1. Q: what technical certificates FRECON has for frequency inverter?A: All of FRECON inverters passed the CE certification.2. Q: Which major cities in China have established service center of FRECON?   A: FRECON has logistics centers in the five major regions including East China (Wuxi), South China (Shenzhen), North China (Beijing), Southwestern (Chongqing), and Northeast (Shenyang). There are 13 offices in the country and has been established the nationwide logistics system and service network.3. Q: Which countries in overseas have established service center of FRECON?    A: The main countries including Pakistan, Afghanistan, Iran, Russia, India, Vietnam, Thailand, Morocco, South Africa, Turkey and so on.4. Q: How long is the supply cycle of FRECON’s frequency inverter?A:  Its one week generally. Different models and quantities, the supply cycle is different. Its according the business contract.5. Q: What about the overseas warranty policy of FRECON?   A: From ex-factory date to 24 months warranty service for quality problems.  6. Q: How to provide after-sales service for overseas drives of FRECON?A: The drives sold overseas are provided with after-sales service by local Distributors of FRECON. If the drives are within scope of warranty, provide free spare parts replacement, If the drives are above scope of warranty, provide paid spare parts replacement.7. Q: What information we need to provide after sale service?A: It needs to provide claim report, including company name, inverter model, inverter serial number, fault description, fault photo, contact information, etc.8. Q: How about the repair cycle of FRECON inverter in China?A: After receipt of the goods, within 2 days can complete unpacking, registration, quotation (the type of over warranty to charge fees), Repairing, testing, packaging, delivery and so on within 2 days.

1. Q: what is frequency inverter?A device that can convert the fixed voltage and fixed frequency to adjustable voltage and adjustable frequency.2. Q: what are the main circuits of the inverter?A: The rectifier part, the filter brake part, the inverter part.3. Q: How much does the FRECON inverter improve the motor power factor?A: Above 95%.4. Q: what is the protection level of FRECON inverter?A: ST200 model is IP55, all other models are IP20.5. Q: FR200 series inverter use the external potentiometer to adjust the speed, how to choose the potentiometer resistance?A: Generally, choose the potentiometer that the resistor value is 4.7k-10k ohm.6. Q: what is the role of the inverter buffer circuit?A: limit the charging current of the bus capacitance, and reduce the current impact on the rectifier bridge and the front-end switch.7. Q: What is the maximum baud rate of FRECON inverter RS485 communication?A: the maximum baud rate is 115200bps, and the default is 9600bps.8. Q: Inverter’s AC220V input voltage can connect to AC380V input or not ?A: No, there is danger of bombing.9. Q: When inverter reset the factory value, all the parameters are restored?A: Motor parameters (F08 group), fault records (U01 group), cumulative power-on time (U00.26) and cumulative running time (U00.27) are not restored.10. Q: How to check the bus voltage and output current after running?A: Through the keypad shift button to check it.11. Q: When inverter is constant pressure water supplied and is connected to the resistance type pressure gauge, is it needed to connect to resistor ?A: Need to connect a resistor that the resistance value is the same as pressure gauge (about 400Ω), in case of damage to the inverter 10v power and pressure gauge, pressure gauge working voltage is less than 6v, connect a resistor to divide voltage). 12. Q: what are the characteristics of automatic torque boost?A: We can improve the automatic torque to get bigger starting torque, but sometimes it is unstable, can change to manual torque (F09.01), setting this parameter correctly is good for motor locking.13. Q: what are the characteristics of the differential compensation gain application?A: when the load of the motor is increased, increase a bit of output frequency appropriately, so that the motor speed can be basically stable.14. Q: what is the flux brake?A: The inverter increases the stator flux by increasing the stator voltage, thus increasing the braking torque of the motor to realize quick braking. At the same time increase the stator flux of the motor, can make more stator excitation loss in the braking process,so that to reduce the energy feedback.15. Q: what is DC braking?A: The inverter gives the motor DC power, to produce fixed magnetic field, the motor cuts the magnetic field to generate electricity, and the kinetic energy is consumed in the form of heat energy on the rotor, to make the motor stop quickly.16. Q: What is dynamic braking?    