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To ensure accuracy, please note that images may be representative. Refer to the product data sheet for detailed specifications.
| Manufacturer | SSAC / Littelfuse |
| Manufacturer Product Number | HLMUDRAAA |
| Description | Voltage Monitor Relay; Lo/Hi V, Unbal, Loss, Rev; 200-480 VAC; Restart 0.6-300s |
| Datasheet | Download Datasheet |
The Littelfuse SSAC HLMUDRAAA is a 3-phase voltage monitor for 200-480 V AC motors. It protects against low voltage, high voltage, voltage unbalance, phase loss, phase reversal and over / under frequency. Sensing: Microcontroller; automatically senses the voltage range and 50 / 60 Hz; delta or wye, no neutral connection.
Trip / reset points: low voltage 88-92% of the adjusted line voltage (resets about 3% higher); high voltage 109-113% of the adjusted line voltage (resets about 3% lower); voltage unbalance 2-10% adjustable (resets about 0.7% lower).
Trip delay: 1-30 s adjustable (over / under voltage, unbalance, frequency); phase loss and reversal trip within 200 ms. Restart delay: 0.6-300 s adjustable, restart on fault correction (staggered restarting of multiple motors). Reset: Automatic. Diagnostics: Bi-color LED: flashes green during the restart delay, green when the output is energized; flashes red during the trip delay, red when tripped; flashes red/green on phase reversal.
Output: 2 Form C (DPDT), isolated, 10 A resistive @ 240 VAC; 8 A resistive @ 277 VAC; 1/4 hp @ 120 VAC, 1/3 hp @ 240 VAC (NO). Mounting: Surface mount, one #10 screw (35 mm DIN rail with P1023-20 adapter), screw terminal. Dimensions: 76.7 x 50.8 x 41.7 mm (3.0 x 2.0 x 1.64 in), H x W x D.
It operates from -40 to +60 °C and can be stored from -40 to +85 °C.
| Category | |
| Manufacturer | SSAC / Littelfuse |
| Model | HLMU |
| Monitoring Function | Low voltage, high voltage, voltage unbalance, phase loss, phase reversal, over / under frequency |
| Sensing Method | Microcontroller; automatically senses the voltage range and 50 / 60 Hz; delta or wye, no neutral connection |
| Input Voltage | 200-480 VAC |
| Input Operating Range | Adjustable nominal 200-240 VAC (50 or 60 Hz), 340-420 VAC (50 Hz), 400-480 VAC (60 Hz) |
| Maximum Voltage | 550 VAC |
| Low Voltage Trip / Reset | 88-92% of the adjusted line voltage (resets about 3% higher) |
| High Voltage Trip / Reset | 109-113% of the adjusted line voltage (resets about 3% lower) |
| Voltage Unbalance Trip / Reset | 2-10% adjustable (resets about 0.7% lower) |
| Trip Delay | 1-30 s adjustable (over / under voltage, unbalance, frequency); phase loss and reversal trip within 200 ms |
| Restart Delay (s) | 0.6-300 s adjustable, restart on fault correction (staggered restarting of multiple motors) |
| Reset Method | Automatic |
| Status Indicator | Bi-color LED: flashes green during the restart delay, green when the output is energized; flashes red during the trip delay, red when tripped; flashes red/green on phase reversal |
| Contact Configuration | 2 Form C (DPDT), isolated |
| Output Rating | 10 A resistive @ 240 VAC; 8 A resistive @ 277 VAC; 1/4 hp @ 120 VAC, 1/3 hp @ 240 VAC (NO) |
| Mounting Type | Surface mount, one #10 screw (35 mm DIN rail with P1023-20 adapter) |
| Termination Style | Screw Terminal |
| Dimensions | 76.7 x 50.8 x 41.7 mm (3.0 x 2.0 x 1.64 in), H x W x D |
| Operating Temperature (Storage) | -40...+60 °C (-40...+85 °C) |
| Mechanical Life | 1,000,000 (30,000 at 10 A) |