PLR480A - PLR Series

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Littelfuse Voltage Monitoring Relays
The PLR Series provides a cost effective means of preventing 3-phase motor startup during adverse voltage conditions. Proper A-B-C sequence must occur in order for the PLR’s output contacts to energize. In addition, the relay will not energize when an undervoltage or phase loss condition is present. The PLR protects a motor against undervoltage operation. The adjustment knob sets the undervoltage trip point.


Operation
The output relay is energized and the LED glows when all voltages are acceptable and the phase sequence is correct. Undervoltage must be sensed for a continuous dropout delay period before the relay de-energizes. Reset is automatic upon correction of the fault condition. The output relay will not energize if a fault condition is sensed as power is applied.

Property (Mouseover for details) Value
Input Voltage (V) 380 to 500VAC
Input Voltage Maximum (V) 530VAC
Input Type 3-phase delta or wye with no connection to neutral
Input AC Line Frequency (Hz) 50/60Hz
Input Phase Sequence ABC
Maximum Output Voltage (V) 250VAC
Output Type Electromechanical relay energized when all voltages are acceptable
Output Form SPDT
Output Load Rating (VA) 5A resistive @ 240VAC; 1/4hp @ 120VAC
Undervoltage Trip Voltage 350-480VAC adjustable
Drop_out Response Time (ms) ≤100ms Hysterisis: ≅2%
Pull-in Response Time (ms) ≤400ms Hysterisis≅2%
Isolation Voltage (V) ≥2500V RMS input to output
Surge Protection IEEE C62.41-1991 Level B
Termination Type Octal 8-pin plug-in
Mounting Method Plug-in socket rated 600V
Operating Temperature 0° to 55°C (32°F to 131°F)
Storage Temperature (F/C) -40° to 85°C (-40°F to 185°F)
Dimensions 3.20 x 2.39 x 1.78 in. (81.3 x 60.7 x 45.2mm)
Weight (lbs/g) ≅6.0oz (170g)