The Unipower HPL110A is a compact digital motor load monitor for 3x380-440 Vac motors, using true kW measurement to act as a shaft power monitor for pumps, conveyors and other driven machines. It combines min and max load limits, peak detection, programmable hysteresis and a 4-20 mA analogue output in a 72 x 72 mm panel mount unit. Other mains voltage versions are available on special request, making the HPL110A a flexible choice for accurate motor load protection and process monitoring.
🔧 Technical Highlights
- Supply and measuring voltage: Standard model for three phase 3x380-440 Vac motors; other fixed supply variants are available to special order.
- Current range: Built in current transformer for direct measurement up to 8 A full scale, with external n:5 CTs used for higher currents.
- Measured value: True motor load in kW, displayed as percent of the selected measurement range on a digital display.
- Load limits: One Max and one Min limit detector share a SPDT relay (Limit 1 = Off or Max, Limit 2 = Off or Min) for over and underload protection.
- Hysteresis and reset: Programmable hysteresis band between trip and reset levels ensures stable operation without relay chatter.
- Start timer: Adjustable start delay masks the high inrush and transient load during motor start.
- Response time: Fast electronic measurement with typical reaction times of a few tens of milliseconds.
- Analogue output: 4-20 mA analogue output proportional to motor load (percent kW) for PLC or SCADA.
- Programming: All parameters set from the front panel using three push buttons and the digital display.
- Mounting: 72 x 72 mm panel mount (approx. 70 x 70 mm cut out) with a clear front panel indication of motor load and status.
✅ Benefits
- True kW based protection follows real shaft load and torque, not just current.
- Overload and underload protection in one unit using Min and Max limits.
- Digital percent kW display and peak detection simplify commissioning.
- Sensorless machine protection using the motor as the load sensor.
- 4-20 mA output provides a clean motor load signal for PLC and SCADA.
🚀 Typical Applications
- Pumps: dry run protection, blocked strainers, closed valves and cavitation detection.
- Conveyors: jam and overload protection for screw, belt and bucket conveyors.
- Fans and blowers: detection of broken belts, closed dampers and abnormal airflow.
- Separators and screens: supervision of load on screens, macerators and scrapers.
- Mechanical drives: indication of mechanical stress on gearboxes and couplings.
HPL110A is a proven digital motor load monitor that gives fast, accurate kW based protection and a clear picture of how your machine is really loaded. It is a simple way to upgrade from basic current protection to true shaft power monitoring on standard three phase motors.
FAQs
- Q: What motor sizes can I use HPL110A with?
A: HPL110A measures up to 8 A directly. For higher currents you can use a standard n:5 current transformer to match the motor current to the internal range.
- Q: Is HPL110A suitable for pump dry run protection?
A: Yes. By setting suitable Min and Max limits, HPL110A can detect both low load (dry running or loss of medium) and high load (blockages or closed valves) on pumps.
- Q: Can I use the 4-20 mA output with my PLC?
A: The 4-20 mA output is designed for direct connection to PLC analogue inputs, giving a signal proportional to motor load in percent kW.