Videos on how to test the big transformer for LF inverter.

Videos on how to test the big transformer for LF inverter.
On 12v to 220v:
http://video.tudou.com/v/XMjQ2MDk3MzE3Mg==.html?spm=a2h3j.8428770.3416059.1
On 24v to 220v:
http://video.tudou.com/v/XMjQ2MDk3MzE3Ng==.html?spm=a2h3j.8428770.3416059.1
On 48v to 220v:
http://video.tudou.com/v/XMjQ2MDk3MzEyNA==.html?spm=a2h3j.8428770.3416059.1

Question on solar controller

Q: Could I connect your solar controller to 24v solar panel, and charge 12v battery?
A: No, if you connect to 24v solar panel, then you only can charge 24v battery. If you want to charge 12v battery, then you need connect to 12v solar panel.

What does it mean for different buzzer alarm situation on LF inverter?

What does it mean for different buzzer alarm situation on LF inverter?

1. Low voltage alarm: INV ON green light and red light will be on, with short alarm once every five seconds; there is an output, and the inverter does not turn off.
2. Low voltage shutdown: no light will be on with buzzer alarm, and there is no output.
3. High voltage alarm: INV ON green light and red light will be on, with short alarm once every one second, and there is an output; the alarm lasts about one minutes (57 times) then only INV ON green light will be on, still with buzzer alarm, and there is no output.
4. High voltage shutdown: after the inverter is turned on, the buzzer alarms, INV ON green light will be on for 10 seconds, then all lights will be off, and there is no put.
5. Temperature protection: INV ON green light and red light will be on, with 3 times of short alarm and later the buzzer alarms without output of the; then no light will be on, but the fan will be running; after the temperature drops, the fan stops running, and the inverter keeps alarming without output.
6. Overload protection: there are three levels of this situation: slight overload (the overload is no more 400w than the set load), INV ON green light and red light will be on without alarm, and the inverter is working without off; moderate overload (the overload is 400w-1000w more than the set load), INV ON green light and red light will be on with a short alarm once every one second, and there is an output; one minute after, the buzzer alarms without output, and no light will be on; heavy overload (the overload is about 1000w more than the set load), INV ON green light and red light will be on with a short alarm once every one second, and there is an output; 10 seconds after, the buzzer alarms without output, and no light will be on.
Note：If the LF inverter is not equipped with the function of automatic start after alarm and shut down, please switch off the inverter and restart it .  

What's the difference between HF(high frequency) inverter and LF(low frequency) inverter?

What's the difference between HF(high frequency) inverter and LF(low frequency) inverter?

What is the difference between (PI)modified sine wave inverter and (PSW)pure sine wave inverter?

What is the difference between (PI)modified sine wave inverter and (PSW)pure sine wave inverter?

Modified Sine Wave Inverter: If your equipment can accept some voltage fluctuation, consider a modified sine wave inverter. These inverters provide mobile power at a more affordable price and come in a full range of sizes. 

Pure Sine Wave Inverter: If you want to run your equipment exactly to the manufacturer's specifications, choose a true sine wave inverter. With true sine wave, motor loads start easier and run cooler. Some equipment only operate properly with true sine wave power—laser printers, variable speed motors and digital clocks. Waveform is an important consideration when choosing an inverter. sine wave inverters provide premium power that is identical to or even better than power supplied by your utility company. Modified sine wave inverters provide good performance at a great value.

Fault Analysis and Detection Methods on Defective Pure Sine Wave Inverter?

Fault Analysis and Detection Methods on Defective Pure Sine Wave Inverter?

The following six situations are normal:

1. turn on: when turn on the inverter, the buzzer will beep once, red led light on for a few second, then green light keeps on.

2. low input voltage alarm:  when the input voltage is lower than 11.0V±0.5V, the buzzer will beep twice, at this time, the green light keeps on like when turn it on, the output is normal, the inverer can work.

3. low input voltage protection: when the input voltage is lower than 10.5V±0.5V, the buzzer will beep three times, at this time, the inverter off AC output and the red light on.

4. over input voltage protection: when the input voltage is over than 15V±0.5V, the buzzer will beep four times, at this time, the inverter off AC output and the red light on.

5. temperature protection: when the temperature of the inverter is over 45℃±5℃, the cooling fan will run; when the temperature is over 80℃±5℃, the buzzer will beep five times. at this time, the inverter off AC output and the red light on, the fan will keep running.

6. over load protection: when the inverter is with load, the buzzer will keep beep for about 10times constantly, the green light is still on, when the beeps stop, the red light will be on, about after 8seconds the inverter will restart again. Sometimes both the red and green light on, low input voltage, but without alarm.

