AIMS PWRINV8KW12V 8000W Watt 12V 120VAC inverter 16000W surge 1 second 24000W

Description: 8000W AIMS PWRINV8KW12V POWER INVERTER WITH ABOVE AVERAGE SURGE ABILITY (compared to other modified square wave inverters. The AIMS LF pure sine units have 3x for 30 second surge which is way better, but also really expensive). My 6 month personal guarantee. See below. This is a big inverter that can power any 120VAC power tool even 20 Amp air compressors. It's great for wood shops that don't have power available. 4 group 27 marine batteries will be enough to make it deliver its full potential for short periods of time. THIS IS THE CLASSIC VERSION, NOT THE NEWER SMALLER VERSION THAT'S SELLING ON EBAY FOR $700. THIS UNIT IS BUILT MUCH HEAVIER AND HAS LOTS OF ALUMINUM COOLING AREA. The four outlets are all in a row on the new smaller version. I had a hard time finding the surge specifications for the newer more compact 8kW AIMS inverters, but one source I found said that the surge time is only 40mS. That's about long enough for a light bulb to warm up, not for motor starting. This inverter should have 1 second of 16,000W surge time. The surge time is load dependent (based on a capacitor charging up), so starting from no load the surge time is probably over 1.5 seconds. It'll probably do 24,000W for 1/2 a second as well. Eventually the short circuit protection will trip at around 300 Amps of output. Output is "modified sine wave" 3 step square wave output with fixed duty cycle at about .75 on time and .25 dead (0V output) time. That's good for running motor since motors like to have a sine wave, and having 25% dead time is somewhat close to that. Voltage regulation is done separately not by adjusting the dead time like cheaper inverters. When cheaper inverters have low input voltage and high load they decrease the dead time so the output comes close to being a square wave which makes motors run even less efficiently and produce more heat. This inverter has been somewhat modified. When I got it I discovered that the short circuit protection was missing. I saw that two glass diodes had been snipped from the control board. I don't know how they got that way. Was it that way from the factory? I got this inverter broken on eBay and I replaced all 48 of the DC-DC side MOSFETs. After a lengthy analysis I found that one snipped diode sends the short circuit signal to a circuit that immediately shuts off the output and keeps it off briefly and then reset itself. The other diode sends a shut down signal to the DC-DC input side of the inverter which has some delay. After a short condition remains for a bit over 1/2 a second the inverter will shut down because of the second diode. Each of these diodes has an N and a little arrow marked on the board beside it that I put there. Did they have problems with nuisance overload tripping and so they disabled the short circuit protection? The other thing I did is I disconnected a resistor (RX4) which enables a feature that briefly doubles the short circuit threshold to around 600 Amps during the leading edges of the square wave output. The normal threshold is around 300 Amps. 300 Amps is the maximum that the output MOSFETs can handle at 25C. They can handle 600 Amps briefly but any kind of inductive load on the output can cause that 600 Amps to continue to flow after the output has shut off and gone shorted and this will blow the lower output H bridge. Maybe this was added because of nuisance tripping of the short circuit protection. I don't know. I was only able to test it with two batteries up to about half of its rated capacity with a table saw and there was no problem with nuisance tripping. Maybe at full capacity the short circuit protection erroneously trips. If so you can take the top off and solder RX4 back in. There's writing on the circuit board and an arrow pointing to it. Most likely you won't need all 8000W of power and having working short circuit protection on such an expensive inverter is worth it. You can short the output terminal with two screw drivers touching together and it'll protect itself without damage, but with a longer piece of wire or other inductive load I still don't know if it would be protected even with my modification. It should be but I wouldn't test it! RX4 is a 1k shunt resistor that's controlled by an NPN transistor that's in parallel with another 1k shunt resistor. That makes up the bottom of a 20k and 1k voltage divider that goes to an OP amp that has a reference that's at about .1 Volt. That means that the input voltage will need to be around 2 Volts for it to trip. Based on the sense resistor sizes on the main circuit boards that comes out to around 300 Amps, or 600 Amps when the NPN transistor is turned on. I think it should be hooked up on the DC side like I have done in the picture. I'm not sure what the short red wires are for but it came with them and I assume they help distribute the current to the 3 different parallel circuit boards. I think they also make a 10000W inverter where all 8 (4 pairs) of DC input terminals are used internally. This one only uses 3 of the input terminals. The one pair that is skipped does draw load internally but I put the patch wires up to the end just in case someone decided to hook it up there so it would help distribute some current away and not over load the bus bar internally. Those two at the end are actually not used internally. The 3 other pairs are. It looks like it was exposed to rain at one point and some water did pool up on the edges of the circuit boards. I'm not sure if that's what caused the failure or not. But I cleaned all that out. 3 step square wave output (modified sine wave). Isolated output! (for hooking it safely to house power and not damaging the inverter if the output shorts to the input) Fan does not run continuously. Solid metal chassis. Mostly complete overload protection. 