Protection & Control

The 850R provides secure and reliable protection & autoreclose functionality by offering a comprehensive range of standard and advanced protection and control elements. The controller provides directional and non-directional overcurrent protection along with the option of single-phase tripping and reclosing. Additionally, voltage and frequency protection elements may be used to disconnect Distributed Energy Resources (DER).

Multilin 850R feeder protection relay functional block diagram

The 850 provides advanced communications technologies for remote data and engineering access, making it easy and flexible to use and integrate into new and existing infrastructures. Direct support for fiber optic Ethernet provide s high-bandwidth communications, allowing for low-latency controls and high-speed file transfers of relay fault and event record information. The 850 also supports two independent IP addresses, providing high flexibility for the most challenging of communication networks.

Coil Circuit Supervision

The driving electronics board checks the coil connection continuity of the trip/close circuit, as well as the leakage current to ground. When magnitude of any phase current falls below the undercurrent trip pickup level for the time specified by the undercurrent trip delay. The alarm and trip pickup levels should be set lower than the lowest feeder loading during normal operations.

Capacitor Voltage Alarm

The Capacitor Voltage Alarm function defines the low voltage alarm for the internal/external capacitor charging power supply circuit. This rated voltage is used for charging the external capacitors that open and close the single-pole of the recloser. If the measured voltage of the capacitors is less than the configured percentage of the rated voltage, then the Cap Volt OP operand is generated. In addition, to prevent the charger from damage due to overloading or load short faults created by incorrect wiring, bad capacitors, or hardware failures, the 850R automatically turns off the capacitor charger to prevent damage.

Recloser Wear and Recloser/OHSW Health Monitoring

The 850R relay provides recloser/OHSW health information by monitoring and analyzing the operation count, arcing energy of breaking current, arcing time, opening time, and closing time when applicable. The recloser health status depends on many factors, such as permissible operation number, magnitude of breaking current, mechanical wear and contact wear.

Time of Day Timer

The Time of Day Timer function provides the user with the ability to program control actions based on real time. There are two identical Time of Day Timers.

Application

Monitoring of the total accumulated energy/accumulated demand/minimum and maximum power demand at the end of an event or a shift interval. A shift can be defined by the breaker status operand (opclosed) or operand derived from the Time of Day Timer element.

Voltage Disturbance

The Voltage disturbance function of Voltage Swell and Voltage Sag, as described in IEEE 1159-2009. When the voltage on any phase drops below this level a voltage sag condition occurs. Voltage sags are usually associated with system faults but can also be caused by switching heavy loads or starting large motors. Short duration voltage sag may cause process disruptions. Voltage swells are usually associated with system fault conditions, but they are much less common than voltage sags. An SLG fault on the system can cause a swell to occur, resulting in a temporary voltage rise on the healthy phases. Swells can also be caused by switching off a large load, load shedding, or switching on a large capacitor bank. Voltage swell may cause failure of the components depending upon the magnitude and frequency of occurrence.

Software and Configuration

The EnerVista™ suite is an industry-leading set of software programs that simplifies every aspect of using the Multilin 8 Series. EnerVista provides all the tools to monitor the status of the protected asset, maintain the device and integrate the information measured by the Multilin 8 Series, into SCADA or DCS process control systems. The ability to easily view sequence of events is an integral part of the setup software, as postmortem event analysis is critical to proper system management.

EnerVista Launchpad

EnerVista Launchpad is a powerful software package that provides users with all the setup and support tools needed for configuring and maintaining Multilin products. The setup tools within Launchpad allow for the configuration of devices in real-time, by communicating via serial, Ethernet or modem connections, or offline by creating device setting files to be sent to devices at a later time. Included in Launchpad is a document archiving and management system that ensures critical documentation is up-to-date and available when needed.

8 Series Setup Software

8 Series Setup Software is a single setup and configuration across the platform and can reduce device setup and configuration time.