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Entry type: FAQ Entry ID: 8822493, Entry date: 06/28/2013

MICROMASTER 4 (MM4): Considerations when using the external 24V power supply of the MICROMASTER 4 PROFIBUS module

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This FAQ applies to MICROMASTER 4

1. Current consumption:

  • For MICROMASTER 4 up to frame size E, the rated current consumption is 350mA, and 400mA above frame size F to GX 400mA.A BOP or AOP – and all digital inputs (in the on state) - are included in this rated current consumption.   
  • An additional 100mA should be calculated for an encoder module. An added consumption of 50% must be taken into account in order to compensate for voltage fluctuations and possible power-on spikes.
  • The current consumption to be calculated is therefore between 350mA (in the most favorable case) and 750mA (in the most unfavorable case).

2. Internal connections in MICROMASTER

  • The (–) terminal of the PROFIBUS module power supply is at the same position as the isolated 0V terminal of MICROMASTER 4
    • for MICROMASTER 420, terminal 9
    • for MICROMASTER 430 and MICROMASTER 440, terminal 28
  • The (+) terminal is connected through a blocking diode with the insulated 24 V terminal. 
  • for MICROMASTER 420, terminal 8
  • for MICROMASTER 430 and MICROMASTER 440, terminal 9

3. Fault states and alarms

  • A0503 = alarm, undervoltage
    • The line supply voltage of the drive inverter is switched-out and the DP module (PROFIBUS module) is supplied through an external 24V. In this particular case, alarm message A0503 is output.
    • This alarm message can be ignored.
      • Normally, the electronics power supply is realized from the DC link of the drive inverter. The power supply is also sensed/measured via the DC link. When the drive inverter is powered-down, the electronics is supplied from the external 24V and the DC link is in a no-voltage condition. This is why A0503 is output.
  • F0003 = undervoltage & F0060 = Asic time slice overflow
  • The drive runs, the DP module (PROFIBUS module) is supplied via an external 24V supply, and the line supply (200 to 600 V AC) is disconnected. In this case, the drive is tripped with fault message F0003.
  • The line supply voltage of the drive inverter is switched-out, the DP module (PROFIBUS module) is supplied via the external 24V supply and a "run command" is issued.
  • For MICROMASTER 420 with a FW greater than 1.05, the following applies here:
    As a result of the missing line supply voltage, the control and power supply sections in the drive inverter cannot communicate with one another and F0060 is output instead of F0003.Read-only parameters may indicate incorrect values, e.g. r0037, drive inverter temperature.
  • For MICROMASTER 420 with firmware less than equal to 1.05 and MICROMASTER 440 with firmware less than, equal to 1.17, the following applies:
    Sporadically, the following fault messages can occur even if there is no fault state.
    F0001 = overcurrent
    F0002 = overvoltage
    F0003 = undervoltage
    F0004 = drive inverter overtemperature
    F0005 = drive inverter I²/t
    F0022 = HW monitoring active
    F0060 = Asic time slice overflow  
  • As soon as the line supply voltage is re-connected, these fault messages can be reset in the usual way, e.g. using bit 7 of the Profibus control word. For 500 – 600 V MICROMASTER 440, fault message F0002 can be immediately reset.

4. I/O functionality

    • With an external 24V power supply, all inputs and outputs for all versions of the MM 420 remain active.
  • For MM430 from FW2.02 and MM440 from FW2.08, all digital and analog inputs and outputs remain active; the analog inputs and outputs of frame sizes Fx**) and Gx**) are an exception.
  • For MM 430 up to FW2.02 and MM 440 up to FW2.08, there are certain restrictions regarding the function of the relay outputs and the analog inputs and outputs. The digital inputs remain active in every case.
  • If a motor PTC is connected to terminals 14 and 15 of the MICROMASTER 430 from FW2.02 onwards or MICROMASTER 440 from FW2.08 onwards, and if P0601 = 1, then when the line supply voltage is switched-out/disconnected, fault messages F0011 and F0015 are suppressed.
  • For MICROMASTER 430 up to FW2.02 and MICROMASTER 440 up to FW2.08, underthese circumstances, F0015 is output (PTC open-circuit / short-circuit). When the line supply voltage is switched-in again, the fault message can be again reset.

The actual MM4 firmware versions at the beginning when PROFIBUS modules were being supplied:

  • MICROMASTER 420: Firmware 1.05;
  • MICROMASTER 430: --------------------;
  • MICROMASTER 440: Firmware 1.16*).

 *)       Shortly after the start of production of the PROFIBUS module, the MM440 firmware
           was updated to Version 1.17.

**)     In order to achieve a reliable electronics power supply for frame sizes FX and GX,
           these should be supplied via terminal 9 instead of via the bus module.


    fuse protection X9 / 1 max. 4A

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