hello,
long story so ill try and keep it short...
our mains supply goes into a stand alone 80amp 30ma RCD then into a industrial fuse box with a TT earth.
this box then feeds us with MCBS to sockets lights etc. there are also several supplys going out via SWA cable to a few out buildings.
the one in question a 50amp mcb that feeds another std CU via SWA to another building...pic below.
first question, is that a RCD in above pic? if so, why if there is a problem at that end with a supply from the crabtree CU, does it trip out the main RCD... IE us... everything goes dark...!!
is it because its a 100ma RCD and the first main one being 30ma trips first?
if this is the case, can the 100ma RCD in the crabtree be changed for a 30ma one stoping our nuisance tripping?
ie this... http://cgi.ebay.co.uk/STARBREAKER-R...UK_BOI_CircuitBreakers_RL?hash=item45f02f6654
i guess the above would need a main ISO too?
thanks in advance.
long story so ill try and keep it short...
our mains supply goes into a stand alone 80amp 30ma RCD then into a industrial fuse box with a TT earth.
this box then feeds us with MCBS to sockets lights etc. there are also several supplys going out via SWA cable to a few out buildings.
the one in question a 50amp mcb that feeds another std CU via SWA to another building...pic below.
first question, is that a RCD in above pic? if so, why if there is a problem at that end with a supply from the crabtree CU, does it trip out the main RCD... IE us... everything goes dark...!!
is it because its a 100ma RCD and the first main one being 30ma trips first?
if this is the case, can the 100ma RCD in the crabtree be changed for a 30ma one stoping our nuisance tripping?
ie this... http://cgi.ebay.co.uk/STARBREAKER-R...UK_BOI_CircuitBreakers_RL?hash=item45f02f6654
i guess the above would need a main ISO too?
thanks in advance.
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