Voltage drop for fp200

[Jamie Smith]

Hi,

Am running a radial power circuit in 4mm fp200 with a 20A rcbo but am a bit worried about the voltage drop. I have a 70M run clipped direct and by my calculations I will need to go to 6mm. I am using table 4d2 but don't know if there is a table for fp200.

 

[TJ Anderson]

What is your design current for the circuit?

 

[Darkwood]

As above... why FP200 as its not a common choice other than EM lighting and Fire Systems ...and what design current

 

[Jamie Smith]

The design current is 20a

 

[davesparks]

Get the data sheet from the manufacturer.

 

[telectrix]

you could perhaps use 4 core 2.5mm and parallel the conductors.

 

[Jamie Smith]

Just googled a manufacture they are giving a mv/a/m of 11 which is the value I used so will have to rethink or go to 6mm.

 

[Jonspark]

Find out the BS number of fp200, there's a section in the regs which will give you the correct table.

 

[Darkwood]

you could perhaps use 4 core 2.5mm and parallel the conductors.

What about Zs on this Tel...mg_smile: might work on short run but at 70m you will have earth serving doubled up L/N, this would worry me about it meeting Zs permitted values and not a route I'd want to take...

 

[davesparks]

Just googled a manufacture they are giving a mv/a/m of 11 which is the value I used so will have to rethink or go to 6mm.

A manufacturer? Do you mean the manufacturer? There is only prysmian who manufacture FP200 since FP is their brand name!

 

[davesparks]

Find out the BS number of fp200, there's a section in the regs which will give you the correct table.

As FP200 is a specific product from a specific manufacturer (prysmian) there won't be a table in the regs for it, the data sheet will be the place to look.

 

[Darkwood]

Jamie - can I enquire as to the nature of the circuit, seems a strange design current given the nature of its common uses, don't get me wrong not saying your using the wrong cable just curious thats all.

 

[Jamie Smith]

It for socket outlets in a large document warehouse.

 

[telectrix]

What about Zs on this Tel...mg_smile: might work on short run but at 70m you will have earth serving doubled up L/N, this would worry me about it meeting Zs permitted values and not a route I'd want to take...

oops. i didn't think that one out :ack2::ack2:

 

[Silly Sausage]

Find out the BS number of fp200, there's a section in the regs which will give you the correct table.

It's BS7629-1. Table 4A3 in BGB states to use 'Applicable Current Rating Table' 4D2.
So I assume Jamie can use 4D2B for his calcs.

 

[Jonspark]

http://www.fpcables.com/prysmian-fp-cables/prysmian-fp200-flex-cable/

 

[tazz]

Cable was manufactured by Pirelli, partner later by prysmain......max csa I`ve come across is 4mm, so 6mm may not be off the shelve cable, this may also help with mV/A/m ratings
http://www.ewholesaler.co.uk/PDFs/Prysmain_fp200_gold.pdf

 

[spark 68]

A couple of points to consider,

what is the likely loading on these S/Os ? in other words could you drop the Ib to say 16A ?

What about either making it two radials at the MCB or making it a ring ?

I am not sure if any of the above helps as obviously I don't know the layout, there are no problems, only solutions you have not thought of yet