Here are a few rather interesting PDF files from ESB Networks that fully describe how a housing development is connected:
http://www.esb.ie/esbnetworks/downl..._se rvices_guidebook_dtis_050500_azf.pdf and how an individual one off house is connected:
http://www.esb.ie/esbnetworks/downloads/standards_codes/duct_spec.pdf Gives full details of EVERYTHING including how their minipillars, substations etc are earthed.
You may need to skip in a few pages as much of it is aimed at building contractors.
Required Earthing arrangements:
"DPC4.3 Earthing Requirements
DPC4.3.1 The treatment of the neutral is different for the various supply voltages. The present treatments are described below but these could change in the future.
DPC 4.3.2 The electrical installations of all new consumers connected at low voltage shall be protected by PME, (TNC-S unless otherwise advised) in line with the requirements of the National Rules for Electrical Installations - Electro Technical Council of Ireland (ETCI) (Item 17, Annex1). This requires that the individual appliance earth conductors be wired back to central bonding position adjacent to the incoming supply termination. No local earthing of plant or appliances is permitted within the installation.
DPC4.3.3 The central bonding terminal block shall be incorporated in a sealable enclosure which facilitates the connection of a neutralising link onto the incoming ESB neutral conductor. An earthing conductor of appropriate size should be taken from the central terminal block to the consumers earth electrode.
DPC4.3.4 For voltages above LV the following applies:
Voltage Neutral Treatment 10kV Isolated neutral throughout the country except in parts of Dublin and Cork City where it is either directly earthed or earthed through a 2 ohm or 4 ohm resistor so as to limit single-phase earth fault current to 1500 amps (typical).
20kV Earthed through a 20 ohm resistor which limits earth fault current to 500 amps.
38kV Earthed through an arc suppression coil (series inductance) at source 110kV substations.
110kV Effectively Earthed. "
[This message has been edited by djk (edited 01-20-2004).]
