K
kai
According to Tables in the Brown copy of BS7671:2001, a 13amp BS1362 cartridge fuse has a max allowable earth resistance of 2.53.ohms for 0.4.sec disconnection...BUT a B16 amp MCB has a max earth loop resistance of 3.00.ohms for 0.4.sec disconnection.
It seems that the lower rated device needs a SMALLER earth loop resistance to comply with 0.4.sec disconnection...normally you will expect the larger device to require a smaller resistance to operate in 0.4.sec?
Is this right?, or am I interpreting the regulations correctly?
It seems that the lower rated device needs a SMALLER earth loop resistance to comply with 0.4.sec disconnection...normally you will expect the larger device to require a smaller resistance to operate in 0.4.sec?
Is this right?, or am I interpreting the regulations correctly?