief periods when all elements are on from cold.

 

[Octopus]

as above. apply diversity. 6mm T/E on a 40A MCB if clipped direct, 32A if derated. cooker will never pull more than 25A except for very brief periods when all elements are on from cold.

Tel - I would have preferred a response from the OP - you've given the game away now!

 

[telectrix]

soz, murdoch . i was bored with the same old question. it's on countless threads with the diversity calcs posted. now lets wait
for the next "supply to a shed" thread with "electrician's on holiday". :45:

 

[davesparks]

I'm looking at an install of a double oven cooker ... 11.3kW maximum demand ... and rather than use 10mm T&E for the final connection I have been looking at the CCC tables in Appendix 4

Table 4E2A on page 368 (3rd Amend of 17th) states I should be able to use a cable with 6mm CSA conductors, but can anyone tell me what the name of the cable is as referred to in Table 4E2A.

The highest CCC that I have been able to get confirmed is for 6mm "TQ" which is to BS6500 and can handle up to 48A ... frustratingly close to the 50A circuit I need to install.

Doe anyone know what British Standard number cable that Table 4E2A is referring to???

Looks like I will have to fight with some 10mm T&E, but it would be nice to make the final connection in 6mm flex.

Any help would be greatly appreciated.

Regards,
Paul

If the load is 11.3kW and the cable is rated at 48A then what's the problem?
Did you apply all the derailing factors before looking at the ccc tables, or did you just jump straight to the tables?

Table 4e2A doesn't apply to a specific cable, it applies to all cables with 90degree insulated and sheathed cables without armour. But you cannot use those ratings unless you terminations are capable of operating at 90degrees also, which they almost certainly won't be.

 

[Paul_Williams]

Ok, firstly my apologies for not replying sooner, like most of us I'm extremely busy.

Secondly there was limited information available and even the manufacturer had difficulty in locating the information I needed in order to provide the answer that would ultimately confirm what I was expecting and everyone here has jumped up and down about.

Thirdly, my apologies for asking a question with an obvious outcome that I was expecting but was looking for belts and braces solution should I not be able to prove a 32A supply would be acceptable.

Yes, it has been pointed out that the maximum demand would rarely be pulled, but due to limited information I was exploring options, better to over engineer a circuit and then drop the MCB capacity than do it the other way round.

I appreciate appropriate design calculations have to be made etc. etc. etc.

However, I was just a little bemused that when trying to identify the make/type/number of a cable that fit the description of Table 4E2A has not been possible ... so far as I have found.

Cable manufacturers were coming back with their cable being 85degree and not 90degree, CCC values differed wildly from any table, let alone 4E2A.

Maybe the CCC tables would be more useful if they specified BS numbers rather than a generic description ... yes the regs would get even more pages ... but imho ... it would be more useful.

Finally ... further apologies for asking a question that ... given more time than I had when I asked ... I may have been able to find in another thread ... but I am still sceptical anyone can quote a BS number for a cable type that matches that in Table 4E2A ... although I stand to be corrected.

 

[Midwest]

Ok, firstly my apologies for not replying sooner, like most of us I'm extremely busy.

Secondly there was limited information available and even the manufacturer had difficulty in locating the information I needed in order to provide the answer that would ultimately confirm what I was expecting and everyone here has jumped up and down about.

Thirdly, my apologies for asking a question with an obvious outcome that I was expecting but was looking for belts and braces solution should I not be able to prove a 32A supply would be acceptable.

Yes, it has been pointed out that the maximum demand would rarely be pulled, but due to limited information I was exploring options, better to over engineer a circuit and then drop the MCB capacity than do it the other way round.

I appreciate appropriate design calculations have to be made etc. etc. etc.

However, I was just a little bemused that when trying to identify the make/type/number of a cable that fit the description of Table 4E2A has not been possible ... so far as I have found.

Cable manufacturers were coming back with their cable being 85degree and not 90degree, CCC values differed wildly from any table, let alone 4E2A.

Maybe the CCC tables would be more useful if they specified BS numbers rather than a generic description ... yes the regs would get even more pages ... but imho ... it would be more useful.

Finally ... further apologies for asking a question that ... given more time than I had when I asked ... I may have been able to find in another thread ... but I am still sceptical anyone can quote a BS number for a cable type that matches that in Table 4E2A ... although I stand to be corrected.

My Hotpoint Range oven has a 5kw rating, but the manufacturers supply cable is a 1mm 3 core, testament to the time it takes to cook a Sunday lunch!

If there's a table in BS7671, you an guarantee someone at some time has made a cable for it, but it's more likely to be used in an industrial or commercial install, rather than a domestic kitchen.

The manufactures sometimes give guidance on supplies for their appliances, but often just give total heat input in kw.

Have you applied diversity as per OSG Table 1B or (I think) Table H2 GN1?

 

[Paul_Williams]

... ... ...
Have you applied diversity as per OSG Table 1B or (I think) Table H2 GN1?

Indeed I did, my initial issue was a lack of data from the manufacturer ... which has since been corrected.

