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Simple Applications

Advanced Features:

025Enable DC brake. The DC brake feature can be enabled to provide a holding torque if required. See section 8.2.

013/014 Increase/decrease frequency (Motor Potentiometer function).

099BiCo Functionality. Many complex functions are possible. Please consult the Parameter List for additional details.

Output Frequency

Alternate Ramp time selected via digital input

DC Braking

selected via digital input

Fixed Frequencies

Time

Possible control cycle using fixed frequencies, DC Braking, and Variable Ramp Rates

Figure 5-3 Composite Control Cycle

5.5Using the control outputs

There are several control outputs, which can be used to control external indicators or warn of potential problems.

5.5.1Analog Output (MICROMASTER MM440 only).

The analog output may be set to give several different indications as described in parameter P0771. The output is 0-20 mA, but can be easily converted to a voltage by fitting a resistor (500 ohms for 0-10 V for instance), and to 4-20 mA using the scaling parameters such as P0778.

5.5.2Relays

An indicator relay is provided which may be programmed to give a variety of indications using parameter P0731. The relay is often used to indicate set point reached (P731=52.8), warning active (P731=52.7), output current exceeding a set value (P731=53.3).

The relays can be used to control an external brake. A timer function can be used to start the inverter and release the brake as described in parameter P1216. In this case, the relay must be suppressed and a contactor used to switch the brake itself. See section 5.8.6.

The relay contacts should be suppressed where inductive loads such as contactor coils or electromagnetic brakes are switched.

MICROMASTER Applications Handbook

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