ST500 | Frequency converter as pump control – Parameter list for pressure control
Note: Unchanged factory settings (except motor parameters) are assumed.
Programmed values
| Parameter | Value | Functional description |
| F0.03 | 8 | PID control |
| F0.11 | 4 | 4: All control sources (control panel, control terminals, interface) |
| F0.13 | 10 | Acceleration time 1 – adjust during commissioning if necessary |
| F0.14 | 10 | Braking time 1 – adjust during commissioning if necessary |
| F1.16 | 2 | Minimum voltage at AI2: 2V corresponds to 4mA corresponds to 0%. |
| F1.42 | 1,00 | Setting range of the rotary encoder 100 steps from 0 to 100%.
or from 0.0bar to 10.0bar |
| F1.44 | 0,00 | Minimum value control panel rotary encoder |
| F1.45 | 100,00 | Maximum value control panel rotary encoder |
| F6.16 | d0.16 | Lower display line:
d0.09 Voltage at AI1 after correction by F1.16-F1.19 d0.16 PID feedback variable scaled with E2.04 |
| F7.17 | 1 | Reverse operation blocked |
| F7.46 | 20 | Inverter only wakes up again when the PID controller would run the pump at >20Hz |
| F7.47 | 0 | Waiting time for F7.46 |
| F7.48 | 15 | Inverter goes into sleep mode if the PID controller wants to run the pump at <15Hz for longer than F7.49 |
| F7.49 | 2 | Waiting time for 7.48 |
| FC.02 | 5 | Start deviation 5% from setpoint |
| E2.00 | 3 | PID setpoint: Control panel rotary encoder |
| E2.02 | 1 | Feedback variable: analogue signal 4..20mA at AI2 |
| E2.04 | 10 | Scaling for the display in d0.16: At 100% this value is displayed, corresponding to 10bar |
| E2.06 | 2 | PID deviation limit |
| E2.27 | 1 | Continue PID calculation in stopped state |
| Y0.00 | 12 | Upload the previously set parameters to control panel memory location 2 for later restoration (see below). |
Italics: Factory setting, listed for illustrative purposes only
Motor parameters
| Parameter | Value 4kW | Functional description |
| B0.01 | Nominal engine power in kW | |
| B0.02 | Nominal motor voltage in V | |
| B0.03 | Rated motor current in A | |
| B0.04 | Nominal motor frequency in Hz | |
| B0.05 | Nominal engine speed in rpm – for display purposes only |
For V/f control, entering the motor parameters is not mandatory, but is recommended to enable the inverter’s motor protection functions.
In case of problems
| Parameter | Value | Functional description |
| Y0.00 | 22 | Downloading the set parameters from control panel memory location 2 |
For a detailed explanation of the individual function of the parameters, please consult the manual.
Terminal assignment
| Sourcetronic ST500 |
Functional description |
| R | Mains to supply or main switch |
| S | |
| T | |
| PE | |
| U | Motor directly at the FI |
| V | |
| W | |
| PE | |
| +24V | Together with COM voltage source e.g. for signal lamp (max. 200mA minus sensor).
The +Ub connection of the pressure sensor is connected here. |
| COM | Common contact digital inputs DI1-DI8 |
| DI1 | On: Start forward with ramp F0.13 in control mode; Off: Brake with ramp F0.14 |
| GND | Must be bridged with COM so that the 24V source can be used for the sensor at the (normally potential-separated) analogue input |
| AI2 | The GND connection of the pressure sensor is connected here. |
| TC1 | Relay 1: TC1 – TA1 closed if an error has occurred.
Otherwise TC1 – TB1 closed |
| TA1 | |
| TB1 | |
| TC2 | Relay 2: TC2-TA2 closed when FI in operation
Connection option for e.g. operating lamp |
| TA2 |
Commissioning
The connections R, S, T of the frequency inverter are connected to the mains directly behind the main switch, the motor in the star to the connections U, V, W of the inverter.
The pressure sensor is connected as follows:
+Ub to terminal 24V
GND to terminal AI2
In addition, a jumper from COM to GND must be set on the inverter.
The rotary encoder has a basic resolution of 0.01% per step (without acceleration setting in). In the setting F1.42=1.00 there are exactly 100 steps from 0 to 100%. The factory setting of 0.50 would be 50 steps. With parameters F1.44 and F1.45, the value range can be limited if necessary, e.g. with F1.44=40.00 and F1.45=65.00 to 40-65% corresponding to 4.0 to 6.5bar, still in the same number of steps.
The start switch is connected between DI1 and COM of the inverter. As soon as the start switch is closed or the start button on the control panel is pressed, the inverter starts PID control. When the start switch is opened or the stop button on the control panel is pressed, the inverter stops.
Relay 1 switches from TB1/TC1 to TA1/TC1 in the event of a fault.
Relay 2 of the inverter (TC2/TA2) can be used to control an operating light, for example. If the internal 24V source is used for this, the lamp and pressure sensor together must not draw more than 200mA.
If the target frequency falls below 15Hz for more than 2 seconds, the inverter goes to sleep. If the target frequency exceeds 20Hz and the deviation from the target value is greater than 5%, the inverter continues operation. Depending on the dynamics of the piping system, it may be necessary to adjust the setting values for FC.02, E2.06 and F7.46-49.
If the pump has specified a minimum frequency, this should be used for F7.48 and F7.46 should be adjusted accordingly.
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