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- After repairing a large number of frequency converters, we found that many people encounter numerous issues when using them; let’s discuss these issues together here! A) Selection of inverter brand: Don’t focus only on price; some inverters are cheap, but their quality and performance are extremely poor! It uses shoddy materials, has a short lifespan, few spare parts, and is difficult to repair; if the entire circuit board needs to be replaced, the repair costs will be exorbitant ； Some companies can offer warranty services, but your drive may need to be sent to a city thousands of miles away, and it could take a month or two to get it repaired; therefore, when purchasing a drive, check whether there are any repair services available in the vicinity ； Some frequency converters, despite being from well-known brands, are quite delicate and require a favorable operating environment to perform well ； Some inverters are equipped with components that are quite \"exclusive and specialized,\" making them difficult to obtain at high prices; as a result, the repair costs are also high ； Another problem with inverters of poor performance is that once they burn out, the damage is quite severe, leaving little value for repair ； Inverters have a relatively high failure rate; therefore, when purchasing one, it is important to consider whether it is easy to repair, whether the inverter modules are standard and readily available ； If a certain model of frequency converter is used in large quantities, it’s best to purchase one or two extra units as spares ； If your frequency converter is used for simple speed control, choose the cost-effective series that is relatively inexpensive. If the motor load is heavy and sudden stops occur frequently, select a frequency converter with a higher capacity or better performance! B) —— The inverter should not be installed on equipment that experiences vibrations (such as injection molding machines, punching machines, washing machines), as this can cause the connection screws in the inverter’s main circuit to loosen. Many inverters get damaged for this reason! C) —— Wiring issue: It is advisable to connect an air switch to the input side of the inverter; the current rating of this switch should not be too high, so as to prevent severe damage to the inverter in the event of a short circuit The “N” terminal must not be grounded! Especially electricians of the older generation are most vulnerable to this! The control cable should not be too long, as this makes the control board susceptible to electromagnetic interference and causes malfunction! It can also cause damage to the control board! For lengths over 2 meters, it’s best to use shielded cable! Do not install contactors with high current and frequent operation next to the frequency converter! Because it causes significant interference to the inverter, often leading to incorrect operations of the inverter (with various fault messages appearing)! Some people, seeking convenience, keep the start control wire connected (such as Mitsubishi’s STF-SD), causing the motor to start as soon as power is supplied to the inverter. As a result, the inverter is prone to damaging the charging resistor due to the excessive current flowing through it! The ground wire must be properly connected to ground; otherwise, if the motor leaks electricity severely, the charged ground wire can also damage the inverter. D) —— For inverters that often need to be stopped abruptly, it is best not to rely on the inverter’s built-in braking system; instead, brake resistors should be used or mechanical brakes employed. Otherwise, the inverter will frequently be subjected to the back EMF from the motor, which will increase its failure rate! E) --- If the inverter operates at low speed frequently (