The HLMUDRAAA is a 3-phase voltage monitoring relay in the HLMU Series, featuring isolated 10A DPDT relay contacts and adjustable restart delay. It monitors over, under, and unbalanced voltage, phase reversal, and frequency deviations, tripping within 200ms for phase loss or reversal. Nominal line voltage, voltage unbalance, and trip delay are knob-adjustable, with restart delay range of 0.6 to 300 seconds. The unit operates on 200-480VAC, supports both delta and wye systems without neutral connection, and has encapsulated, finger-safe terminals meeting IEC 61000 safety requirements. It mounts via surface mounting with one #10 screw or DIN rail (35mm), measures 76.7 mm H × 50.8 mm W × 41.7 mm D, and weighs approximately 111 g. The LED indicates status, and reset is automatic upon fault correction.
The HLMU Series is a universal voltage, encapsulated, 3-phase voltage monitor. It continuously measures the voltage of each of the three phases with microcontroller accuracy and compares the value to preset trip points. It separately senses phase reversal and loss; over, under and unbalanced voltages; and over or under frequency. Protection is assured during periods of large average voltage fluctuations, or when regenerated voltages are present. The unit trips within 200ms when phase loss is detected. Adjustable time delays are included to prevent nuisance tripping and short cycling of sensitive equipment. The isolated, 10A, DPDT relay contacts trip when a phase voltage exceeds the trip limits for the trip delay. Nominal line voltage, voltage unbalance, and time delays are knob adjustable. The phase loss setpoint and the acceptable frequency range are fixed. Both delta and wye systems can be monitored; no connection to neutral is required. See datasheet for operation details.
Voltage Asymmetry, Voltage Sensing AC, Phase Loss 200 ~ 480VAC
| Littelfuse, Inc. | Quarktwin Technology Ltd. | |
|---|---|---|
| Product Category | Electromechanical Relays | Protective Relays and Monitoring Relays |
| Product Number | HLMUDRAAA | HLMUDRAAA |
| Product Name | HLM Series – Voltage Monitor | Monitor - Relay Output |
| Mounting | Surface mount with one #10 (M5 x 0.7) screw |
