The PLM8405 is a 3-phase voltage monitor for 380VAC systems, offering protection against undervoltage, voltage unbalance, phase loss, and phase reversal. It features an isolated 10A SPDT output relay, automatically resets upon fault correction, and uses an LED to indicate normal operation (green), fault delay (flashing red), or fault state (steady red). The unit has a compact 8-pin octal package with dimensions of 81.3 mm H × 60.7 mm W × 45.2 mm D, mounts on 35 mm DIN rail or surface, and complies with IEEE C62.41-1991 Level B surge protection, NEMA MG1 14:30/14:35, and ASME A17.1 Rule 210.6. Voltage unbalance trip is factory-set at 4%, with a trip delay of 5 seconds and a response time of ≤ 200 ms.
The PLM Series is a 3-phase voltage monitor that continuously monitors each of the three phases. Monitors both delta and wye systems and no connection to neutral is required. The microcontroller circuit design protects against undervoltage, voltage unbalance, phase loss and phase reversal. Protection is assured when regenerated voltages are present. OperationThe output relay is energized and the LED glows green when all voltages are acceptable and the phase sequence is correct. Under and unbalanced voltages must be sensed for a continuous trip 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. The LED flashes red during the trip delay, then glows red when the output de-energizes. The LED flashes green/red if phase reversal is sensed.Field AdjustmentSet voltage adjustment knob at the desired operating line voltage for the equipment. This adjustment automatically sets the undervoltage trip point. Apply power. If the PLM fails to energize, (LED glows red) check wiring of all 3 phases, voltage, and phase sequence. If phase sequence is incorrect, the LED flashes green/red. To correct this, swap any two line voltage connections at the mounting socket. No further adjustment should be required.
Industrial Relays 3PHASELINEMONITOR
Voltage Asymmetry, Voltage Sensing AC, Phase Loss 380VAC
| Littelfuse, Inc. | VAST STOCK CO., LIMITED | Quarktwin Technology Ltd. | |
|---|---|---|---|
| Product Category | Electromechanical Relays | Electromechanical Relays | Protective Relays and Monitoring Relays |
| Product Number | PLM8405 | PLM8405 | PLM8405 |
| Product Name | PLM Series – Voltage Monitor | Industrial Relays | Monitor - Relay Output |
| Mounting | Socket or Plug-in Style; Plug-in socket |
