ABB RET670 Applications Manual

IEC06000537 V1 EN
Figure 316: Example of a station configuration with separated process bus and
station bus
The IED can get analog values simultaneously from a classical CT or VT and from a
Merging Unit, like in this example:
The merging units (MU) are called so because they can gather analog values from one
or more measuring transformers, sample the data and send the data over process bus to
other clients (or subscribers) in the system. Some merging units are able to get data
from classical measuring transformers, others from non-conventional measuring
transducers and yet others can pick up data from both types. The electronic part of a non-
conventional measuring transducer (like a Rogowski coil or a capacitive divider) can
represent a MU by itself as long as it can send sampled data over process bus.
Section 4 1MRK504116-UUS C
Station communication
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Application manual

ABB RET670 Specifications

General

Rated Frequency	50/60 Hz
Inputs	Analog and binary inputs
Application	Protection of power systems
Communication Protocols	IEC 61850, DNP3, Modbus
Operating Temperature Range	-25°C to +55°C
Mounting	Rack mounted
Number of Binary Inputs	Up to 48
Number of Binary Outputs	32
Protection Functions	Overcurrent Protection
Outputs	Binary outputs
Enclosure	IP 54
Type	Line Differential Protection
Number of Analog Inputs	24