New Member

[PAdams]

Hi from a new member, recently qualified as Part P Domestic Electrition after 40 years in Aerospace Industry repairing Avionic Systems and Automatic Test Stations. Also been involved with electrical equipment installation.

Who should I contact for the System Design information for the connection to a dwelling, i.e. Prospective Fault Current (Ipf), Maximum earth fault loop impedance (Ze) of the earth fault path outside the consumer's installation etc,

I need to replace a consumer unit and contacted the supplier to get an isolator fitted between the meter and the CU, which they have now done but they could not give me this information. The Electrition who fitted the isolator suggested contacting the National Grid. I did ask this question during my training but got a very ambiguous response. There must be a direct contact route to get this sort of information.

 

[Marvo]

I'm sure the DNO can give you basic info about the supply or the PFC and Ze can be obtained accurately yourself by measurement.

 

[davesparks]

Did your mentor not tell you about this when you were an apprentice?
The answer is that nobody actually knows the answer for most domestic properties, and what's more they rarely care! They will give you a stated maximum PFC/PSCC and Guideline maximum Ze but nothing more than that.

 

[Richard Burns]

Usually somewhere on the DNOs' websites is a technical information section that will specify somewhere in the middle of it the 0.35Ω for TNCS and 0.8Ω for TNS systems as being the maximum Ze for domestic supply. Generally a 16kA maximum PFC may also be specified.

This is about as detailed information as you would be able to receive.

Obtaining these values by enquiry is not generally feasible and measurement is the only realistic response.

 

[Badged01]

..... after 40 years in Aerospace Industry repairing Avionic Systems and Automatic Test Stations. Also been involved with electrical equipment installation.

First welcome and second : why would a man with your skill sets want to lower himself to becoming an "electrician"??

Hopefully not because you think the work will be more challenging or the money greater?!?!?