The Advantages Of Current Monitoring Relays - Siemens SIRIUS 3RT Series System Manual

SIRIUS 3RR2 current monitoring relays
8.2 Product description
8.2.4

The advantages of current monitoring relays

● Can be mounted directly on 3RT2 contactors; in other words, there is no need for
additional wiring in the main circuit
● Ideally matched to the technical properties of 3RT2 contactors
● No need for separate current transformers
● Versions with wide-range power supply
● Can be adjusted to monitor for overshoot or undershoot, or to support range monitoring
● Freely parameterizable delay times and RESET behavior
● Display of actual value and status messages
● All versions have removable control circuit terminals
● All versions have screw terminals or, alternatively, innovative spring-loaded terminals
● Threshold values can be calculated with ease by means of direct reference to actually
measured values under setpoint load
● Range monitoring and selectable active current measurement mean that only one device
is needed to monitor a motor along the entire torque curve
● Other types of monitoring supported in addition to current monitoring include monitoring
for cable breaks, phase failure, phase sequence, residual current, and motor blocking
● An adapter can be used to implement stand-alone assembly, or enable an overload relay
to be integrated in the feeder at the same time
686
SIRIUS Innovations
System Manual, 01/2011, A8E56203870002-03