1. Precautions for Using Permanent Magnet Variable Frequency Household Pumps
1. Before starting the pump, open the inlet valve first. Start the pump immediately after opening the inlet valve.
2. The pump requires clean tap water with a pressure of 1–1.5 × 10⁵ Pa for operation. If water pressure is normal, fully open the water valve. If water pressure is high, adjust the inlet valve to control water flow.
3. Water ring vacuum pumps require supplementary water. Maintain a reasonable water supply—insufficient water reduces pump performance, while excessive water not only degrades performance but may overload the motor.
4. Before stopping the pump, close the inlet valve. Then introduce high-pressure gas into the inlet port to expel most of the water from the pump before shutting down.
5. Monitor current levels during operation. If a sudden surge occurs, immediately shut down the pump for inspection. If water leakage is detected from the square hole beneath the pump's base during operation, stop the pump for maintenance. Ensure no foreign objects block the exhaust pipe during operation; if detected, stop the pump immediately to clear the obstruction.
6. If the vacuum pump is not used for an extended period, drain all accumulated water from the pump.
7. Before restarting after a long shutdown, remove the motor guard and manually rotate the motor fan blades until they turn freely before starting the pump.
2. What are variable constant pressure, constant variable pressure, variable variable pressure, and how are these functions achieved?
Variable Constant Pressure, Constant Flow Variable Pressure, and Variable Flow Variable Pressure primarily refer to the flow and pressure conditions measured at the equipment's outlet. “Variable” denotes change, “Constant” denotes stability, ‘Flow’ refers to flow rate, and “Pressure” refers to pressure. To understand these concepts, one must first grasp the definitions above. Their implementation principles primarily differ in control points and control methods.
① Variable Flow Constant Pressure: Regardless of water consumption fluctuations, the outlet pressure remains constant. The constant pressure control point is located at the equipment outlet.
② Constant Volume Variable Pressure: The equipment delivers a constant water volume, but pressure fluctuates with changes in water consumption. This control method is typically used in large water treatment plants and pumping stations. Equipment supplies water based on average hourly consumption. When water demand increases, pipeline pressure naturally rises; when demand decreases, pipeline pressure naturally drops.
③ Variable Flow and Variable Pressure: Both flow rate and pressure at the outlet fluctuate in response to changes in water demand. When monitoring at the outlet, both flow and pressure values change simultaneously.
