DIN rail power transducer

UPM304 Rail Power Transducer


  • Depth 60 mm only
  • True RMS measurement
  • More than 60 electrical parameters displayed
  • Neutral current monitoring
  • Bi-directional, four quadrants values on serial communication port
  • High contrast bright LED display
  • Power and current demand calculation during user-definable time period
  • No PTs required up to 600 (750) VAC
  • Programmable CT and PT ratios
  • User friendly


  • Switchboards, gensets, motor control centers, etc.
  • Power monitoring & control systems
  • Individual machine load monitoring
  • Demand management
  • Remote metering and cost allocation.

Available Configurations

  • Three-phase 3-wire or 4-wire unbalanced load operation.
  • True RMS metering provides accurate measurement even for distorted waveform.
  • Fully bi-directional four-quadrant values both on serial communication port and display.
  • More than 60 electrical parameters measured (instantaneous, demand, peak values, energies, etc.).
  • On request THD calculation on voltage and current.
  • Direct measurement up to 600 (750) VAC.
  • Programmable 1A / 5A current full scale.
  • Programmable CT & PT ratios.

Front panel display
  • High contrast bright, easy to read, LED display.
  • Up to three parameters displayed on the same page, with four digits plus sign digit.Up to three parameters displayed on the same page, with four digits plus sign digit.
  • Password protected setup and resetting operations.
  • RS232 or RS485 optoisolated communication port.
  • MODBUS or A2 ASCII protocol..
  • Communication speed programmable up to 57600 bps

Digital Outputs
  • Two digital outputs for energy pulsing or for alarm tripping.

Power supply

Rated voltage: 115 VAC or 230 VAC +15% -20% on request 65à·250 VAC / 90à·250 VDC on request 19à·60 VDC on request
Consumption: 2 VA max

Voltage inputs

Maximum measurable voltage: 600 (750) VAC max L-L
Input impedance: ›1.3 MOhm
Burden: max 0.15 VA per phase
Frequency: 45 - 65 Hz

Current inputs

Rated current (Ib): 1 / 5 ARMS programmable
Min / max measurable current: 20 mA / 7 ARMS
Maximum overload: 10 ARMS continuous - 100 ARMS for 1 sec.
Input impedance: 0,02 Ohm approximately
Burden: max 0,5 VA per phase
Insulation voltage: 150 VAC max between phases
Rogowski input: 200à·49995 A on request

Typical accuracy

Voltage: ±0.2% reading ±0.1% full scale
Current: ±0.2% reading ±0.1% full scale
Active power: ±1% reading ±0.2% full scale (PF=1)
Power factor: ±1% reading (0.5 inductive - 0.8 capacitive)
Active energy: ±1% reading (0.5 inductive - 0.8 capacitive)
Frequency: ±0.05% reading ±1 digit from 45 to 65 Hz

Display and operating controls

Display: high brightness 14 mm LED display three lines, four digits (eight for energies)
Keypad: 2 push-buttons

Communication port (2)

Type: RS232 or RS485 on request, optoisolated
Baud rate: programmable from 300 to 57600 bps 78 kbps fixed, in case of LONBUS up to 12 Mbps, in case of PROFIBUS 10/100 Mbps, in case of ETHERNET on LAN side

Digital outputs

Type: 2 optoisolated (50V-100mACA-CC)

Environmental conditions

Operating temperature: from -15 °C to +60 °C
Storage temperature: from -30 °C to +75 °C
Relative humidity: 80% max. without condensation

Mechanical characteristics

Material: plastic enclosure
Protection degree: IP54 (front panel); IP20 (terminals)
Terminals: conductors 2.5 mm2
Size / weight: 96x96x60 mm or 96x96x100 mm 500 gr max, depending on the configuration

Standard compliance

Safety: 73/23/EEC and 93/68/EEC directives, EN61010.1 safety standard
EMC: 89/366/EEC directive and following modifications 93/31/EEC and 93/68/EEC, EN50081-2, EN50082-2, EN61326/A1