A: The dynamic braking is a kind of braking mode, It transforms the generating capacity of the deceleration process into the heat energy of the braking resistor to achieve fast deceleration.17. Q: What’s the distance between the inverter and the motor ?A: Within 20 meters is short distance, 20 to 100 meters is medium distance, and over 100 meters is long distance.18. Q: What to do if the distance of frequency inverter and the motor is too long?A :(1) Choose larger power inverter;(2) Add output reactor, can effectively suppress the instantaneous high voltage generated by the IGBT switching, and reduce the bad effect by this voltage to cable insulation and motor.19. Q: what are the debugging steps of the inverter system?A :(1) Pre-power inspection;(2) Power-on inspection and parameter setting;(3) Motor no-load debugging;(4) Load debugging.20. Q: When PV series inverter is connected to the remote control system(RCS),what are the requirements for GPRS card?A: Control board hardware version need to be above V200, software version need to be above V1.22521. Q: What is the principle of energy saving of frequency inverter?A: Frequency inverter achieve energy saving through light load and voltage decreased, and the inverter output voltage increase when output frequency increase, it means that when the operation frequency is less than power frequency, it is saving energy (Take example: One fan just run 45 hz frequency can reach the required air volume, energy calculation formula compared to power frequency 50Hz is: 45^3/50^3*100%=72.9%, means it has 27.1% energy saving by using frequency inverter).22. Q:Does GPRS card support 4G communication?A: Yes, it supports the following network standard signal: LTE FDD: B1/B3/B5/B7/B8/B20LTE TDD: B38/B40/B41WCDMA: B1/B5/B8GSM: B3/B8。23. Q: If not remove capacitance, how to connect solar inverters with single phase motor?A:The PV100 is connected to the single-phase motor with the output terminal V and W, Power ≦ 0.75KW, PV200 is the same as PV100. Power ≧1.5KW, PV200 is connected to the single-phase motor with the output terminal U and W, and then setting F08.00 =3.24. Q: what are the control modes of the inverter?A：V/F sine pulse width modulation mode, open-loop vector control mode, closed-loop vector control mode25. Q: Why is the voltage of the inverter changes in proportional to the frequency?    A：When frequency conversion, the magnetic circuit of motor varies in a wide range with the operating frequency, it is very easy to make the magnetic circuit of the motor get saturated severely, which leads to a severe waveform distortion of the excitation current, to bring a peak current with high value. So frequency and voltage should varies proportionately, means control the output voltage of inverter when changing frequency, to make magnetic circuit of motor keep certain, avoid weak magnetic or magnetic saturation.26. Q: What is the difference between closed-loop control and open-loop control?A: Set the speed detector (Encoder) for the motor device used to feedback the actual speed to control device, it is the "closed-loop control", the one no needs sensor operation is called "open-loop control".27. Q: FR200-4T-045G/055PB-H diode gear measured R/S phase and  "+" as open state，Is it possible to judge the silicon control damage? A: No, FR200 series ≥ 37KW, the diode measured R/S phase and "+" as open state, it’s normal phenomenon.28. Q: how much energy consumption of the inverter is ?     A: The energy consumption of inverter is 3%-4%.29. Q:What are the main advantages of variable frequency start up?     A: (1) energy saving; (2) speed control, increasing production efficiency, and improving quality; (3) with soft start function, protecting the motor. 30. Q: How does the torque of the motor change when V and F are changed proportionately?     A: The voltage is reduced proportionately when the frequency drops. Since AC impedance becomes small and DC resistance doesn’t change, it will cause the torque produced at low speed will be reduced. Therefore, when V/f is given at low frequency, The torque boost is usually used to obtain a certain starting torque.31. Q: What is PID control?     A: In actual projects, the regulator control law of most widely used is proportional, integral, differential control, short for PID control. The parameter setting of the PID controller is the core content of the control system design. It is based on the characteristics of the controlled process to determine the value of proportionality coefficient, integration time and differential time of the PID controller.32. Q: How to deal with when there is a deviation in actual speed and given speed?     A: Usually in open loop control, even if the inverter outputs the given frequency, When the motor is running on load, the speed of the motor changes within the range of the rated slip (1%~5%). For the requirements of higher speed accuracy, even if the load changes, it also requires operation near a given speed, can use FR300 series for closed-loop control.33. Q: Can speed accuracy be improved by the feedback of PG card if using a motor with an encoder?     