Undersized Main Earth Conductor

Does it look cooked, are there signs of high diverted current in the bonding conductors?.Assuming it has been there for a while and looks in good shape,  connections are tight and not corroded etc, then at most it may be a  C3. 

To compare, there are plenty of DNO heads with 6mm tail (not 16!!) coming out the side, and most of them are not dripping molten plastic, so we have to assume that in most cases the guidance for using 16mm if in doubt is erring on the side of belt and braces.


After all a chunk of 16mm won't even twitch if you use it to blow a 100 A fuse, in fact it will take 100A or more all day,  -there are plety of 16mm meter tails as well.


Nothing to say the MET cannot be in the CU or any other box if there is room, or indeed that there may be more than one marshalling blcok as well, so long as it is all solidly connected and does not look corroded or loose, then that is a tick in the box.


(The NICIEC guide) for example has in the section at the back
Departures from the requirements of the current edition of BS 7671 that do not give rise to danger or need improvement
Inadequate cross-sectional area of a mainprotective bonding conductor provided that theconductor is at least 6 mm2 and that there is no evidence of thermal damage


Now NICIEC are not the last word on this, but are a good steer for the level to aim at.


Mike.

Does it look cooked, are there signs of high diverted current in the bonding conductors?.Assuming it has been there for a while and looks in good shape,  connections are tight and not corroded etc, then at most it may be a  C3. 

To compare, there are plenty of DNO heads with 6mm tail (not 16!!) coming out the side, and most of them are not dripping molten plastic, so we have to assume that in most cases the guidance for using 16mm if in doubt is erring on the side of belt and braces.


After all a chunk of 16mm won't even twitch if you use it to blow a 100 A fuse, in fact it will take 100A or more all day,  -there are plety of 16mm meter tails as well.


Nothing to say the MET cannot be in the CU or any other box if there is room, or indeed that there may be more than one marshalling blcok as well, so long as it is all solidly connected and does not look corroded or loose, then that is a tick in the box.


(The NICIEC guide) for example has in the section at the back
Departures from the requirements of the current edition of BS 7671 that do not give rise to danger or need improvement
Inadequate cross-sectional area of a mainprotective bonding conductor provided that theconductor is at least 6 mm2 and that there is no evidence of thermal damage


Now NICIEC are not the last word on this, but are a good steer for the level to aim at.


Mike.