Before installing the inverter, the installation environment must be determined, and then a suitable installation method should be used. When wiring the inverter, the main circuit and control circuit must be correctly wired. Let’s take a closer look.

1. Installation environment of the inverter

1)Ambient temperature: -10℃~40℃;

2) Environmental humidity: relative humidity does not exceed 90% (no condensation);

3) Other conditions: No direct sunlight, no corrosive gases and flammable gases, little dust, and the altitude is less than 1000m.

2. How to install the inverter

(1) Wall-mounted installation: The distance between the inverter and surrounding objects should meet the conditions: ≥100mm on both sides and ≥150mm on the top and bottom;

(2) Cabinet installation: When installing a single frequency converter, the cooling method outside the cabinet should be used as much as possible (when the environment is relatively clean and there is little dust); when a single frequency converter adopts the cooling method inside the cabinet, an exhaust cooling fan should be installed on the top of the cabinet, and Try to install it directly above the frequency converter; multiple frequency converters should be installed side by side as much as possible. If it must be installed vertically, a partition should be installed between the two frequency converters. Either way, the frequency converter should be installed vertically.

Installation and Wiring Requirements for vfd

3. Conditions of use:

1: The operating temperature of the inverter is mostly: 0 ~ 40 degrees Celsius or -10 ~ 50 degrees Celsius. Pay attention to the ventilation of the inverter cabinet.

2: The ambient humidity of the frequency converter is lower than 90%. If the surrounding humidity is too high, there will be problems such as reduced electrical connections and corrosion of metal parts. Restricted by the installation location, the inverter cabinet should be sealed as much as possible in locations where the inverter is installed with high humidity. To prevent condensation when the frequency converter is stopped, the unit needs to be equipped with a convection heater.

3: There should be corrosive, explosive or flammable gases, dust and oil mist around the inverter. If there are explosive and flammable gases around the inverter, there will be relays and contactors in the inverter that are prone to sparks, which may cause fire or explosion accidents. When there is corrosive gas, the metal parts will corrode, affecting the long-term operation of the inverter. When there is dust and oil mist around the frequency converter, the adhesion and accumulation of these gases will cause the frequency converter to reduce its adhesion; forced air-cooled frequency converters, filter clogging will cause the temperature of the frequency converter to rise abnormally, causing the frequency converter to become unstable. run.

4: The vibration resistance of the frequency converter varies from machine to machine. When the vibration exceeds the allowable value of the frequency converter, the fastening parts of the components will loosen, and movable parts such as relays and contactors will malfunction, often resulting in the stable operation of the frequency converter. In situations such as machine tools and ships where vibration can be predicted in advance, inverter vibration should be considered.

5: The inverter is above 1000 meters above sea level. High altitude and low air pressure can easily cause bonding damage. In addition, the cooling effect decreases with increasing altitude, so temperature rise must be paid attention to.

Inverter wiring:

When various factory equipment uses variable frequency speed regulation, harmonic interference will occur on the power supply side and motor side of the frequency converter, and EMC interference will occur in the power supply grid and other electrical equipment around the frequency converter. In addition, in order to ensure the long-term reliable operation of the frequency converter, the wiring of the frequency converter is very important.

  • 1. Main circuit wiring

(1) The inverter input (R, S, T) and output (U, V, W) must not be connected incorrectly;

(2) Main circuit path selection
①The power supply and inverter wiring are the same as the wire diameter selection methods for motors of the same capacity;
② The line voltage drop △U must be considered for the wiring between the inverter and the motor. The general requirements are: △U≤(2~3)%Un. The calculation formula of △U is: (not copied) where: Imn – rated current of the motor ( A) R0 – resistance of wire per unit length (per meter) (mΩ/m),

L – length of wire (m) Nominal cross-sectional area / 1.0 1.5 2.5 4.0 6.0 10.0 16.0 25.0 35.0 / (mΩ/m) 17.8 11.9 6.92 4.40 2.92 1.73 1.10 0.69 0.49

  • 2. Wiring of control circuit

(1) The analog control line should use a shielded wire, with one end of the shield connected to the common terminal (COM) of the inverter control circuit, not connected to the ground terminal (E) of the inverter or the earth, and the other end left floating.
(2) Switching control lines are not allowed to use shielded wires, but two wires of the same signal must be twisted together.