A: The inverter with PG feedback function can improve speed accuracy.34. Q: What is the meaning of the over-current stall function?     A: If the given acceleration and deceleration time is too short, the  change of the inverter output frequency is well over the change of speed (electric angle frequency). The inverter will be tripped over and stop because of over-current. This is called lose speed. In order to prevent the lose speed to keep running, the acceleration and deceleration rate should be slowed down when the acceleration and deceleration current is too large, so as to achieve over-current lose speed protection.35. Q: What is the frequency resolution ? What does it mean?A: For digital controlled inverters, even if the frequency command is an analog signal, the output frequency is also graded given. This minimum unit of gradation is called frequency resolution. The frequency resolution is usually valued at 0.01~0.5Hz, for example, the resolution is 0.5Hz, so the top of the 30Hz is changed to 30.5, 31 Hz, and the motor action is also a graded following.36. Q: Can FRECON’s inverter be used on the 60HZ power supply?A: Yes, the frequency range of inverter support is 50/60HZ, and the fluctuation range is ± 5%.37. Q: AC servo motor can be controlled by frequency inverter?A: Yes, but it can’t achieve the control accuracy of the servo controller.38. Q: what will happen if the input over-voltage ?A: If the input over-voltage, the inverter will report the overvoltage protection fault, even damage the internal circuit.39. Q: How does the inverter prevent thunder?A: Thunder strikes are divided into direct thunder and inductive thunder. The direct thunder strikes lightning directly on the drives, it causes the greatest damage; the inductive thunder is the inducted high pressure of electromagnetic wave produced by the lightning on the conductor, causing overvoltage of the electrical appliances connected to the conductors to damage. On the grid, the multi-stage arrester has been installed. However, the residual voltage of pre stage lightning or the lightning induced voltage near the inverter will still damage the inverter. Solution: install the line arrester in the inverter control cabinet. The line arresters usually use the power power supply lightning protection module, slideway installation, and parallel grounding. 40. Q: What causes the problem that the inverter stops and report over current fault when some high power motors start. How to solve it?A: when the large motor starts to run, it will pull down the voltage of the power grid, however the other load will cause too much current to report over-current when output frequency don’t change, so it stops running. The solution: increasing the capacity of  grid transformer.41. Q: is there any limitation when installing inverter?A: the inverter can be installed on the wall or a cabinet. In order to optimize the heat dissipation of the inverter, please install vertically.42. Q: what are the requirements for installation and use of inverter?A: the running temperature is between -10℃ and ~+40℃.If the temperature is between +40℃ and ~+50℃,it requires use higher power product. The relative humidity of the air need be lower than 95%, without condensation. When inverter installed at altitudes below 1000m, it can run at rated power. When inverter installed at altitudes below 1000m, it can run at rated power. When the altitude above 1000m, it requires downgrade by reduction of 1% per 100m in proportion to use. Keeping away from the application of electromagnetic radiation. It can use in the application for no oil mist, corrosive flammable gas. No radioactive material, metal dust, dust, oil, water and other foreign matter will not enter the place inside the inverter.43. Q: what are the requirements for the installation of the inverter for heat dissipation?A: According to the requirements of the operating temperature of the inverter below 40℃, it is recommended to install the radiator (air conditioner or fan) to achieve good heat dissipation effect. 44. Q: why is there a leakage current problem?A: When the inverter stops running, the leakage current is generally small. When the inverter is running, because of the high speed switching of the power module of the inverter, the higher harmonics exist in the output current. And because there is inductance between cable and ground, so producing the large leakage current. (can up to 10 times of inverter stops running).45. Q: How long is the electrolytic capacitor’s life expectancy？A: Electrolytic capacitors can normally be used for 40,000 hours.46. Q: What is the relationship between rated output voltage and DC bus voltage of inverter?A: Rated output voltage= Bus voltage/1.414.  

