Real Applications | International English |
7.1.3Key Parameter Details
Table
Number | Value | Meaning | ||
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P1000 | 1 | Motorised potentiometer enabled. This allows the push buttons on the AOP to | ||
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| be used to control the speed. | |
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P0003 | 3 | Allows all parameters to be adjusted and set. | ||
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P1031 | 1 | Motorised potentiometer settings stored on power down. The inverter will | ||
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| restart at the previous selected frequency. | |
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P1200 | 34 | Flying Start in forward direction enabled. This ensures that if the fan is rotating | ||
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| the inverter will sense it’s speed and ramp back to the desired speed. | |
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P1300 | 2 | Quadratic V/F curve selected. Selecting the quadratic curve allows a higher | ||
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| continuous output, but limits the overload capability, which is not needed in this | |
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| case. The quadratic curve also reduces the power consumption because it is | |
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| optimised for fan and pump applications. | |
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P1055 | 0 | Jog Key disabled | ||
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P1032 | 1 | Reverse direction disabled | ||
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Note.
The default settings of minimum and maximum speeds (0 – 50 Hz) are used in this case.
All required information such as speed, current and drive status is on the display.
If resonance is experienced in the system, it can be suppressed by using the skip frequency settings P1091- 1094.
7.2A Closed Loop Controller using a Fan
The application uses an 11 kW MICROMASTER driving an 11 kW motor which operates the extractor fan in a chemical plant. The extractor maintains a constant flow rate by measuring flow downstream of a burner system. The MICROMASTER is installed in a cubicle close to the fan system, and a simple run/ stop signal used for control. The flow sensor is connected to the analog input to supply the necessary feedback signal. A resistor is fitted to the input to convert the current source to a voltage signal (2 to 10 V).
7.2.1Advantages
·Very significant energy savings compared with fixed speed running.
·Improved process control - in this case, reduced pollution as burner operates at maximum efficiency.
·Built in PI means no additional controllers etc.
·No manual adjustment needed; simple run/stop commands.
36 | MICROMASTER Applications Handbook |