Section 1: Introduction; Current Transformer Circuits; External Resistors; Description - Siemens 7SR105 Rho User Manual

Section 1: Introduction

This manual is applicable to the following relay:
• 7SR105 Rho Motor Protection relay
General Safety Precautions
1.1

Current Transformer Circuits

The secondary circuit of a live CT must not be open circuited. Non-observance of this precaution can
!
result in injury to personnel or damage to equipment.
1.2

External Resistors

Where external resistors are connected to the relay circuitry, these may present a danger of electric
!
shock or burns, if touched.
1.3

Description

The 7SR105 Rho Motor Protection Relay is developed by using the latest generation of hardware technology.
7SR105 is a member of Siemens Reyrolle
The 7SR105 Rho Motor Protection Relay is housed in a 4U high, size 4 non draw-out case and these relays
provide protection, monitoring, instrumentation, and metering with integrated input and output logic, data logging
and fault reports.
Communication access to the relay functionality is via a front USB port for local PC connection or rear electrical
RS485 (optional) port for remote connection.
©2018 Siemens Protection Devices
®
protection devices Rho product family.
7SR105 Rho Description of Operation
Chapter 1 Page 6 of 57