4 AC outlets Low input voltage automatic restart (at least during my test which had it under a moderate load) automatic recovery from brief short circuits. Repeated short circuits cause a fault shut down. Overload causes a fault shut down. I accept various types of payment, like payment through the mail, but it may take some time to clear. REVERSE POLARITY IS NOT PROTECTED. It will probably just blow the fuses but more damage could happen. Warranty details: This is my personal guarantee. If it breaks print a copy of your purchase or use the included invoice and then contact me to send it back for repair, replacement, or refund, my choice. The warranty is valid for 6 months after purchase or the mail delivery date if that has been recorded. You must pay for shipping when sending it to me. I pay return shipping as long as it is not an international shipment. The warranty only covers one full repair, replacement, or refund. After the first claim, the warranty is limited to either a repaired or replaced unit or an 80% refund of your original purchase price, not including the shipping. Again, my choice.The following things are not covered by the warranty: Physical damage to the chassis of the unit, damage caused by physical shock, damage caused by storing or operating the device outside of the normal allowed storing or operating temperatures, harm from excessively dirty environments, or condensing humidity, or damage caused by improper electrical connections, or power surges, or damage to any other device(s) connected to the unit. Expect to wait up to six weeks from sending it in for the warranty process to complete. Below is some general information about inverters. I plan to print it and include it with the inverter. What devices can be operated by an inverter? Sizing: Is the inverter big enough? Simple: Look on the back of the device by the regulatory certification markings to see how many watts the device uses. If it only lists Amps, then multiply Amps by 120 to calculate watts (or technically VA for motors and other inductive loads). Use an inverter that is rated for at least this many watts. Motors use 3 to 7 times as many Amps during start up, so an inverter with a suitable surge rating may be needed. Tube TVs have a power on surge too. Power supplies like those on computers often have an Amp rating that is much higher than they really use. Advanced: To put things in perspective, a standard 15 Amp circuit can handle a 90A surge current for 0.6 to 1.7 seconds and puts out 1800W or VA continuously, so a 2000W inverter will run anything, except things like motors which have start up surges. To calculate a motor's wattage, multiply it's current by 120, this gives you VA (or Volt Amps, which a measure of watts used by the motor and energy in watts stored in the magnetic field and then re-injected back in to the supply unused). Multiply VA by the power factor if that is listed. Now you have the actual watts that the motor uses. A good 3 step square wave inverter can usually handle a bad power factor (higher VA than watts), but a generator or pure sine wave inverter often cannot, so use VA instead of Watts where appropriate. Watts are equal to the motor's mechanical power output and inefficiency (heat generated). A general purpose induction motor is made to only run at one speed, and puts full torque during start up but draws around 6 times the normal full load current to do so. They make a single click noise when spinning down just before stopping and usually have a capacitor mounted on the side. Some examples of their uses are: air compressors, machine tools, and farm equipment. Specialized induction motors which are found in many refrigeration compressors, vacuum cleaners, fans, and sump pumps do not draw as much start up current because full torque isn't needed. Lastly there are universal motors with brushes which are found in kitchen appliances, power tools and many other intermittently used tools. They put out torque which is proportional to the current drawn. They can put out very high power when overloaded. They draw a large current surge during start up, but start up very quickly. They don't need extra current during start up, but will use it. For a general purpose induction motor, an inverter with a surge capacity of 6 times the motor wattage may be needed, and that surge time may need to be close to one second. For example, an air compressor with a full air tank is one of the most demanding tasks for an inverter. An 1800VA 15A 1.5HP air compressor would need an inverter with 12000W surge capacity for 0.5 to 1 seconds. A battery bank with over 2000 cranking amps is probably needed for a 12 Volt system. The soft start feature of an inverter