Need to open the inverter to check the inside circuit boars when has the following situations:

1. red light off, green light on, without output:

a. check the output socket to see if there has any loosing connections.

b. check the IC on the C1 board near the AC side to see if there has any IC is not tightly connected, check the 15V power supply on the C1 board to see if it is normal, if yes, then tru to replace the crystal on the C1 board.

2. green light off, red light on. If alarms, then need to check as the above situations; if not alarm, then need to check the followings:

a. check the mosfet on the DC side(RU4099 on 12v type, and 05CN10 on 24v type), and their corresponding diode(P6KE39A on 12v type, and P6KE75A on 24v type), and also check the 10 ohm resistor.

b. check the mosfet on the AC side(IRFP4232,G80N60 on 110v item, G40N60, G80N60 on 220v item), if they are burnt, then need to check their corresponding 2.2 ohm resistor and diode 1N4148, also the IC（IR2110 or IR2113）on the C1 board.

c. if there has short circuit when connected the battery but not turn on, then there has damage on the  mosfet on the DC side(RU4099 on 12v type, and 05CN10 on 24v type) and the diode (P6KE39A on 12v type, and P6KE75A on 24v type), if there has short circuit when connected the battery and turn on, then there has damage on the rectifier diode of the high voltage position.

3. no response on both the red and green light:

a. check if the switch cable is loosing or not, the slot line is tightly plugged or not.

b. check if the DC fuse is disconnected, if yes, then need to check the DC mosfet and the diode on the high voltage position(U8100E, RHRP8120,RHRP1560,RHRP29-06) to see if they are burnt or not.

c. check the two power supply(13V and 15V) on the small DC board are normal or not, whether there has any damaged component.

4. both green light and red light on(or green light on, red light flickers)

a. check of it is over load protection, if yes, then it will alarm as well, and the AC output voltage reduce, because of over load, at this time, need to test with small load. When run inductive load and with air compression type load)the surge maybe about 10-15times), turn on the inverter, the red light will flicker, after about 10seconds, if the output voltage is normal, also it works well when run other load, then the inverter is ok.

b. if the output voltage is normal, the inverter works, then the transistor(SS8050) or other related component broken, this will not affect the use of the inverter.

Fault Analysis and Detection Methods on Defective Modified Power Inverter?

Fault Analysis and Detection Methods on Defective Modified Power Inverter?

Defective modified power inverter have following situations:

One. Red led light, buzzer alarm

1. Undervoltage protection (low voltage protection) over-voltage protection: the operating range of 12V system is 11V-16V, and 24V system is 22V-30V. When the battery voltage is below or above this range, the inverter will not work properly.

2. Temperature protection: the inverter work for a period of time, the temperature of the whole inverter will slowly rise as the temperature rises, the fan of the inverter will first starts, when the temperature of the mosfet rise to 90 degrees, the inverter will be alarm to protect, temperature protection.

3. Overload protection: when the power of the appliance or surge power(any appliance with motor inside has surge power) over the overlaod range of the inverter, the red led will turn on, alarm to protect.

4. Thermistor off: if the thermistor is damaged, the inverter will be red light, and alarm to protect, so when this situation happens, need to use the multimeter and adjust it to DC200V position, and then test the DC input voltage to see if it is in the working range. Also, need to know what is the appliance and the watts of this appliance, with motor or not, what is the working time.

Two. Green light on, abnormal output voltage

AC output voltage, as to 220v item, only shows 140v, as to 110v item, only shows 70v, there are two situations:

1. only one AC fuse got burnt, the corresponding mosfet maybe also got burnt.

2. The waveform of the AC side drive maybe only shows half-waveform, due to the damaged component on the circuit board or the circuit breaker. If the voltage is abnormal, need to check if the AC fuse got burnt, adjust the multimeter to diode position, and then test the mosfet(the black pen touches the second leg, and the red pen touched the third leg), the normal reading is about 380, if the reading is very small or very large, then the mosfet is damaged; at this time, need to test the corresponding resistor, the right reading is 220 ohm.

Three. Green light on, normal voltage when no-load, very low voltage when load. There are two situations:

1. DC fuse maybe got burnt;

2. The PWM signal output shows abnormal on the controll board.

3. Testing method: open the inverter, adjust the multimeter to diode position and then test the DC fuse, if it shows 0, then it is good; if it shows 1, then it is bad, at this time, need to test the corresponding mosfet(the black pen touches the second leg, and the red pen touched the third leg), the normal reading is about 420, if the reading is very small or very large, then the mosfet is damaged; at this time, need to test the corresponding resistor, the right reading is 10 ohm.

Four. No response on the led light, no response when turn on the inverter.

Testing method: open the inverter, check inside to see of there has any loosing connections or any burnt parts; if not, then adjust the multimeter to diode position, and then test the switch to see if it works when it switches to “ON”; then test the 1st leg and the 20^th leg of the CPU on the big board to see it shows 5V.