The PLM6405 is a 3-phase voltage monitor for 240VAC systems, designed to protect against undervoltage, voltage unbalance, phase loss, and phase reversal without requiring a neutral connection. It features an 8-pin plug-in mount with dimensions of 81.3 mm H x 60.7 mm W x 45.2 mm D, and uses an isolated 10A SPDT relay rated for 277VAC max. The voltage unbalance trip point is factory-set at 4% with a fixed 5-second delay. The output relay energizes only when phase sequence is correct and voltages are within tolerance; automatic reset occurs after fault clearance. It includes visual LED indicators for trip states and complies with ASME A17.1 Rule 210.6, NEMA MG1 14:30/14:35, and IEEE C62.41-1991 Level B standards. Surge isolation is rated at ≥2500V RMS, and power consumption is approximately 2W.
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.
VOLTAGE SENSING RELAY, 10A, 277V, SOCKET; Product Range:PLM Series; Contact Configuration:SPDT; Contact Current:10A; Relay Mounting:Socket; Contact Voltage VAC:277V; Relay Terminals:Plug In; Contact Voltage VDC:
Industrial Relays 3PHASELINEMONITOR
Voltage Asymmetry, Voltage Sensing AC, Phase Loss 240VAC
| Littelfuse, Inc. | Newark, An Avnet Company | VAST STOCK CO., LIMITED | Quarktwin Technology Ltd. | |
|---|---|---|---|---|
| Product Category | Electromechanical Relays | Electromechanical Relays | Electromechanical Relays | Protective Relays and Monitoring Relays |
| Product Number | PLM6405 | 34AC4486 | PLM6405 | PLM6405 |
| Product Name | PLM Series – Voltage Monitor | Voltage Sensing Relay, 10A, 277V, Socket; Product Range Littelfuse | Industrial Relays | Monitor - Relay Output |
| Mounting | Socket or Plug-in Style; Plug-in socket | Socket or Plug-in Style; Socket | ||
| Poles | Single Pole (SP) | |||
| Throw | Double Throw |
