100 ohm on spur for boiler

[Farmelectrics]

a friend has just phoned me asking question the gas board has just turned up to fit new combi boiler earthing is only 6mm so i told him to put 10mm in and earth clamp with in in 1m of gas intake the gas fitter haas left the property saying he wont fit boiler because the spur has given him a 100ohms reading ive suggested he needs to test ring main in house ie r1 r2 etc check for any loose connections he then tells me the ring main is rcd protected to which i have advised him to tell the gas fitter that is acceptable because you can have reading of 1667ohms am i right thanks for your advise in advance the british gas engineer has gone to another job whats your thoughts chaps

 

[telectrix]

you are correct. the gas man probably used a simple tester. it may be a TT system. in which case 6mm earthing is adequate.

 

[Farmelectrics]

thanks for the quick reply my mate is a spark as well the system is tncs hes not happy the gas fitter has done one as is wife has taken day of work and cant get in touch with him

 

[Farmelectrics]

i would still investigate it myself and put it right

 

[telectrix]

get a Zs reading from the live busbar in the CU. if that is a daft, high reading,similar to the readings at sockets, and the Ze is within limits, then it's caused by internal components od MCBs/RCDs.

 

[Farmelectrics]

will do thanks telectrix