1. Q: Does FRECON has inverter of AC 220V input to 380V output?A: Yes, the SY380 series products, it’s single phase AC220V input, three phase AC380V output. 2. Q: How to choose the modle of  inverter?A: The rated output current of general inverter ≥ rated current of the motor, and the selection of input voltage should be considered voltage level.3. Q: What’s the power of Frecon inverters have built-in braking unit?A: All of FR100 series have built-in braking unit, FR200 series and FR300 series the power of 30kW and below have built-in braking units, the power of 37kW~75kW can choose if need built-in unit. The power of 90kW and above without built-in unit.4. Q: What is the output frequency range of the inverter?A: The frequency setting range of inverter can reach 0-600Hz. For the high output frequency requirements applications, We can provide FR200S series with output frequency up to 2000Hz.5. Q: Precautions for installation of inverterA: only professionals through training and qualified can do the installation operation, and please follow the instructions in "safety precautions". Before the installation operation, we must ensure that power supply of inverter has been disconnected. If inverter has been powered on, after power off, we must confirm POWER light has been putted out, it is suggested that the user directly use the multimeter to check the DC bus voltage is less than 36V.6. Q:  what components do we need to realize automatic AC/DC switching on PV series inverter? A: (1) a contactor.  (2) 2pcs prevent reverse diode 

1. Q: How to set maximum frequency of FRECON VFD?A：Set F01.08 as required value (50Hz).2. Q: How to change FRECON VFD parameters by controlling keyboard?A: Setting F00.02=0, F00.06 = 03. Q: How to control VFD start/stop by terminal?A: Choose switch with normal open point, Connect one side of normal open point to DI1, and the other side to COM; Setting F02.00=1, F04.00=14. Q:How to set parameters when the output frequency of PV series fluctuates and water volume is unstable.A: Setting H00.02=3 (fast MPPT) can solve the problem effectively.5. Q: How to connect and set parameters when PV100 series connect single phase motor without remove capacitance?A: (1) motor lines connect V and W terminals; (2) set parameter F08.00=3 

1 Q: How to solve the problem when the VFD and PLC can't communicate through 485 communication.  A: (1)Check if communication cable is connected correctly.  (2) Check if VFD is consistent with the PLC communication baud rate (F100) and the communication format (F101); If there are multiple VFDs, check if the address of the station is conflicting, the first and last terminal resistors need to be added.    (3) Check if PLC program is correct.2 Q: how to slove the problem when the VFD’s frequency is given by the AI voltage signal, but frequency doesn’t rise.A: (1) Check if AI dial switch is dialed to the voltage side (V)  (2) Check if maximum input voltage is up to 10V.3 Q: How to solve motor stop fast, and report over-current, over-voltage fault? A: (1) Enlarge deceleration time (F03.01). (2) The load inertia is large, adding brake resistance.  (3) Setting F09.11=0, F11.06 decrease (630V).4 Q: How to solve the problem of VFD runs, but motor don’t run?A:  (1) Check if output of three-phase U/V/W has voltage output, If not, Power off to check if main circuit of rectifier and VFD is normal. If there has voltage output, check if motor is blocked (can remove the load).  (2) Check if given frequency of VFD is less than starting frequency.5 Q: How to solve the problem of VFD and PLC can communicate normally, but frequency can’t be given?A: Setting F01.01=36 Q：Q: how to connect power line of PV200 series solar pump inverterA: (1) the power of PV200-4T series ≦30kW, and power of PV200-2T series ≦15kW can directly connected to +/- terminal. (2) the powerof PV200-4T series≧ 37kW, and power of PV200-2T series ≧18.5 kW , positive connection R/S/T terminal, negative connection - terminal.7 Q: When installing a circuit breaker with leakage protection. How to deal with if circuit breaker always tripping during operation?A: (1) Connect inverter to ground wire of motor and ensure reliable grounding; (2) Reduce carrier frequency of inverter; (3) Disconnect RFI short wiring.8 Q: How to check when keyboard display darkens and running frequency down.A: (1) check is keyboard is in good contact with VFD’s control board; (2) set parameter F01.01=0, and check by digit-given whether the running frequency will be reduced.9 Q: How to solve the problem after inverter power on, but can’t enter into parameter, and display "-----"?A: Its because the customer has set user password. (1) Customer enters the correct password; (2) Feedback to FRECON distributor to solve.10 Q: What will cause the invalid of DI terminal function.A: