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. Operation Upon application of line voltage, the output is de-energized and the restart delay begins. If all the three-phase voltages are within the acceptable range, the output energizes at the end of the restart delay. The microcontroller circuitry automatically senses the voltage range, and selects the correct operating frequency (50 or 60Hz). The over and under voltage trip points are set at ± 10% of the adjusted line voltage. When the measured value of any phase voltage exceeds the acceptable range limits (lower or upper) the trip delay begins. At the end of the trip delay the output relay de-energizes. If the phase voltage returns to an acceptable value before the trip delay expires, the trip delay is reset and the output remains energized. Under, over, and unbalanced voltages plus over or under frequency must be sensed for the complete trip delay before the unit trips. The unit trips in 200ms when phase loss or reversal are sensed. The unit will not energize if a fault is sensed as the line voltage is applied. Reset: Reset is automatic upon correction of the voltage or frequency fault or phase sequence. Specifications Line Voltage Type 3-phase delta or wye with no connection to neutral Operating Voltage 200-480VAC Voltage Range Adj.Range Frequency 240 200-240VAC 50/60Hz380 340-420VAC 50Hz480 400-480VAC 60Hz Line Voltage Max. 550VAC AC Line Frequency 50/60 Hz automatically detected Phase Loss ≥ 25% unbalance Response Time ≤200ms Undervoltage & Voltage Unbalance Type Voltage detection with delayed trip & automatic reset Overvoltage TripVoltage 109 - 113% of the adjusted line voltage Reset Voltage ≅ -3% of the trip voltage Undervoltage Trip Voltage 88 - 92% of the adjusted line voltage Reset Voltage ≅ +3% of the trip voltage Voltage Unbalance Trip Setpoint Adjustable 2 - 10% or specify fixed unbalance of 2 - 10% in 1% increments Reset on balance ≅ -0.7% unbalance Trip Delay Active On Over/undervoltage, voltage unbalance, over/under frequency Range Adjustable from 1 - 30s or specify fixed delay 1 - 30s in 1s increments Tolerance ± 15% Restart Delay Range Adjustable from 0.6 - 300s; if no restart delay is selected a 0.6s initialization delay applies Tolerance ± 15% Over/Under Frequency ±4%; Reset ±3%; 50/60 Hz Phase Sequence A, B, C, L1, L2, L3 Response Time -Phase Reversal & Phase Loss ≤200 ms Reset Automatic Output Type Isolated Electromechanical Relay Form DPDT Rating 10A resistive @ 240VAC;8A resistive @ 277VAC; NO-1/4 hp @ 120VAC;1/3 hp @ 240VAC Life Mechanical - 1 x 10⁶Electrical (at 10A) - DPDT - 1 x 30³ Protection Phase Reversal/Failure ASME A17.1 Rule 210.6 Motors and Generators NEMA MG1 14:30, 14:35 Surge IEEE C62.41-1991 Level B Isolation Voltage ≥ 2500V RMS input to output Circuitry Encapsulated Mechanical Mounting Surface mount with one #10 (M5 x 0.7) screwNote: 0.25 in.(6.35 mm) spacing betweenunits or other devices is required Dimensions H 76.7 mm (3.0”) W 50.8 mm (2.0”)D 41.7 mm (1.64”) Termination Screw terminal connection up to 12 AWG (3.3 mm² ) wire Environmental Operating/Storage Temperature -40° to 60°C / -40° to 85°C Humidity 95% relative, non-condensing Weight ≅ 3.9 oz (111 g)
