hi to all, my first posting after viewing the forum for a month. please can you check ive got this right. putting a ring main in attick, the design current i have in mind is 3000 watt/13A ive picked a 16A B type MCB, the cable is 2.5mm it will be fed through conduit in plaster which derates it to 18.5A. Also a correction of o.94 [35 deg. c] because its hot up there, putting the rate of the cable at 17.39A. so i times this by 1.45 to get max short term loading for cable, which is 25.21A. The 16A MCB i have trips at 1.45A above its face value so that will be 23.2A which is below max short term load of cable. Have i got it right, if so B.A.S pat yourself on the back its your link i learnt this from.