www.janitza.de
UMG 801
41
Monitoring residual currents in an electrical system
via the residual current inputs of the device
(terminals 7/8, 9/10, 11/12 and 13/14) allows an
alarm management system to be set up with
the GridVis
®
software. This allows the system
operator to be alerted before a protective device is
triggered.
The measurements in medium and high voltage
networks are made via current and voltage
transformers.
INFORMATION
Limit values and warnings for the device or system
operator can be configured easily in the GridVis
®
software.
In the GridVis
®
software, you also configure
the ratios of the residual current transformers
separately for each residual current input.
INFORMATION
The meter is not an independent protective
device against electric shock!
7.7.1 Current direction of the residual current
transformers
For residual current measurement with current
transformers in AC operation at the measuring
inputs, the device does not distinguish between
the current directions. Incorrect connection of the
residual current transformers in AC operation does
not require subsequent rewiring.
INFORMATION
AC operation:
The meter does not distinguish between the current
directions of the residual currents.
The residual currents of the grid side or load side
are
not
directionally sensitive.
AC/DC operation:
Pay attention to the polarity when using current
transformers in AC/DC operation!
See section
„7.7.4 Connection examples -
Residual current measurement“ on page 43.
WARNING
Risk of injury due to large currents and high
electrical voltage on the current transformers!
Current transformers operated while open on the
secondary side (high voltage peaks pose a hazard
when touched) can result in severe bodily injury or
death.
·
Avoid operating the current transformers
while open; short circuit the unloaded
transformers!
·
Before interrupting the current supply,
short circuit the secondary connections of
the current transformers. Switch any test
switches that automatically short circuit the
secondary lines of the current transformers
to the “Test” status (Check the test switch/
short circuiting connection beforehand)!
·
Only use current transformers with basic
insulation to IEC 61010-1:2010!
·
Caution, even current transformers rated as
safe for open operation can pose a hazard
when touched during operation while open!
·
Make sure that screw terminals for the
current transformer connection on the device
are adequately tightened!
·
Comply with the information and provisions
in the documentation of your current
transformers!
·
Ground connections present on the
secondary windings of the current
transformers must be connected to ground!
·
Observe the general safety information for
handling current transformers and devices
with residual current measurement.
ATTENTION
Faulty cross currents, incorrect measurements,
and even damage to the device and/or your
system due to lack of galvanic isolation!
A lack of galvanic isolation of active external
current transformers (or other current sensors) on
the multifunction channels from the supply voltage
of the device can lead to faulty cross currents,
incorrect measurements or even damage to your
device and/or system.
·Do not take the auxiliary voltage supply of active
external current transformers (or other current
sensors) on the multifunction channels from the
supply voltage of the device! For each active
current transformer, use galvanically isolated
power supplies (secondary side).
·Do not ground passive current transformers
on the multifunction channels! Observe the
usage information of the current transformer
manufacturer.
Содержание UMG 801
Страница 9: ...www janitza de UMG 801 9...
Страница 31: ...www janitza de UMG 801 31...
Страница 47: ...www janitza de UMG 801 47...
Страница 91: ...www janitza de UMG 801 91...
Страница 105: ...www janitza de UMG 801 105...
