3-Phase Monitor with Adjustable Trip & Restart Delays

20AA-HM

The 20AA-HM 3-Phase Monitor provides essential protection for industrial equipment by continuously monitoring critical electrical parameters. This unit detects phase loss, phase reversal, over/under voltage, and voltage unbalance, safeguarding machinery from damaging conditions. Its adjustable trip delay, configurable from 1 to 30 seconds, allows operators to fine-tune response times to transient events, preventing unnecessary shutdowns while ensuring prompt action when required. An adjustable restart delay, ranging from 1 to 500 seconds, facilitates controlled system recovery, minimizing stress on components. Operating efficiently within a 475-600 VAC range, the 20AA-HM integrates into diverse high-voltage applications. The manual reset feature ensures deliberate system re-engagement following a fault, enhancing operational safety and control. This monitor contributes to sustained equipment uptime and reduced maintenance requirements through precise, reliable monitoring.

Unv 3Ph Monitor

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20aa-hm

Specifications

Model TypeManual Reset
Manual Reset RequirementExternal N.O. momentary pushbutton required for manual reset.
Monitored ConditionsPhase Loss, Phase Reversal, Over/Under Voltage and Voltage Unbalance
IndicatorsLED Status Indicators
Operating Voltage475-600 VAC
Power Consumption4.5W at 600V
Auto RangesNo
Frequency50/60Hz
Type of MeasurementRMS
Under Voltage Trip90% ±1% (% of setpoint)
Under Voltage Reset93% ±1% (% of setpoint)
Over Voltage Trip110% ±1% (% of setpoint)
Over Voltage Reset107% ±1% (% of setpoint)
Voltage Unbalance Trip2-8%, adjustable
Voltage Unbalance ConformanceNEMA
Voltage Unbalance ResetTrip setting minus 0.7%
Trip Delay Time (Over, Under, & Unbalanced)1-30 sec., adjustable
Trip Delay Time (Single-Phasing Faults)1 sec., fixed
Trip Delay Time (Unbalance > 15%)1 sec., fixed
Restart Delay1-500 sec., adjustable
Manual Reset Input5V open circuit/500µA short circuit
Output Contacts2x N.O. (Isolated)
Output Contact Rating7.5A at 240VAC resistive
Operating Temperature-20° to +140° F
Humidity Tolerance0-97% w/o condensation
Terminal Torque3.5 in. lbs. maximum
Wire TypeStranded or solid 14-26 AWG, 1/terminal
Enclosure MaterialNoryl plastic
MountingDIN Rail or Surface Mount
Dimension Tolerance±0.06
Optional Feature/SG = Silver with Gold Flash Contacts
Warranty5-year Unconditional Warranty

FAQs

How does the 20AA-HM monitor voltage conditions?
The 20AA-HM monitors for over/under voltage, with trip settings at 110% and 90% of the setpoint, respectively. It also detects voltage unbalance, adjustable from 2-8%.
What are the adjustable timing parameters for the 20AA-HM?
This monitor features an adjustable trip delay time of 1-30 seconds for over, under, and unbalanced voltage conditions, and an adjustable restart delay of 1-500 seconds.
Is a manual reset required for the 20AA-HM after a fault?
Yes, the 20AA-HM is a manual reset model type. An external N.O. momentary pushbutton is required for system re-engagement.