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NMTP - POWER converter AC

The NMTP AC power converters with two mutually independent analogous outputs serve to convert single-phase or three-phase AC power into current or voltage analog signals. The A output is used for active power measurements, the B output for reactive power measurements. 

To order the devices as contact us at: mcu@metra.cz

More details


The NMTP AC power converters with two mutually independent analogous outputs serve to convert single-phase or three-phase AC power into current or voltage analog signals. The A output is used for active power measurements, the B output for reactive power measurements. In such a way significant savings of installation place can be achieved.

All current inputs are electrically isolated from the outputs, from the power supply unit and from each other. The rated input current may be independently set according to user´s requirements, within a range from 1A to 5A.

The voltage inputs are electrically isolated from the outputs and from the power supply. Voltage dividers at the input are connected to the ground potential of the N conductor. The rated input voltage can be chosen from 57.7 V to 500 V.

The outputs of the converter provide DC current or DC voltage signals of a freely selectable range. In addition to standard values the output quantities can be set as required to up to 20 mA or 10 V, at maximum.

The converter is equipped with a cutting-edge power supply unit, capable of processing auxiliary power supply voltages ranging from 24 V to 230 V, both DC and AC of 50 or 60 Hz frequency.

The NMTP converters are installed in a plastic case equipped with clamping device to fix the converter individually to a DIN 46 277 (35mm) rail. The terminal block provides for the connection of 0.5 to 4 mm2 conductors pushed-in into connectors installed at the opposite side of the instrument housing.



  • power supply voltage:                                   20V to 300V  DC, or

24V to 260V AC, 50 Hz (60Hz)

  • power consumption                                                   3 W at fully loaded outputs
  • frequency of current and voltage                  45 to 65 Hz
  • accuracy of power measurement                   0.2 % Pn (of rated power)

*) 0,5 % Pn for rated output quantity values I<10mA, U<5V

  • number of current measuring inputs              1 to 3
  • rated input current  In                                   selectable within a range of 1 A to 5 A
  • input current range                                        0 to 1.2 In      
  • input overload capacity    

permanent                                                      1.2x In

short-time                                                      20x In /1 s

  • number of voltage inputs                               1 to 3
  • rated input voltage selectable from               57.7 V to 500 V
  • overload capacity of voltage inputs    

-          permanent                                    120% of Un rated voltage

-          short-time                                    200% of Un during ! second

  • analogous outputs                              2

-       current outputs                            0...20mA; 4...20 mA;   -20...0...+20mA

  • or on order                                   0…x mA (x= 5 to 20 mA)

-       voltage outputs                            0...10 V

  • or on order                                   0…x V (x= 1 to 10 V)
  • rated burden at the output

-       voltage output                             Run = Uan / 2mA

-       current output                             Rin = 5 V/ Ian

(Ian = rated output current)

  • permissible load range

-       voltage output                              Ru higher than 0.25 Run

-       current output                              resistance Ri of the loop less than 2xRin

  • highest output voltage                                   ±13V DC
  • settling time of the output [0/90%]  100ms

    (response time to unit-pulse signal 0 -> 100% of rated input value)

  • settling time after power supply connection:            1 minute
  • dielectric strength (acc. to ČSN EN 61010-1 )

-       inputs to outputs                                      3700V, 50Hz/1min

-       inputs to power supply                            3700V, 50Hz/1min

-       inputs to auxiliary power supply                         3700V, 50Hz/1min

-       terminals to the case                                3700V, 50Hz/1min

-       between the inputs                                             1000 V, 50 Hz/min

  • material of the case                                       PC/ABS
  • weight                                                           max. 200 g
  • dimensions                                                    101x114x35 mm
  • operating temperature range                          -25 to +70°C
  • error caused by ambient temperature  

max. ±0.1%/10°C  to ČSN EN 606 88, within the range of –25°C to +55°C (+ auxiliary error caused by ambient temperature of 0.2% within +55°C to +80°C)

  • operating position                                          any desired
  • protection degree                                          IP 20
    • electromagnetic compatibility           emission: acc. to ČSN EN 55011-B

immunity to industrial environments: acc. to ČSN EN 6100-6-2, ed.3


Safety in accordance with ČSN EN 61010 – 1 standard; usage group (protection class) II, appliance class (overvoltage category) III (highest operating voltage to earth: 300Vrms), pollution degree 2


manufacturer:          METRA BLANSKO s.r.o.    Company reg. No. (IČ): 02356180

Pražská 7, house No. 2536    Tax reg. No. (DIČ): CZ02356180

678 01 Blansko , Czech Republic     Web: www.metra.cz


To order the devices assemble code on website www.metra.cz, or contact us at: mcu@metra.cz

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