COMBITEST422
EN - 109
➢
Verify the capability of an existing mains line to supply a load
➢
Dimension a new installation
➢
Search for possible causes of troubles on devices, loads, etc. connected to mains
Purpose of the test
Measure the maximum percentage value of voltage drop between two points of mains.
Parts of the system to be checked
The test includes two sequential impedance measurements in the initial point of mains
power line (typically downstream of a protection device) and in the final point of the same
line.
Allowable values
The instrument compares the calculated value of
V% maximum voltage drop to the set
limit value (according to applicable guidelines) according to the following relationship:
(
)
100
*
*
%
I
NOM
1
2
NOM
MAX
V
V
Z
Z
−
=
where:
Z
2
= End point impedance of the mains being tested
Z
1
= Initial point impedance (Offset) of the mains being tested (Z
2
> Z
1
)
I
NOM
= Nominal current of protection device of the mains being tested
V
NOM
= Phase-Neutral or Phase-PE nominal voltage of the mains being tested
