Chapter 3
Behaviour of the Isolation Unit
Page 10 of 20
Product Description ENS31
Version: A.02
Issue: 20.09.2005
3.5
Influence of isolation units on each other
When isolation units of the type ENS31 are used, they can be imple-
mented in dense proximity in the public electricity supply without it lead-
ing to operational problems. Even in the case of long network spurs and a
mains supply subject to frequent faults, unproblematic operation can be
guaranteed.
The ENS31 automatically adapts to these difficult power supply condi-
tions. To achieve this, the following processes are integrated in the
ENS31:
•
optimised impedance measurement process,
•
automatic calibration of the measured impedance change,
•
automatic adaptation of switching thresholds to frequent fluctuations
and interference levels
•
automatic synchronisation and limitation of signal strength in the case
of frequent use of the ENS
3.6
Optimised impedance measurement process
The optimised impedance measurement process improves the resolution
and interference resistance of the impedance measurement on a large
scale. Centralised ripple control signals and frequency converters hardly
influence measurements.
An island effect is recognised by a sudden increase in the mains power
impedance.
phase shift
measured by
the ENS
test signal
island formation
local power supply
average voltage supply
ENS