However ... and as there is a strong possibility the property will become a B&B / Guest House ... Table H2 the second column relating to "Small shops ... business premises" is more fitting than the "... household ... dwellings ..." column ... the former requiring allowance for 100% of largest appliance plus 80% of second etc. ... so at the time of limited information and only having a maximum demand figure of 11.3kW my initial design had to at least allow for the potential of that amount of power to be drawn ... hence looking for a flex capable of handling 50A in free air or better still clipped direct ... it would have been easier to dress the cable in than 10mm T&E.

But ... all that is now history ... although the underlying question still remains as to where can you get a cable fitting Table 4E2A ??? ... and what type/BS number is it?

 

[Simonslimline]

Indeed I did, my initial issue was a lack of data from the manufacturer ... which has since been corrected.

However ... and as there is a strong possibility the property will become a B&B / Guest House ... Table H2 the second column relating to "Small shops ... business premises" is more fitting than the "... household ... dwellings ..." column ... the former requiring allowance for 100% of largest appliance plus 80% of second etc. ... so at the time of limited information and only having a maximum demand figure of 11.3kW my initial design had to at least allow for the potential of that amount of power to be drawn ... hence looking for a flex capable of handling 50A in free air or better still clipped direct ... it would have been easier to dress the cable in than 10mm T&E.

But ... all that is now history ... although the underlying question still remains as to where can you get a cable fitting Table 4E2A ??? ... and what type/BS number is it?

Try asking some manufactures perhaps.

 

[Spoon]

although the underlying question still remains as to where can you get a cable fitting Table 4E2A ??? ... and what type/BS number is it?

Please read the last paragraph in post 6. Does your equipment apply?

 

[davesparks]

Indeed I did, my initial issue was a lack of data from the manufacturer ... which has since been corrected.

However ... and as there is a strong possibility the property will become a B&B / Guest House ... Table H2 the second column relating to "Small shops ... business premises" is more fitting than the "... household ... dwellings ..." column ... the former requiring allowance for 100% of largest appliance plus 80% of second etc. ... so at the time of limited information and only having a maximum demand figure of 11.3kW my initial design had to at least allow for the potential of that amount of power to be drawn ... hence looking for a flex capable of handling 50A in free air or better still clipped direct ... it would have been easier to dress the cable in than 10mm T&E.

But ... all that is now history ... although the underlying question still remains as to where can you get a cable fitting Table 4E2A ??? ... and what type/BS number is it?

If you want flex then why are you looking at 4E2A, that is not the table for flex!

It does not refer to a specific bs number, it is a basic table for any unarmoured multi core with a 90degree operating temperature. Which will not be suitable for your application as the terminals you connect to will not be suitable for 90degree operation

 

[Spoon]

"these are not the cables you are looking for...."

 

[Paul_Williams]

Try asking some manufactures perhaps.

Been there ... two different wholesalers ... one with exceptionally strong links to a cable manufacturer ... neither could provide an answer ... closest was 85degrees but CCC around 38A ... another suggested TQ cable but that still only had a CCC of 48A.

But ... as I now have no need for a 6mm flex that can handle 50A ... well that's the end of that ... as they say.

 

[Paul_Williams]

Please read the last paragraph in post 6. Does your equipment apply?

I would hope so ... although the other fly in the ointment was trying to find a cooker connection point that is rated at 50A ... all that I have found to date are rated for 45A ... including Crabtree who I thought might be the ones to use.

 

[Paul_Williams]

If you want flex then why are you looking at 4E2A, that is not the table for flex!

It does not refer to a specific bs number, it is a basic table for any unarmoured multi core with a 90degree operating temperature. Which will not be suitable for your application as the terminals you connect to will not be suitable for 90degree operation

Doh!

Got side tracked with Note 3 beside the table ... "For cables having flexible conductors ...".

It's all a bit moot now then ...

Should have stayed in bed the other day ...

 

[Spoon]

I would hope so ... although the other fly in the ointment was trying to find a cooker connection point that is rated at 50A ... all that I have found to date are rated for 45A ... including Crabtree who I thought might be the ones to use.

Both post 6 and I was referring to the 90 deg C bit, not the amperage.

 

[Midwest]

Indeed I did, my initial issue was a lack of data from the manufacturer ... which has since been corrected.

However ... and as there is a strong possibility the property will become a B&B / Guest House ... Table H2 the second column relating to "Small shops ... business premises" is more fitting than the "... household ... dwellings ..." column ... the former requiring allowance for 100% of largest appliance plus 80% of second etc. ... so at the time of limited information and only having a maximum demand figure of 11.3kW my initial design had to at least allow for the potential of that amount of power to be drawn ... hence looking for a flex capable of handling 50A in free air or better still clipped direct ... it would have been easier to dress the cable in than 10mm T&E.

But ... all that is now history ... although the underlying question still remains as to where can you get a cable fitting Table 4E2A ??? ... and what type/BS number is it?

Haven't got a copy of GN1 myself. But isn't reference to the small shops & business to multiples of appliances, not one, re applying diversity? ....'all now history', are you not installing the appliance now?

 

[davesparks]

I would hope so ... although the other fly in the ointment was trying to find a cooker connection point that is rated at 50A ... all that I have found to date are rated for 45A ... including Crabtree who I thought might be the ones to use.

Your hopes will be in vain, there is no way any standard cooker plate will be rated for 90degree operation, they will be 70degree.

 

[telectrix]

could perhaps usea crabtree shower pull switch, 50A rating, but don't allow the cord to dangle in the stew. :77: