Pool Main Pump Motor: Difference between revisions
→Theory of Operation
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=== Theory of Operation === | === Theory of Operation === | ||
<i>The sections below are theoretical at this point, describing possible operation for the VFD controls.</i> | |||
==== Run ==== | ==== Run ==== | ||
Pressing the <b>Run</b> pushbutton causes the VFD digital input (FWD/DI1) to go HIGH (+24V). Assuming the safety module is reset, the VFD will | Pressing the <b>Run</b> pushbutton causes the VFD digital input (FWD/DI1) to go HIGH (+24V). Assuming the safety module is reset, the VFD will ramp up to full speed (60 Hz). The speed may be reduced via closed-loop control from the automation system (based upon flow meter feedback). By defaulting to 60 Hz, the motor can be operated normally without the automation system, using the butterfly valve on the output side of the pump to adjust flow. | ||
A VFD digital output (DO1) illuminates the green LED embedded in the <b>Run</b> pushbutton. | |||
==== Stop ==== | |||
Pressing the <b>Stop</b> pushbutton causes the VFD digital input (DI3) to go LOW (no longer connected to +24V). The VFD will ramp down to zero speed. | |||
A | A switch guard (cover) may be placed on the stop button to deter its use (in favor of <b>Programmed Stop</b>). In an emergency, the <b>Emergency Stop</b> pushbutton can still be easily accessed. | ||
==== Programmed Stop ==== | ==== Programmed Stop ==== | ||
Pressing the <b>Programmed Stop</b> pushbutton notifies the PLC (automation system) that a pump stop is requested. The pump may not stop immediately; this pushbutton is not connected to the VFD. Instead, if the boiler is operating, it is disabled and allowed to cool. Once the boiler has cooled sufficiently, the pump is stopped. | |||
An indicator in the <b>Programmed Stop</b> pushbutton blinks periodically during the period between when the button is pushed and the pump motor is stopped. Pressing the button repeatedly has no effect; the programmed stop cannot be canceled. When desired, the user may press the <b>Run</b> pushbutton to resume pump motor operation. | |||
==== Emergency Stop ==== | ==== Emergency Stop ==== | ||