Possible causes for invalid DI terminal function: (1) terminal 24V and PLC short connection have been removed. (2) the voltage of terminal 24V is abnormal. (3) terminal damage. (4)  terminal wiring error. (5) The parameter setting is incorrect.11 Q: Reasons for no display on the keyboard.A: (1) The keyboard line don’t connect well, or keyboard is burnt out ; (2) Control board is damaged; (3) The power supply of driving power board is damaged; (4) Rectifier bridge is damaged.12 Q: How to check the main circuit?A: Check with the digital multimeter with diode gear, the negative probe (black probe) point at inverter "+" pole, the positive probe (red probe) point at the inverter input terminal R, S, T and output terminal U, V, W in turn ; Measured rectifier bridge pressure drop of R, S, T terminal is about 0.3-0.6V, and module pressure drop of terminal U, V, W between 0.3-0.6V and three phases are balanced. Then, in reverse, the positive probe (red probe) point at the inverter  "-" pole. if the measured result is the same, its meaning that the pressure drop of main circuit is normal ( for the power of FR200-4T series ≧37kW , Its also normal to measure the state between R, S, and ” +” is an open circuit )13 Q: What is the reasons of inverter report ERR08 when start running ?A: if the inverter do not connect with motor, the possible cause of reporting ERR08 is: (1) the control board is not good; (2) the drive board or IGBT is damaged.14 Q: Why the inverter can’t stop after pressing stop key and also don’t report fault?A: If the voltage is not high, the possible causes of the fault are:(1) the key of inverter is not good. (2) when stop key is pressed, inverter decelerate too fast, the inertia of load is very large, and there is no brake device. (3) the main control board is damaged.15 Q: What are the precautions for peripheral interference for the inverter?A: inverter is a harmonic source, which is easy to interfere with control device. So the inverter must be connected with ground correctly, and the correctly connect will reduce the interference of the device by 60%16 Q: How to solve the problem FR series motor self learning fault ERR17?A: (1) Check if the motor is connected before self-learning, make sure that the motor is connected properly with the inverter. (2) check if motor capacity matches with inverter capacity, for example, if the inverter capacity is too small, it is necessary to replace inverter that matches the motor capacity. (3)  Check if rated parameters of motor are set correctly, and ensure that parameters are set correctly before learning.17 Q:How to check the problem of FR series report overload of motor ERR11 when runs?A: (1) check whether the rate parameter setting of the motor is correct,if not, please reset it. (2) check whether the setting of motor protection parameters is correct. (F11.10, F11.17, F11.18, F11.19), set the protection parameters correctly. (3) check whether the motor is blocked or not. 18 Q:How to solve the problem of FR series overload of inverter ERR12 when runs?A: (1) check whether the motor is blocked or not? (2) check whether the inverter module setting is correct ( if can match with type of load , if not,resetting the type) (3) check whether the keyboard display current is the same with actual value, if its the same, suggest to replace the larger power inverter. 19 Q: How to solve the problem of FR series report accelerating overcurrent ERR01 when runs?A: (1) check whether to restart the rotating motor. If it is, can wait until the motor stops and start or set the speed tracking start. (2) check whether the acceleration time of the inverter is too short. increasing the acceleration time If user allows. And If the customer's technology allows, suggest to replace to higher power inverter. (3) check whether the load is abrupt in the acceleration of the inverter. If so, increasing the protection value or increasing the acceleration time. (4) check whether the output line is too long, generally more than 100m, need to install output reactor or filter.20 Q: How to check the problem of FR series report deceleration over-current ERR02 when runs?A: (1) check whether the acceleration time of the inverter is too short. increasing the acceleration time If user allows. And If the customer's technology allows, suggest to replace to higher power inverter. (2) check whether the load is abrupt in the acceleration of the inverter. If so, increasing the protection value or increasing the acceleration time. (3) check whether the output line is too long, generally more than 100m, need to install output reactor or filter. (4) Check if there is braking resistor. If If you need fast deceleration, suggest to increase braking resistor.21 Q: How to check the problem of FR series report constant speed over-current