Only little maintenance is required when the VFD is installed in an environment that meets the requirements. The following table describes the routine maintenance periods recommended by INVT.
Subject | Item | Method | Criterion | |
Ambient environment | Check the temperature, and humidity, and whether there is vibration, dust, gas, oil spray, and water droplets in the environment. | Visual inspection, and use instruments for measurement. | The requirements stated in this manual are met. | |
Check whether there are foreign matters, such as tools, or dangerous substances placed nearby. | Visual inspection | There are no tools or dangerous substances placed nearby. | ||
Voltage | Check the voltage of the main circuit and control circuit. | Use multimeters or other instruments for measurement. | The requirements stated in this manual are met. | |
Keypad | Check the display of information. | Visual inspection | The characters are displayed properly. | |
Check whether characters are not completely displayed. | Visual inspection | The requirements stated in this manual are met. | ||
Main circuit | Common | Check whether the bolts loose or come off. | Screw them up. | No exception occurs. |
Check whether the machine is deformed, cracked, or damaged, or their color changes due to overheating and aging. | Visual inspection | No exception occurs. | ||
Check whether there are stains and dust attached. | Visual inspection | No exception occurs. Note: Discoloration of copper bars does not mean that they cannot work properly. | ||
Conductor and wire | Check whether the conductors are deformed or their color change due to overheat. | Visual inspection | No exception occurs. | |
Check whether the wire sheaths are cracked or their color changes. | Visual inspection | No exception occurs. | ||
Terminal block | Check whether there is damage. | Visual inspection | No exception occurs. | |
Filter capacitor | Check whether there is electrolyte leakage, discoloration, cracks, and chassis expansion. | Visual inspection | No exception occurs. | |
Check whether the safety valves are released. | Determine the service life based on the maintenance information, or measure them through electrostatic capacity. | No exception occurs. | ||
Check whether the electrostatic capacity is measured as required. | Use instruments to measure the capacity. | Electrostatic capacity ≥ initial value × 0.85 | ||
Resistor | Check whether there is displacement caused due to overheat. | Olfactory and visual inspection | No exception occurs. | |
Check whether the resistors are disconnected. | Visual inspection, or remove one end of the connection cable and use a multimeter for measurement. | Resistance range: ±10% (of the standard resistance) | ||
Transformer and reactor | Check whether there is unusual vibration sounds or smells. | Auditory, olfactory, and visual inspection | No exception occurs. | |
Electromagnetic contactor and relay | Check whether there are vibration sounds in the workshop. | Auditory inspection | No exception occurs. | |
Check whether the contacts are in good contact. | Visual inspection | No exception occurs. | ||
Control circuit | Control PCB, connector | Check whether the screws and connectors loose. | Screw them up. | No exception occurs. |
Check whether there is unusual smell or discoloration. | Olfactory and visual inspection | No exception occurs. | ||
Check whether there are cracks, damage, deformation, or rust. | Visual inspection | No exception occurs. | ||
Check whether there is electrolyte leakage or deformation. | Visual inspection, and determine the service life based on the maintenance information. | No exception occurs. | ||
Cooling system | Cooling fan | Check whether there are unusual sounds or vibration. | Auditory and visual inspection, and turn the fan blades with your hand. | The rotation is smooth. |
Check whether the bolts loose. | Screw them up. | No exception occurs. | ||
Check whether there is discoloration caused due to overheat. | Visual inspection, and determine the service life based on the maintenance information. | No exception occurs. | ||
Ventilation duct | Check whether there are foreign matters blocking or attached to the cooling fan, air inlets, or air outlets. | Visual inspection | No exception occurs. | |
For more details about maintenance, contact the local INVT office, or visit our website www.invt.com, and choose Support > Service.