wouldn't do any good for this, unless the tank were empty. For smaller specialized induction motors, most inverters have enough surge capacity to start them. Else, the soft start feature will allow it to start. For brushed universal motors, the surge power and soft start is plenty to get it going so a high surge capacity inverter isn't needed. Keep in mind whether the surge and soft start features of an inverter happen only when when the inverter is turned on, after an overload reset, or kick in dynamically while it is operating. Manufacturers usually don't give such details about their inverter's features. Some inverters put out the surge power for such a short time that it is useless. Others do surge only at turn on, and then just do soft start while operating, so the inverter may have to be turned off and on each time the device is used. Good inverters will have surge power available at any time while operating. If soft start is needed to start a device while the inverter is operating, then voltage will be briefly reduced to any other devices plugged in to it. Refrigerator compressors stall very quickly, and TVs and other electronics may have to be turned back on. Power source and batteries to use: Marine or deep cycle batteries should be used to power an inverter. Don't use car or engine starting batteries. They aren't designed to be discharged below 90%. They will be ruined before 50 full discharges. A marine battery will typically last 250 full discharges or 1000 50% discharges. Deep cycle are best if normal use requires discharging below 50% charge. Lead acid batteries become inefficient when discharged quickly. A 100 AH over 20 hour battery that's powering a 2000W inverter that's using all 200 Amps should operate for 30 minutes, but due to the high discharge rate loss it'll only run for only 7 to 15 minutes. Parallel batteries together and discharge them all at once, don't discharge them one at a time in high load applications. Use fuses where appropriate. If an idling car is providing power, don't expect the car's alternator to be able to keep the battery charged if the average load is over 400 to 800W. What devices can be used on a "modified sine wave"? The output of this type of inverter is a 3 step square wave, or "modified sine/square wave" instead of a pure sine wave. Modified square wave inverters are usually a bit more efficient than pure sine because of the lack of a final switching stage and coil. They also tend to tolerate poor power factors without shutting down (a 1000W inverter may handle 1500VA). The output voltage of a 3 step square wave inverter alternates quickly between about +145V, 0V, and -145V rather than a smooth transition. This is better than old inverters and many computer UPS units that put out 2 step square waves. A 3 step square wave can operate almost all devices that normally operate on normal sine wave AC power, but there are a some exceptions. All devices are designed to handle a sharp voltage spike when first plugged in or turned on, but the repeated spikes from the alternating square wave are what make certain devices unusable. The following devices should not be used on this kind of output: Any device which uses a capacitor to limit current. These include: Some fluorescent lights and other special high brightness lighting with a capacitor ballast instead of an inductor. Battery chargers which having a warning saying that high voltage is present at the terminals. Small battery chargers such as plug in rechargeable flash lights, battery charges for razors and tooth brushes, and battery chargers for some power tool batteries. If the device becomes excessively hot when used, then disconnect it. These are the most frequently damaged devices. If the battery charger gets slightly warm or makes a faint hum when it is not charging a battery then it probably uses a transformer, and it is safe to use. Some induction motors will start oscillating, especially at light load. They start drawing high current spikes several times or more per second. This usually makes lights that are connected to the circuit flicker and the motor will jump from torque surges. This usually causes smaller inverters to shut down or burn out. If your inverter does run it, and the motor does not say "thermally protected", monitor its temperature for overheating. If the surges are severe don't use it. This is an inverter problem not a motor problem. It may have to do with the voltage regulation design (or lack thereof) of the inverter and it's more likely to happen with smaller inverters. Use a different brand, or use a larger inverter. Plug in capacitor line noise or "dirty electricity" filters. Newer electric blankets with adjustable power levels are known to fry. SoftHeat Low Voltage™ series from Perfect Fit Industries do work. Consider skipping the inverter and buying an electric blanket that plugs in to DC power directly. Switching to DC will generally eliminate the potentially harmful exposure to alternating magnetic fields and electric currents. These devices sometimes have problems: Laser printers often do not work properly. Computer UPS units often detect a square wave as bad power and switch to battery backup (which is hypocritical since they put out the same bad power). Induction motors (the ones without