PLR Series - Voltage Monitor

Littelfuse Voltage Monitoring Relays
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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.

Access specifications, certifications, check availability and order parts below

Catalog #Input
Voltage (V)
Output
Form
Termination TypeMounting MethodDimensionsWeight (lbs/g)Compare
PLR120A95 to 140VACSPDTOctal 8-pin plug-inPlug-in socket rated 600V3.20 x 2.39 x 1.78 in. (81.3 x 60.7 x 45.2mm)≅6.0oz (170g)
PLR240A190 to 270VACSPDTOctal 8-pin plug-inPlug-in socket rated 600V3.20 x 2.39 x 1.78 in. (81.3 x 60.7 x 45.2mm)≅6.0oz (170g)
PLR380A340 to 450VACSPDTOctal 8-pin plug-inPlug-in socket rated 600V3.20 x 2.39 x 1.78 in. (81.3 x 60.7 x 45.2mm)≅6.0oz (170g)
PLR480A380 to 500VACSPDTOctal 8-pin plug-inPlug-in socket rated 600V3.20 x 2.39 x 1.78 in. (81.3 x 60.7 x 45.2mm)≅6.0oz (170g)