S
Ste69
Bit nervous about putting this on the open board, normally stick to the trainee section.
Hope i can get some help. I have recently qualified so dont be to harsh if im not 100% correct.
Ive been asked to help an older spark to pull a a 3 phase SWA cable. Ive been asked to design the circuit i,e correct size cable and protective device.
This is the info i have. We are using a 3 phase 4 core SWA cable, we are coming from the main DB, run of 35 metres to a kitchen, into another DB (this is going to be used for the new kitchen equipment) the maximum load will be 10kw. We are clipping direct to walls and it will not be bunched with any other cables. I will be getting more info tomorrow.
This is my thought path so far.
Ib=P/1.732xVl, Ib=10000/1.732x400, Ib=14.43A (unsure if i should use correction factor cg? to get In, as there are 4 cores in the cable is this classed as bunched or is it classed as one cabel? sorry if that is dumb) i decided not to use for now. so using Ib. ( i also realise if i were designing a bigger circuit i would need to use power factor?)
i then looked in my on-site guide, table F5 on page 147(green), Ref method c lets me use 1.5mm cable. (this seems way to small?)
next i worked out the volt drop mvxibxl/1000, so looked in the on site guide, table F4 on page 146 i used 25 mv/a/m, so 25x14.43x35/1000 = VD 12.62 so it is good to go as it is under 20VD.
conclusion is i could use 1.5mm cable and a 16 amp 3 phase MCB type C? ( i would think using a 2.5mm cable with 16 amp mcb may be better as the vold drop would be lowered by quite a bit or even 2.5mm with a 20 amp mcb)
This is as far as i have got not knowing more info. Am I on the correct path here? any advice? very much appreciated
I am not going to do anything with this, this is not my job, i am just helping but i want to know how to do this for future. What info should i ask for tomorrow?
any constructive criticism welcome! any crap just stay oot! cheers.
I really need to buy the new regs!
Hope i can get some help. I have recently qualified so dont be to harsh if im not 100% correct.
Ive been asked to help an older spark to pull a a 3 phase SWA cable. Ive been asked to design the circuit i,e correct size cable and protective device.
This is the info i have. We are using a 3 phase 4 core SWA cable, we are coming from the main DB, run of 35 metres to a kitchen, into another DB (this is going to be used for the new kitchen equipment) the maximum load will be 10kw. We are clipping direct to walls and it will not be bunched with any other cables. I will be getting more info tomorrow.
This is my thought path so far.
Ib=P/1.732xVl, Ib=10000/1.732x400, Ib=14.43A (unsure if i should use correction factor cg? to get In, as there are 4 cores in the cable is this classed as bunched or is it classed as one cabel? sorry if that is dumb) i decided not to use for now. so using Ib. ( i also realise if i were designing a bigger circuit i would need to use power factor?)
i then looked in my on-site guide, table F5 on page 147(green), Ref method c lets me use 1.5mm cable. (this seems way to small?)
next i worked out the volt drop mvxibxl/1000, so looked in the on site guide, table F4 on page 146 i used 25 mv/a/m, so 25x14.43x35/1000 = VD 12.62 so it is good to go as it is under 20VD.
conclusion is i could use 1.5mm cable and a 16 amp 3 phase MCB type C? ( i would think using a 2.5mm cable with 16 amp mcb may be better as the vold drop would be lowered by quite a bit or even 2.5mm with a 20 amp mcb)
This is as far as i have got not knowing more info. Am I on the correct path here? any advice? very much appreciated
I am not going to do anything with this, this is not my job, i am just helping but i want to know how to do this for future. What info should i ask for tomorrow?
any constructive criticism welcome! any crap just stay oot! cheers.
I really need to buy the new regs!