M850-LTHN Multifunction Power Meters

M850-LTHN Multifunction Power Meters


The new range of Hobut power meters feature 96 x 96mm moulded cases and selectable three colour backlight LCD screens. The range is easy to use, features user-programmable CT & VT ratios, and can be used on any single or 3 phase system with any input voltage with programming.


The range is a cost effective replacement for traditional panel meters and is suitable for low, medium and high voltage control panels, gensets, building management systems, power management and more.

Standard Functions:

  • Phase Voltage (V)
  • Phase to Neutral Voltage (V)
  • Phase Current (I)
  • Frequency (Hz)
  • Active Power (W)
  • Active Energy (kWh)
  • Reactive Power (VAr)
  • Apparent Power (VA)
  • Reactive Energy (VArh)
  • Power Factor (PF)
  • Instantaneous Amp Demand
  • Instantaneous Watt Demand
  • Instantaneous VA Demand
  • Maximum Amp Demand
  • Maximum Watt Demand
  • Maximum VA Demand
  • Neutral Current
  • THD Current
  • THD Voltage

CONTROLS: 4 front buttons are used for scrolling through parameters and programming
DISPLAY: A unique large custom LCD, with 3 user-programmable colour options
COMMUNICATIONS: An optional RS485 port allows communication via Modbus RTU or BACNET (MSTP) protocol
PULSED OUTPUT: A relay output can be assigned to either W.h or Var.h
INSTALLATION: Supplied with installation guide or download complete installation manual and RS485 Modbus register address at www.hobut.co.uk/power-meters

All models feature the following user-programmable functions:

  • Selectable Screen Colour
  • Current Transformer Ratio
  • Voltage Transformer Ratio
  • Baud Rate, Parity, Stops
  • Single or 3 phase system
  • Input voltage range 28-570V
  • RS485 address, 1-247
  • Security code access for programming

Ordering Information


Volts/Amps: 0.5% of reading
Frequency: 0.1 Hz
Active Power: 1% of reading
Apparent Power: 1% of reading
Power Factor: 1% of range
Energy: IEC 1036 Class 1
Rated Un: 28-330V LN, 48-570V L-L
Overload: 800V continuous
Burden: 0.5VA per phase
Rated In: 0.5-6A (5A nominal)
Overload: 10 In for 1 sec
Burden: 0.5VA per phase
Auxiliary: 100-440V AC / 100-420V DC
(or 19/69V DC)
Frequency: 45/65Hz
Digits: 3 Lines of 9999 (7 segment 14.2mm)
1 line of 99999999 (7 segment 6mm)
Custom LCD
Brightness: User adjustable
Wh or VArh: SPNO rated 50V
Pulse output: 150mA 5W AC/DC
Pulse duration: Programmable from 40msec-200msec
Installation category: III (480 V AC ph/ph)
Degree of pollution: 2
Rated impulse withstand voltage: IEC 60947-1-V imp: 4kV
Meters front: Class II
Electrical security: IEC 61010-1
Inputs + Aux to case: 4kV rms 50Hz for 1 min
Inputs + Aux to RS485 port: 3kV rms 50Hz for 1 min
Inputs + Aux to relay output: 1k5V rms 50Hz for 1 min
Low voltage dc Aux to Inputs: 1k5V rms 50Hz for 1 min
Immunity to:
electrostatic discharges: IEC 61000-4-2-Level III
radiated radio-Hz fields: IEC 61000-4-3-Level III
electrical fast transient/brusts: IEC 61000-4-4-Level III
impulse waves: IEC 61000-4-5-Level III
conducted disturbances: IEC 61000-4-6-Level III
voltage dips & short interruptions: IEC 61000-4-11
Emissions to:
conducted and radiated: CISPR11-Class A
Working temp: -20 to +70ºC
Storage temp: -40 to +85ºC
Relative humidity: 0-95% non condensing
Shock: 30G in 2 planes
Black polycarbonate case to UL94V0
Weight: 0.3kg
IP Rating: IP52 (front)

Connection Diagram

Dimensions (mm)

Dimensions (mm)

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