International English

Simple Applications

5 Applications and Possibilities

Most inverters used in industry are controlled via the control terminals, not the front panel. This section describes some simple control possibilities using these inputs, and some of the programmable features that may prove useful. The following descriptions include terminal numbers and parameter values which are valid for MICROMASTER MM420 inverters. If other products are used please check the terminal numbers in the Reference Manual supplied with the inverter.

5.1Using a Potentiometer with the Analog Input

Connect a potentiometer (between 5 kΩ and 100 kΩ) to the analog input as shown in Figure 5-1. The Potentiometer is wired as shown:

MICROMASTER

 

1

Potentiometer

2

Connection

3

 

4

5DIN 1

8+24 V Output

Figure 5-1 Using a Potentiometer with the Analog Input

Connect a switch between terminals 5 and 8 in order to apply a ‘RUN’ command to digital input 1.(DIN 1) The default parameter settings of the MM420 will permit operation using this simple arrangement.

The default maximum and minimum settings for the analog input are 50 and 0 Hz respectively, so the inverter will run at a frequency somewhere between these frequencies, depending on the potentiometer position.

Changing parameters such as P0758 and P0760 will change the range of the potentiometer accordingly, but remember the absolute maximum and minimum settings are set by parameters P1080 and P1082. Note that many parameters cannot be changed while the inverter is running. The display will flash if this is attempted.

5.2Using all the Digital Inputs

The digital inputs on the inverter are programmable and many different functions can be selected. The digital inputs have default settings which are used below, but can be easily changed.

With the potentiometer still connected, connect two more switches as shown below. The first switch will run the inverter as before, the second switch will now reverse the direction (providing a ‘RUN’ signal is already present from the first switch. The third switch can be used to reset any faults should they occur. These are the default settings for controlling the MICROMASTER MM420.

MICROMASTER Applications Handbook

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