ERR03 when runs?A: (1)Check whether the load is abrupt in the acceleration of the inverter. If so, remove the sudden load. (2) check whether the output line is too long, generally more than 100m, need to install output reactor or filter. (3) suggest to replace high power inverter.22 Q: How to solve the problem of FR series report acceleration over-voltage ERR04 when runs?A: (1) check if the input voltage is higher, adjust voltage to normal range, so that DC bus voltage isn’t higher than overvoltage value. (2) Check if the acceleration time is too short and properly increase the acceleration time when conditions permit. (3) check if there is any external force to drive the motor in the acceleration process. If so, suggest to remove the force or install the brake device.23 Q: How to solve the problem of FR series report deceleration over-voltage when runs?A: (1) check if the input voltage is higher, adjust voltage to normal range, so that DC bus voltage isn’t higher than overvoltage value.(2) Check if the acceleration time is too short and properly increase the acceleration time when conditions permit.(3) Check if the load is rotating with too much inertia, or  there is any external force to drive the motor in the acceleration process,  If there is external force, remove the force or change to free parking. (4) If can’t meet the condition of (3), suggest to install the brake device.24 Q: How to check the problem of FR series report constant speed over-voltage ERR06 when runs?A: (1) check if the input voltage is higher, adjust voltage to normal range, so that DC bus voltage isn’t higher than overvoltage value. (2) check whether the load is abrupt in the running of the inverter. If so, remove the sudden load.25 Q:How to check the problem of FR series report bus under-voltage ERR07 when runs ?A: (1) check if the input voltage is lower, adjust the voltage to normal range. (2) check if the rectifier circuit of the drive board is normal. (3) change the control board to check again.26 Q: How to check the problem of  FR series report Input Open-phase ERR09 when runs?A: (1) Check if the three-phase input terminal screws are tight and tighten the screws. (2) check if the three-phase input voltage is normal balance, adjust the voltage to normal range. (3) check if the main circuit of the drive board is normal.27 Q: How to check the problem of  FR series report output Open-phase ERR010 when runs?A: (1) Check if the three-phase output terminal screws are tight and tighten the screws. (2) Remove the motor line and check if the three phase output voltage is normal (3) Check if the main circuit of the drive board is normal.28 Q: How to check the problem of  FR series report Memory Failure ERR015 when runs?A: (1) setting F11.11=00020 (2) change control board to check again29 Q: How to check the problem of FR series report Disconnection Fault of temperature sensor ERR024 when runs?A: (1) check if the display temperature of U00.23 is normal.(2) Check if cable connection between control board and drive board is normal. (3) change temperature detection element.30 Q: How to check the problem of FR series report Soft-start relay unclosed ERR027 when runs?A: (1) Check if input voltage is lower, adjust the voltage to the normal range. (2) Check if rectifier circuit of drive board is normal. (3) change control board to check again. 31 Q: How to check the problem of FR series report Hardware detect Over-current ERR029 when runs?A: (1) Check if the motor is short-circuited to ground and short-circuit between phases to eliminate faults.(2) Check if the inverter acceleration/deceleration time is too short and extend the acceleration/deceleration time. (3) Check if the load is abrupt during the acceleration, If yes, cancel sudden load.(4) Check if the input voltage is lower. (5) Check if start motor that it hasn’t completely stopped (6) Check if the motor cable is too longer.32 Q: How to check the problem of FR series report Hardware detect over-voltage ERR030 when runs?A: (1) Check if the input voltage is higher. (2) Check if the deceleration time is too shorter. (3) check if the load inertia is too large. If so, suggest to install the brake resistor.33 Q: How to solve the problem when PV series connect with single phase motor, and power of photovoltaic panels is enough, but the running frequency can’t be improved?A: (1) exchange two-phase motor line (2) Increase solar panels to increase voltage. (3) Set F01.08 to a larger value.34 Q: What is the reason for PV series report A33 when running?A: A33 means Pre-warning of Weak light, it is caused by insufficient voltage of photovoltaic panel. The weak voltage of AC110V PV series inverter is DC80V. The weak voltage of AC220V PV series inverter is DC120V. The  weak voltage of AC380V PV series inverter is DC250V.