LV Node

 

TRANSFORMER STATION MEASUREMENTS

The LV-PA34 device performs supply-point measurements on the secondary side of the MV/LV transformer and transmits the data via a communications modem to the data center. Supply-point measurement involves measuring three voltages and three (or optionally four) currents. In addition to generating its own measurement data, the LV-PA34 can communicate with further proprietary or third-party devices and transmit their data as well.

TRANSFORMER STATION BRANCHING MEASUREMENTS

The LV-NODE product family's supply-point central unit, the LV-PA34, can be expanded with additional Prolan-manufactured plug & play expansion modules. This solution makes it possible to monitor multiple branches originating from a single transformer without installing multiple modem-equipped units. The LV-PMxx devices measure branches current and power, while the LV-VMxx devices check for voltage presence.

END-POINT MEASUREMENTS

Within the LV-NODE product family, the LV-VA3 device is the modem-equipped option for voltage measurement at line endpoints. Its feature set is similar to the LV-VA34, but given its intended installation environment, it cannot be expanded with additional modules and does not measure current. As a result, it has a much simpler, more efficient design and installation process.

MAIN FEATURES

  • Power quality measurements according to EN 50160, EN 61000-4-30, and EN 61000-4-15
  • Voltage measurement accuracy of 0.5%, current measurement accuracy as low as below 1%
  • Three-phase voltage measurement with an internal fuse
  • Three-phase (optionally four-wire) current measurement using a Rogowski sensor
  • Changeable current sensors with IP65 connectors
  • LTE 4G communication with either an integrated or external antenna, depending on the model
  • Optional GPS location and time synchronization
  • Support for multiple IoT protocols (e.g. MQTT, Microsoft Azure)
  • Remote configuration and firmware updates
  • Up to five minutes continuous measurement and communication in case of power failure
  • Operation from a single active phase if needed
  • LED status indicators on the device front panel
  • UV-resistant, IP65-rated enclosure
  • Installation without opening the device enclosure
  • Live installation possible (no power shutdown required)

 

MEASUREMENTS

Periodically Generated Data (Statistics):

  • Average, minimum, and maximum for each measured quantity
  • Configurable cycle time in minute resolution
  • Voltage and current RMS
  • Active, reactive, and apparent power
  • Power factor
  • Voltage and current THD
  • Individual voltage and current harmonics
  • Voltage and current asymmetry
  • Mains frequency

Events, Alarms:

  • Voltage dip
  • Voltage swells
  • Rapid voltage changes
  • Overcurrent
  • Voltage interruptions
  • Medium-voltage line break
  • Door opening

Other Data:

  • Flicker Pst1 and Pst10
Operating voltage range 100…280 VAC
Power consumption 3 W (average), max. 5 W
Operating temperature -20…70 °C
Voltage measurement 3-phase
Voltage measurement accuracy ≤0.5%
Voltage measurement range 0…280 VAC
Voltage measurement overload capability 440 VAC (1 minute)
Internal fuse 6.3 × 32 mm, 2A, 500V, I1 ≥ 20 kA
Current measurement Rogowski sensor
Current measurement accuracy ≤1%
Current measurement range 30…3000 A
Trip threshold for current measurement max. 2 A
Current measurement overload capability 20 kA
Impulse withstand voltage 6 kV
Insulation strength 2.5 kVeff
Power supply holdup time 5 minutes
Module power supply From network  through voltage measurement
Sampling frequency 32 kHz
Internal clock accuracy <1 s/day
Remote communication LTE 4G, GPRS
Communication protocols MQTT, MS Azure IoT Hub, Mender.io, NTP
Local communication 2 × RS485
IP protection IP65
Mounting With screws or band clamp (max. 18 mm width)