User Manual

GMC-I Messtechnik GmbH 53
14.1 Voltage Drop Measurement (at Z
LN
) – ΔU Function
Significance and Display of ΔU (per DIN VDE 100, part 600)
Voltage drop from the intersection of the distribution network and
the consumer system to the point of connection of an electrical
power consumer (electrical outlet or device connector terminals)
should not exceed 4% of nominal line voltage.
Calculating voltage drop (without offset):
ΔU = Z
L-N
• nominal current of the fuse
Calculating voltage drop (with offset):
ΔU = (Z
L-N
- Z
OFFSET
) • nominal current of the fuse
ΔU in % = 100 • ΔU / U
L-N
See also section 9 regarding measurement procedure and connection.
Connection and Test Set-Up
Set Parameters
Note: When the nominal current I
N
is changed with existing
ΔU
OFFSET,
the offset value is automatically adjusted.
Setting Limit Values
TAB Limit value per German technical connection conditions
for connection to low-voltage mains between the distribu-
tion network and the measuring device
DIN Limit value per DIN 18015-1: ΔU < 3% between the mea-
suring device and the consuming device
VDE Limit value per DIN VDE 0100-520: ΔU < 4% between the
distribution network and the consuming device (adjustable
up to 10% in this case)
NL Limit value per NIV: ΔU < 5%
Measurement without OFFSET
Proceed as follows:
➭ Switch OFFSET from ON to OFF.
Determine OFFSET (as %)
Proceed as follows:
➭ Switch OFFSET from OFF to ON. “ΔUOFFSET = 0.00%” is dis-
played.
➭ Connect the test probe to the point of common coupling
(measuring device / meter).
➭ Start measurement of offset with IΔ
N
.
An intermittent acoustic signal sounds first,
which is then accompanied by a blinking
warning to prevent an offset value which has
already been saved from being unintentionally
deleted.
➭ Start the offset measurement by
pressing the release key again or
abort measurement by pressing the
key
▼ ON/START (here = ESC).
ΔUOFFSET x.xx % is indicated, where x.xx may take a value
between 0.00 and 99.9 %.
An error message appears in a pop-up window in the event that
Z > 10 Ω.
Start Measurement with OFFSET
1
2
Nominal current of the fuse:
Polarity selection: Lx-N
Diameter: 1.5 to 70 sq. mm
Cable types: NY..., H03... - H07...
Number of wires: 2 ... 10-strand
Tripping characteristics: B, L
2 to 160 A
Limit value
ΔU % > limit value
U
L
⏐ R
L
ΔU
Red
2