Sub main cable....minimum size????

Randyleprechaun

Hi,

Doing a job where there has to be a new sub main cable ran to a shed and then to another shed.

Is there now a rule that says cables feeding distribution boards have to be a minimum size. Someone mentioned to me that cable feeding any dist. board has to be minimum 16mm2. Doesn't sound right to me but I have been away from contracting for a few years.

Thanks

mikehammer67

no never heard anything like that

hufpc8w3adnk65

You will need too calculate the load of the 2 new installations and then you can calculate the size of the mains cable needed allowing for volt drop.

I mean if you were just putting a single pendant in each shed a 1.5 would prob do.but if it was for heavy duty farm machinery you might need 16's or bigger
Also keep in mind loads on installations hardly ever fall.they mostly get added too so when you calculate the size cable NEEDED it might be better too go too the next cable up in size too allow for additional work

*before someone says you can't use 1.5 or the like I haven't asked for the load or the distance of the run etc its just an example.

2011

Randyleprechaun wrote: »

Is there now a rule that says cables feeding distribution boards have to be a minimum size.

I have never heard of that.

Someone mentioned to me that cable feeding any dist. board has to be minimum 16mm2.

Makes no snese to me.

MrMac84 has stated, you need to look at the size of the load, lenght of run (to ensure that volt drop is not excessive), the protective device for the cable, the method of installation and any unusual ambient conditions that may affect the cable (e.g. abnormally high temperature). Once you have determined that you can select a suitable cable.

meercat

Randyleprechaun wrote: »

Someone mentioned to me that cable feeding any dist. board has to be minimum 16mm2.

Possibly mixing up the main cable to the meter which must be 16mm2