1 变频器无输出电压 The frequency converter has no output voltage 原因为： The reason is: (1)主回路不通 重点检查主回路通道中所有开关、断路器、接触器及电力电子器件是否完好，导线接头有无接触不良或松脱。 (1) the primary loop Focusing on all the primary loop channel switch, circuit breaker, contactor and power electronic devices are in good condition, wire connector have poor contact or loose. (2)控制回路接线错误，变频器未正常起动以说明书为依据，认真核对控制回路接线，找出错误处并加以纠正。 (2) the control circuit connection error, the frequency converter is not normally starting with the instruction manual, carefully check the control circuit connection, find the wrong place and correct it. 2 电动机不能升速 The motor cannot be raised fast 主要原因为： The main reasons are: (1)交流电源或变频器输出缺相 电源缺相使变频器输出电压降低，变频器输出缺相造成三相电压不对称而产生负序转矩，都使电动机电磁转矩变小，不能驱动负载加速，应检查熔丝有无烧断，导线接头有无松脱断路。 (1) ac power or the inverter output lacks power lacks make the inverter output voltage is reduced, the inverter output phase caused by asymmetric three-phase voltage and negative sequence torque, made motor electromagnetic torque is smaller, can't drive load acceleration, should look for burn out fuse, wire connector loose open circuit. (2)频率或电流设定值偏小 频率设定在低值点上使频率受到限制无法升高而不能加速。电流值设定偏小，则产生最大转矩的能力被限制，使电动机剩余转矩过小而不能加速。因此，应检查频率和电流设定值是否适当。若电流设定值已达变频器的最大值，这说明变频器容量偏小，应换较大容量变频器。 (2) the frequency or the set of the current setting is set at a low point where the frequency is restricted and cannot be accelerated. The capacity of the maximum torque is limited by the small amount of the current setting, so that the residual torque of the motor is too small to accelerate. Therefore, the frequency and current Settings should be checked for proper values. If the current set value has reached the maximum of the frequency converter, this means that the frequency converter capacity is small, and the frequency converter should be changed. (3)调速电位器接触不良或相关元件损坏频率给定值不能升高。 (3) the frequency of failure of the frequency of contact or damage of the relative components of the regulator is not increased. 3 转速不稳定或不能平滑调节 Unstable or not smooth 这种故障一般是受外界条件变化的影响，无规律且多为短暂性，主要影响源为： (1)电源电压不稳定。 (2)负载有较大波动。(3)外界噪声干扰使设定频率起变化，可通过检测找到故障点和采取相应的解决措施。 This kind of failure is usually affected by the change of external conditions, irregular and mostly transient, the main effect is: (1) the power supply voltage is unstable. (2) the load has a large fluctuation. (3) noise disturbance causes the setting frequency to change, but the fault points and corresponding solutions can be detected by detection. 4 过电流故障 Over current fault 这是较常见的故障，可从电源负载，变频器振荡干扰等方面找原因。 This is a more common fault, which can be found from the source load, the frequency changer, and so on. (1)电源电压超限或缺相 电压超限而过高或过低，应按说明书规定的范围进行调整。无论电源缺相或变频器输出缺相，都导致电动机转矩减小而过流。 (1) if the power supply voltage exceeds the limit and the voltage limit is too high or too low, it should be adjusted according to the scope of the specification. The motor torque is decreased regardless of the power supply or the output of the converter. (2)负载过重或负载侧短路 重点检查机组无异声，振动和卡滞现象，是否因工艺条件或操作方法改变而造成超载。负载侧短路或接地．可用兆欧表进行检测。逆变器同一桥臂的两只晶体管同时导通也形成短路。 (2) under the heavy load or load or short-circuit Key inspection unit is sound, vibration and card lag phenomenon, whether the overload caused by process conditions or changes in operating method. Load side short circuit or ground. Can be detected by megabit. Two transistors on the same bridge arm of the inverter also short-circuit.