Senkuo SK800 Series High-Performance Low-Voltage Frequency Inverter - Vector Control Universal Inverter

Low-voltage frequency inverters adjust the motor speed to make the motor always operate at the optimal efficiency point, avoiding energy waste caused by traditional fixed-speed motors adjusting flow through valves, dampers, etc. For fan and pump loads, using low-voltage frequency inverters for speed regulation can save 30%-60% of electrical energy; for constant torque loads, it can also save 10%-20% of electrical energy by optimizing motor operation status.

When selecting a low-voltage frequency inverter model, focus on three core dimensions: ① Power matching: Prioritize selection based on low-voltage frequency inverter rated current ≥ motor rated current × 1.1-1.2 times, rather than just comparing power values; ② Load characteristics: Constant torque loads (such as conveyors, extruders) require models with rated current slightly larger than the motor, while variable torque loads (such as fans, pumps) can be selected one power level lower; ③ Application environment: For high temperature (above 40°C), high altitude (derate 10% for every 1km increase), or high-frequency start-up scenarios (such as injection molding machines), it is recommended to select a larger power model.

Low-voltage frequency inverters and soft starters are both motor control equipment, but with different functions: ① Soft starters are only used in the motor start-up phase to achieve smooth start-up and need to exit operation after start-up; ② Low-voltage frequency inverters can control the motor speed throughout the process to achieve stepless speed regulation, suitable for scenarios that require speed adjustment. In addition, low-voltage frequency inverters have energy-saving functions, while soft starters do not.

It is strictly prohibited to connect low-voltage frequency inverters to power supplies higher than their rated voltage, which will directly cause internal components to burn; when low-voltage frequency inverters are connected to low-voltage power supplies, it is necessary to first confirm the minimum operating voltage range of the product, and the output power will be limited proportionally. It is recommended to first select low-voltage frequency inverter models with completely matching voltage levels.

① V/F control: Economical and simple, suitable for ordinary fans, pumps and other loads with low precision requirements, with control accuracy of about 1-2%; ② Open-loop vector control: Stronger low-speed torque, suitable for occasions with large load fluctuations (such as mixers); ③ Closed-loop vector control: Control accuracy < 0.5%, supporting 200% rated torque at 0Hz, suitable for high-precision demand scenarios such as CNC machine tools and precision processing.

Low-voltage frequency inverter installation needs to meet the following conditions: ① Temperature: -10°C~40°C, derate 1% for every 1°C increase above 40°C; ② Humidity: 20%-90% RH, no condensation; ③ Space: Reserve sufficient heat dissipation space above and below (spacing ≥ 30cm for models above 30kW); ④ Environment: Clean, dust-free, no corrosive gases, no severe vibration.

① Power connection: Three-phase power is connected to R/S/T terminals (no phase sequence requirements), and single-phase power is connected according to the terminals specified in the manual; ② Motor connection: U/V/W terminals are connected to the motor, and the phase sequence needs to be confirmed to ensure the motor forward and reverse rotation meet requirements; ③ Grounding requirements: Low-voltage frequency inverters and motors need to be grounded independently (series connection is prohibited), with grounding resistance < 4Ω; ④ Anti-interference: Control lines and power lines should be at least 30cm apart, and arranged at 90° when crossing.

Common faults of low-voltage frequency inverters include: ① Overcurrent: Check if the motor is overloaded, wiring is correct, and load is stuck; ② Overvoltage: Check if the grid voltage is too high and deceleration time is too short; ③ Overheating: Check if ventilation is good, ambient temperature is too high, and fan is running normally; ④ Undervoltage: Check if the grid voltage is too low and power capacity is sufficient. Troubleshooting methods include adjusting parameters, checking wiring, cleaning vents, replacing fans, etc.

The maintenance cycle of low-voltage frequency inverters depends on the usage environment and load conditions: ① Under normal conditions, routine maintenance is recommended every 6 months, including cleaning vents, checking terminals, testing insulation resistance, etc.; ② In harsh environments (such as high temperature, high dust), maintenance is recommended every 3 months; ③ For important equipment in continuous operation, inspection is recommended every month.

It is not recommended to connect contactors to the output end of low-voltage frequency inverters. Switching contactors during operation will cause low-voltage frequency inverters to trip due to overcurrent, and severely damage internal inverter modules. If load switching is required, it should be operated after the low-voltage frequency inverter stops.