1. Low Frequency Magnetic Fields...
A general concern,
increasing use of electrical appliances
lack of knowledge on possible long term effects
MV/LV substations considered significant
rather high LV currents
vicinity of the public or working areas
then, request for "limited effects"

2. Standards & regulations
Topic is not yet mature
basic restrictions and reference levels are proposed by ICNIRP
but no general agreement on acceptable limits
no implementation in the components standards
Early regulations come up
caution principle pressure
responsibility of the "owner"

3. Technical background Actual field measurements Digital simulations
easy to perform
difficult to interpret
Digital simulations
tools already available
good relevancy
need many parameters

4. Disturbing points... Field magnitude varies as 1/d3
strong influence of the distance
an operating substation is connected, too...
cables also emit magnetic field
ownership limits are unclear for public distrib.
operating load conditions are uncontrolled
"worst case" is unachievable

5. How to assess... regulation compliance ? global performances ?
depends on the expression of requirements
global performances ?
by actual measurements under operation (?)
difficult for owner of actual installation
influences of external factors
impossible to demonstrate "worst case"

6. And then, how to assess responsibilities ?
by compliance to components standards
by the manufacturers
by respect of installation rules (or standards)
by the contractor
as currently achieved for other performances
but a big work is needed to reach that...