The PLR480A is a voltage monitoring relay for 380 to 500VAC systems, designed to prevent 3-phase motor startup under undervoltage or phase loss conditions and enforce correct A-B-C phase sequence. It mounts via an octal 8-pin plug-in socket and features an LED for visual status indication. The relay has a SPDT electromechanical output rated at 5A resistive at 240VAC and 1/4 Hp at 120VAC, with pull-in and drop-out times of ≤400ms and ≤100ms respectively. Isolation voltage is ≥2500V RMS input to output. It meets ASME A17.1 Rule 210.6, NEMA MG1 14:30, 14:35, and IEEE C62.41-1991 Level B standards. Operating temperature ranges from 0°C to 55°C, and physical dimensions are 81.3 mm H x 60.7 mm W x 45.2 mm D. Weight is approximately 170 g.
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. OperationThe 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.
Voltage Sensing AC, Phase Loss, Phase Sequence 380 ~ 500VAC
Industrial Relays 3PHASELINEMONITOR
| Littelfuse, Inc. | Quarktwin Technology Ltd. | VAST STOCK CO., LIMITED | |
|---|---|---|---|
| Product Category | Electromechanical Relays | Protective Relays and Monitoring Relays | Electromechanical Relays |
| Product Number | PLR480A | PLR480A | PLR480A |
| Product Name | PLR Series – Voltage Monitor | Monitor - Relay Output | Industrial Relays |
| Mounting | Socket or Plug-in Style; Plug-in socket rated 600V |
