SIEMENS
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Siemens IC 10 · 2017
Relays
SIRIUS 3UG45, 3UG46 Monitoring Relays for Stand-Alone Installation
Insulation Monitoring
General data
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Overview
SIRIUS 3UG458. insulation monitor
Insulation monitoring relays are used for monitoring the insula-
tion resistance between ungrounded single or three-phase AC
supplies and a protective conductor.
Ungrounded, i. e. isolated networks (IT networks) are always
used where high demands are placed on the reliability of the
power supply, e.g. emergency lighting systems. IT systems are
supplied via an isolating transformer or by power supply sources
such as batteries or a generator. While an initial insulation fault
between a phase conductor and the ground effectively grounds
the conductor, as a result no circuit has been closed, so it is pos-
sible to continue work in safety (single-fault safety). However, the
fault must be rectified as quickly as possible before a second in-
sulation fault occurs (e.g. according to DIN VDE 0100-410). For
this purpose insulation monitoring relays are used, which con-
stantly measure the resistance to ground of the phase conductor
and the neutral conductor, reporting a fault immediately if insu-
lation resistance falls below the set value so that either a con-
trolled shutdown can be performed or the fault can be rectified
without interrupting the power supply.
Two device series
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3UG4581 insulation monitoring relays for ungrounded
AC networks
•
3UG4582 and 3UG4583 insulation monitoring relays
for ungrounded DC and AC networks
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Benefits
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Devices for AC and DC systems
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All devices have a wide control supply voltage range
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Direct connection to networks with mains voltages of up to
690 V AC and 1 000 V DC by means of a voltage reducer
module
•
For AC supply systems: Frequency range 15 to 400 Hz
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Monitoring of broken conductors
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Monitoring of setting errors
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Safety in use thanks to integrated system test after startup
•
Option of resetting and testing (by means of button on front or
using control contact)
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New predictive measurement principle allows very fast
response times
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Application
IT networks are used, for example:
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In emergency power supplies
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In safety lighting systems
•
In industrial production facilities with high availability
requirements (chemical industry, automobile manufacturing,
printing plants)
•
In shipping and railways
•
For mobile generators (aircraft)
•
For renewable energies, such as wind energy and
photovoltaic power plants
•
In the mining industry
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