The 350 is a member of the new SR 3 series family of protection and control devices from Multilin. This cost-
effective protective device is used to perform primary circuit protection on low and medium voltage feeders.
The protection functions of this relay include multiple phase, ground, and neutral time and instantaneous
overcurrent elements, plus essential feeder breaker control features such as cold load pickup blocking,
breaker failure, and auto-reclose. The 350 also offers enhanced features such as diagnostics, preventative
maintenance, arc-flash mitigation and security.
Easy to use and cost-effective overcurrent protection and control
Effortless draw-out construction
Environmental monitoring system to alarm on destructive operating conditions
Setup in one simple step
Accelerated Life Cycle Tested ensuring reliability
Advanced power system diagnostics
Flexible communications with multiple ports & protocols allowing seamless integration
Arc flash mitigation via zone inter-tripping, flex curves, and multiple settings group Infrastructure Protection
Powerful Security Audit Trail tool to increase security and minimize system risks
Industrial feeders with enhanced breaker monitoring diagnostics.
Medium voltage Utility feeders with advanced control features , i.e.: Cold Load Pickup, auto-reclose, multiple settings group.
Phase, neutral and ground TOC and IOC ANSI, IAC,
IEC flex curves
Cable Thermal Image Protection
Breaker Failure
Cold Load Pick Up
Four-shot auto-reclose
8 digital inputs, 7 contact outputs
Two setting groups
The 350 relay is a member of the SR 3 Series family of Multilin relays. This protective device is used to perform primary circuit protection on medium voltage feeders. The basic protection function of this relay includes multiple phase, ground, and neutral time and instantaneous overcurrent elements for coordination with upstream and downstream devices. Additionally, the device provides essential feeder breaker control features such as cold load pick up blocking, breaker failure, and auto-reclose.
The robust 350 streamlines user work flow processes and simplifies engineering tasks such as configuration, wiring, testing, commissioning, and maintenance. This cost-effective relay also offers enhanced features such as diagnostics, preventative maintenance, arc flash mitigation and security.
Event Recorder: 256 events
Oscillography with 32 samples per cycle
IRIG-B clock synchronization
Relay health diagnostics
Security audit trail
Analyze power system disturbances with transient fault recorder and event records
Preventative Maintenance:
The 350 allows a user to track relay exposure to extreme environmental conditions by monitoring and alarming at high ambient temperatures
Arc Flash Mitigation:
The 350 relay is equipped with multiple setting groups and two user definable inverse curves — FlexCurves A and B for fast and reliable arc-flash detection and breaker operation
Temperature Monitoring:
The 350 continually monitors ambient temperature around the relay and alarms when device is exposed to extreme temperatures
Advanced Device Health Diagnostic:
These diagnostic tests monitor for conditions that could impact and present device status via SCADA communications and front panel display
Eight logic elements available for simple logic for applications such as manual control, interlocking, and peer to peer tripping.
Easy integration into new or existing infrastructure. With several ethernet and serial port options, and a variety of protocols, the 350 provides advanced and flexible communication selections for new and existing energy management, SCADA, and DCS systems.
The 350 incorporates the latest communication technologies making it the easiest and the most flexible feeder protection relay for use and integration into new and existing infrastructures. The 350 relay provides the user with one front USB and one rear RS485 communication port. It also offers the option of an additional rear communication port with Ethernet Fiber and Copper. Through the use of these ports, continuous monitoring and control from a remote computer, SCADA system or PLC is possible. With our advanced draw-out construction, the 350 relay can be drawn-out without having to disconnect any communication cables.
The 350 supports popular industry standard protocols enabling easy, direct integration into electrical SCADA and HMI systems. The protocols supported by the 350 include:
EC 61850 GOOSE
DNP 3.0
Modbus RTU
Modbus TCP/IP
IEC 60870-5-103
IEC 60870-5-104
These protocols make it easy to connect to a Utility or Industrial automation system,
eliminating the need for external protocol converter devices.
The EnerVista™ suite is an industry leading set of software programs that simplifies every aspect of using the 350 relay. The EnerVista suite provides all the tools to monitor the status of the protected asset, maintain the relay, and integrate the information measured into DCS or SCADA monitoring systems. Convenient COMTRADE and sequence of event viewers are an integral part of the 350 setup software and are included to ensure proper protection and system operation. Learn More
Access Control
Multilin devices and relays are designed with simple but powerful security to enable reliability and compliance for virtually any project or implementation. With support for multi-level permissions and multi-factor supervisory controls, Multilin devices can help you manage the integrity of your system during commissioning, testing, implementation, and beyond.
The 3 Series family provides separate authentication for settings and commands to the system. In addition, as discrete authentications for local and remote access, it also provides a supervisory control factor that can lock or unlock a device for configuration changes and other modifications.
Intrusion Detection
Multilin’s family of protection and control products can also help enable your security perimeter and intrusion detection programs. By providing essential alarming and logging of critical events, Multilin devices can help you detect potential breaches within your system and allow you to respond quickly and effectively. Specifically, unsuccessful access attempts are logged, alarmed, and lead to potential attackers being locked out. This ensures the reliability of your system during questionable activity
control factor that can lock or unlock a device for configuration changes and other modifications.
Auditing and Reporting
With the Security Audit Trail reporting feature and support for Event logging of key activities such
as configuration changes, Multilin devices can help ensure device and protection system integrity,
and perform forensic auditing of activities and changes for compliance.
Protection & Control 
