How to wire two-location control for an inverter
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The frequency converter is equipped with an operation panel on site, which allows for switching between mains frequency and variable frequency to control the increase or decrease of the frequency. How can operations at the DCS end be used to start and stop the motor as well as to adjust the frequency? The frequency converter is the Inovance IPE200 series
Are you saying that frequency conversion can be performed on-site at the control column, but when switching to remote mode, it is the DCS that handles the frequency conversion?
This post was last edited by Others on 2019-3-1 15:51. Yes. The problem is that the inverter currently has only one 4-20ma input
There should also be a 4–20mA output, which will be sufficient.
This post was last edited by Others on 2019-3-2 07:28. There is a 0-20ma output signal – how should it be wired? Please give your advice
This post was last edited by ikqinqye on 2019-3-2 at 18:21. Treat it as an electric valve: the DCS sends signals to the frequency converter, the frequency converter sends feedback signals to the DCS, and a manual operator is installed on the DCS. I haven’t used your frequency converter, but I use them this way with frequency converters from Siemens and Vecor as well. Of course, the frequency converter needs to be configured; the instructions are available in the manual.
The diagram you provided shows two AI circuits: AI1 is connected to +10V, and GND can be connected to a potentiometer to enable adjustment from 1-10V; AI2 is connected to GND and can be fed with an external signal of 0-10V or 4-20mA, depending on the selection made via jumper J18. Then, via a DI line, AI1 and AI2 are set internally in the inverter for switching.
It is estimated that this needs to be implemented in conjunction with a control system; first, on-site, there must be local and remote rotation switch buttons. When local mode is selected, the system accepts the on-site speed control signals and sends them to the frequency converter via the DCS or PLC AO cards. When remote mode is selected, the system uses soft signals from the indoor control panel to send the signals to the frequency converter through the DCS or PLC AO cards. In short, there is only one source of control signal for the inverter’s output, but it is necessary to ensure proper tracking within the system in order to avoid signal disturbances during switching.
I guess your on-site control function is used while driving, to facilitate real-time monitoring by the driver.