Zs fault

[i=p/u]

its what they teach you these days and reason i said that is because we were talking about the exact subject on monday. not always an option for new circuit or breaker device to be reduced, thats all folks!!!!!!!!!!!!!!!

 

[geoffa]

had a similar problem to be solved in the 2391 practical.
Zs value was too high for ADS.
Assuming the system is TN-C-S
Number of solutions:
Check R1 +R2 equals what you would expect using the resistances/m as shown in OSG page 166. Could indicate poor connections
Check the MCB type as it could be a C type where it may be possible to have a B type depending on what the load type is. B types have a higher max Zs value compared to C's
Could reduce the length of the circuit
Could use cables for the circuit having a larger csa

 

[lady electric]

Thank you all for your input - appreciated

 

[telectrix]

and if all else fails there is always the fast track course 7 weeks learning how to lie through your teeth, become a .......... politician, lawyer, estate agent, salesman, banker, care home manager, any manager, sure there's more.......

 

[i=p/u]

7 weeks is a long in a classroom, il stick to 1 day per week