Before installing the inverter, the installation environment must be determined, and then a suitable installation method should be used. When wiring the inverter, the main circuit and control circuit must be correctly wired. Let’s take a closer look.

1. Installation environment of the inverter

1)Ambient temperature: -10℃~40℃;

2) Environmental humidity: relative humidity does not exceed 90% (no condensation);

3) Other conditions: No direct sunlight, no corrosive gases and flammable gases, little dust, and the altitude is less than 1000m.

2. How to install the inverter

(1) Wall-mounted installation: The distance between the inverter and surrounding objects should meet the conditions: ≥100mm on both sides and ≥150mm on the top and bottom;

(2) Cabinet installation: When installing a single frequency converter, the cooling method outside the cabinet should be used as much as possible (when the environment is relatively clean and there is little dust); when a single frequency converter adopts the cooling method inside the cabinet, an exhaust cooling fan should be installed on the top of the cabinet, and Try to install it directly above the frequency converter; multiple frequency converters should be installed side by side as much as possible. If it must be installed vertically, a partition should be installed between the two frequency converters. Either way, the frequency converter should be installed vertically.

Installation and Wiring Requirements for vfd

3. Conditions of use:

1: The operating temperature of the inverter is mostly: 0 ~ 40 degrees Celsius or -10 ~ 50 degrees Celsius. Pay attention to the ventilation of the inverter cabinet.

2: The ambient humidity of the frequency converter is lower than 90%. If the surrounding humidity is too high, there will be problems such as reduced electrical connections and corrosion of metal parts. Restricted by the installation location, the inverter cabinet should be sealed as much as possible in locations where the inverter is installed with high humidity. To prevent condensation when the frequency converter is stopped, the unit needs to be equipped with a convection heater.

3: There should be corrosive, explosive or flammable gases, dust and oil mist around the inverter. If there are explosive and flammable gases around the inverter, there will be relays and contactors in the inverter that are prone to sparks, which may cause fire or explosion accidents. When there is corrosive gas, the metal parts will corrode, affecting the long-term operation of the inverter. When there is dust and oil mist around the frequency converter, the adhesion and accumulation of these gases will cause the frequency converter to reduce its adhesion; forced air-cooled frequency converters, filter clogging will cause the temperature of the frequency converter to rise abnormally, causing the frequency converter to become unstable. run.

4: The vibration resistance of the frequency converter varies from machine to machine. When the vibration exceeds the allowable value of the frequency converter, the fastening parts of the components will loosen, and movable parts such as relays and contactors will malfunction, often resulting in the stable operation of the frequency converter. In situations such as machine tools and ships where vibration can be predicted in advance, inverter vibration should be considered.

5: The inverter is above 1000 meters above sea level. High altitude and low air pressure can easily cause bonding damage. In addition, the cooling effect decreases with increasing altitude, so temperature rise must be paid attention to.

Inverter wiring:

When various factory equipment uses variable frequency speed regulation, harmonic interference will occur on the power supply side and motor side of the frequency converter, and EMC interference will occur in the power supply grid and other electrical equipment around the frequency converter. In addition, in order to ensure the long-term reliable operation of the frequency converter, the wiring of the frequency converter is very important.

  • 1. Main circuit wiring

(1) The inverter input (R, S, T) and output (U, V, W) must not be connected incorrectly;

(2) Main circuit path selection
①The power supply and inverter wiring are the same as the wire diameter selection methods for motors of the same capacity;
② The line voltage drop △U must be considered for the wiring between the inverter and the motor. The general requirements are: △U≤(2~3)%Un. The calculation formula of △U is: (not copied) where: Imn – rated current of the motor ( A) R0 – resistance of wire per unit length (per meter) (mΩ/m),

L – length of wire (m) Nominal cross-sectional area / 1.0 1.5 2.5 4.0 6.0 10.0 16.0 25.0 35.0 / (mΩ/m) 17.8 11.9 6.92 4.40 2.92 1.73 1.10 0.69 0.49

  • 2. Wiring of control circuit

(1) The analog control line should use a shielded wire, with one end of the shield connected to the common terminal (COM) of the inverter control circuit, not connected to the ground terminal (E) of the inverter or the earth, and the other end left floating.
(2) Switching control lines are not allowed to use shielded wires, but two wires of the same signal must be twisted together.

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