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Protection Relays

Protection Relays
Protection relays are electronic components designed to prevent unnecessary trips, isolate faults and protect motors, breakers, and other equipment.
Modern protective relays are microprocessor-based, and use inputs and settings to intelligently compare measurements to setpoints and produce a desired output. Inputs can include variables like current, voltage, resistance and temperature. If any of those values exceed a prescribed setpoint, the relay can trigger an output like an alarm, an indicating light, a network communication, and even turn another device on or off.
Because modern protection relays use digital technology to operate, they can produce quick, reliable, repeatable outputs far more frequently over a longer lifetime. They also provide better accuracy to eliminate nuisance trips, reduced maintenance needs to improve uptime, and better efficiency to cut costs and save panel space.
Modern protective relays are microprocessor-based, and use inputs and settings to intelligently compare measurements to setpoints and produce a desired output. Inputs can include variables like current, voltage, resistance and temperature. If any of those values exceed a prescribed setpoint, the relay can trigger an output like an alarm, an indicating light, a network communication, and even turn another device on or off.
Because modern protection relays use digital technology to operate, they can produce quick, reliable, repeatable outputs far more frequently over a longer lifetime. They also provide better accuracy to eliminate nuisance trips, reduced maintenance needs to improve uptime, and better efficiency to cut costs and save panel space.

- Protects From Loss of Any Phase
- Protects From Phase Reversal
- Protects From Rapid Cycling
- Compact Design
- Standard Surface or DIN Rail Mountable

- Protects From Low Voltage
- Protects From Reverse Phase
- Diagnostic LED
- Optional High Voltage Protection
- 8-Pin Plug-In

- Monitors Delta or Wye Systems
- Monitors up to 480 VAC
- Fixed, Lock Shaft, or Screwdriver Adjustment
- Automatic Reset with Manual Option Available
- Plug-in or Surface Mount Styles
When a phase is lost while the motor is running, a condition known as regeneration occurs where a voltage is induced into the open phase nearly equal in magnitude to the normal phase-to-phase voltage. However, with the exception of lightly loaded motors, enough change is detected by the SLA to provide the required protection when properly adjusted.
Protects against:
- Phase Loss
- Under Voltage
- Phase Reversal

- Network Programmable
- Programmable with 9-volt battery prior to installation
- Automatic reset with 3 seperate restart delay timers
- RS-485 communications port
- 3-digit LED diagnostic display
The 777-P2 incorporates a 3-digit LED display that is used for programming, providing real-time operational information and displaying diagnostic codes to aid in troubleshooting a fault condition.
Protects 3-phase motors from:
- High Voltage
- Low Voltage
- Reverse-phase
- Current unbalance
- Ground fault, Class II

- Selectable over or under current sensing
- Toroidal through hole wiring
- 0.5 - 50A trip points
- Adjustable or factory fixed trip delays
- Isolated, 10A, SPDT output contacts
- 5% trip point hysteresis (dead band)

- Reliable
- Ideal for directdrive units
- Low setpoint
- Installation flexibility
- Electrical load status
- Direct-drive units,exhaust fans,process motors,and other fixed loads
- Lighting run times and status
- VFD output On/Off status
- Direct-Drive units,unit vents,fan coil units,exhaust fans,and other fixed loads

- Protects against phase & reversal; & over, under & unbalanced voltages
- Octal plug-in
- Isolated, 10A, SPDT output contacts
- Operates from 200 to 480VAC
- LED indicator glows green when voltages are acceptable, red for faults
- Indicates reverse-phase wiring
- Simple 3-wire connection for delta or wye systems

- Monitors Both Delta and Wye Systems
- Monitors up to 550 VAC
- Automatic or Manual Reset
- Adjustable Fault and Restart Delays
- Din Rail or Surface Mount Options

- Protects From Loss of Any Phase
- Protects From Low Voltage
- Surface Mount with Optional DIN Rail Mount
- Finger Safe Barrier Strip Cover
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