More on SAGE generally and the Second Interim Assessment in particular, or download the Assessment here.
The recommendations in the SAGE Second Interim Assessment are from one of the following:
"Should"
- existing best practice which should continue with a recognition that EMFs are an extra reason for doing them
- new measures that should be introduced
"Could"
- further investigation needed before a recommendation is made
- "consumer choice": not recommended generally but available if an interested party does not mind bearing the cost
"Don't"
- because the option is not effective
- because the cost would be disproportionate
- because there would be adverse safety consequences
SAGE groups the options by the different parts of the distribution system and we list the recommendations here:
Options relating to net currents in distribution circuits
more on what net currents are and how they arise
Should (reinforce and endorse existing practice):
- DNOs make reasonably practicable efforts to balance loads on three-phase final distribution circuits
- DNOs assist customers with three-phase supplies to balance loads to the extent reasonably practicable
- DNOs investigate and repair broken neutrals
- Disconnect redundant cables
- Use plastic gas and water pipes for new build
- Insert plastic sections in metal gas and water pipes when work is being done anyway
Could (consumer choice)
- Consumer chooses to use TT system (local earth)
- Retrofit plastic sections in existing gas and water pipes where work is not otherwise being done
Could (further investigation needed)
- Replace some or all neutral links with inductive links
- Routine measurememts to identify broken neutrals
- Inductors on service cables
Don't
- Improve balance of loads where this involves remaking joints
- Legally require balanced loads
- Abandon protective multiple earthing for new build
- Abandon protective multiple earthing for existing networks
- Alter pme regulations to require fewer earths
- Remove some or all neutral links in link boxes
- Remove bonds from lightning conductors to electrical earths
- Change regulations to stop steelwork bonds
- Larger neutral conductors
Options relating to wiring in multi-occupancy buildings
Should (reinforce and endorse existing practice)
- Site plant rooms away from occupied areas (new build)
- Risers to use SNE cables (new build)
- Risers to use compact design
Could (available as consumer choice)
- Site plant rooms away from occupied areas (retrofit)
- Risers to use SNE cables (retrofit)
- Risers to use compact design (retrofit)
- Screen the fields
Options relating to intermediate voltage circuits
Should (new measure)
- Heavily loaded double-circuit intermediate-voltage lines to have optimal phasing and balanced loads to the extent reasonably practicable
Could (further investigation needed)
- Restrictions on routing new heavily loaded intermediate-voltage lines close to homes, schools and other public places
Options relating to final distribution substations
more on substations and the fields they produce
Should (endorse and reinforce existing practice)
- Comply with relevant exposure limits
- Reasonably practicable efforts to site substations distant from homes etc
- New substations to have compact design where reasonably practicable
- Use compact designs for refurbishment where reasonably practicable
Should (new measure)
- Arrange components in the substation in the lowest-exposure layout reasonably practicable if compact design not possible
- DNOs to consider instances of substations producing elevated exposures when requested and offer options for reducing the exposures at the consumer's choice and cost
- DNOs to record instances of substations producing particularly high exposures so that EMF issues can be factored in to future investment and maintenance decisions for that substation
Could (consumer's choice)
- Relocate the substation
- Retrofit whole substation with compact design
- Retrofit LV Board with compact design
- Bundle the cables between substation and LV Board to produce more compact design
- Screen the fields
Could (further investigation needed)
- Possible limits on fields produced in homes etc by new substations
Don't
- Substation perimeter fence to include larger area
- Univeral retrofit of field reduction measures
Options relating to Training and Response
Should (new measure)
- Information for the public
- DNOs to investigate EMF issues when notified of them
- Develop awareness within DNOs, by training of relevant staff, of how elevated exposures can be an indication of system problems