brushes) run about 20% hotter than normal according to the Internet. This is usually within the tolerance of the motor. Motors naturally run hotter during low voltage brown out conditions anyway. Cheap devices may not have much margin for error. If you live in a hot climate and intend to use an inverter for long term use, consider a pure sine inverter. Also, in long term use applications, if a significant portion of your load is from induction motors, the increased motor efficiency of a pure sine wave may be cost effective. Not all modified square wave inverters are the same! Motors are sensitive to the kind of square wave output they're used on. A low cost inverter design combined with high load and low inverter input voltage will make an inverter reduce the dead time (the middle step) in the output to increase the AC voltage which makes its output closer to a square wave. This can make motors run hotter and most motors should not be run at all on a square wave. I tested an 800W Black and Decker inverter and the output became a square wave at full load. That's the worst I've seen. The Harbor Freight inverters go a little closer to a square wave than I'd like to see, especially some of the smaller (<1000W) units getting to <15% dead time. At least some of the AIMS and larger Power Bright inverters have internal voltage regulation rather than voltage regulation using output dead time variation and their outputs are fixed at about 25% dead time. That's a better design. Some devices which have active power factor correction (APFC) power supplies have been known to have problems, and are damaged in some rare cases. Most devices work fine. APFC is getting more and more common with switching power supplies (like TVs, projectors, game consoles, and desktop computers) and sometimes even smaller devices that use under 200W have it too. If the power supply has a 110/220 volt selector switch on the back then it does not have APFC. With APFC there is a capacitor inside that charges and discharges with the AC input voltage and this can cause a buzzing sound. Light dimmers may not dim correctly. Some analog TVs, stereos, or amps with poor filtering will have a buzzing sound in the audio or visual interference. Microwave ovens usually don't put out as much power (or draw as much), but almost always otherwise work fine. Some clocks won't keep time correctly. Devices which generate a buzzing sound. This is usually just annoying but in some rare cases indicates harm. If the noise comes from a motor or transformer it's harmless vibration of the coils. Medical equipment like oxygen concentrators. AC powered smoke detectors may be damaged and possibly become battery powered only. These devices always work just fine: Plug in transformer DC power supplies (wall warts) Plug in switching DC power supplies (more advanced and efficient wall warts) Lights All electric heating devices without fancy controls, like space heaters, hair dryers, and toasters. Transformer based linear power supplies. All medium and small switching power supplies (without APFC). Laptop power supplies. All computer power supplies with a 110/220 volt selector switch on the back (these don't have APFC and are more efficient than APFC models). Nearly all TVs, VCRs, DVD players, screens, etc., (based on the previous two bullet points). These devices work better on a square wave: Brushed AC (universal) motors, such as angle grinders, and variable speed kitchen mixers. Cheap transformer based car battery chargers may be less likely to overcharge the battery. Filtering the output: It is possible to make a small filter to get rid of the voltage spikes that are causing buzzing or problems for a certain device. This is best left for an electronics hobbyist as the filter should be made specifically for the device. Don't just put a capacitor across the output, this tries to filter the entire output and makes the inverter create more heat and could harm it. Put a small high wattage resistor on the input before the capacitor. Even a 2 ohm resistor will draw 70 amp current spikes. Some people say to use a 1:1 transformer as a filter on problematic devices, but the resistor and capacitor method should accomplish the same thing. The transformer method may be more efficient. Be careful using inductors as filters. Although they can be great if done correctly, they can create high voltage spikes if the load suddenly changes, and high frequency ringing when combined with capacitors. Installing an inverter and connecting to your house power Always turn off the main circuit breaker to your house while the inverter is connected to a building's power (unless it's a grid tie unit). Backfeeding in to commercial power is a hazard for utility workers, especially in rural areas. If commercial or other power is turned on while the inverter is turned on (or even turned off) the inverter will likely be damaged. Do not parallel inverters which are not designed for such. They can't be synchronized like generators. Always install the inverter close to the batteries. If the inverter must be far from the batteries, then use thick enough wires so that the voltage loss does not exceed 0.5V at 12V. Aluminum wires will be cheaper and are a good choice if installed correctly. Also, switching to a 24V system from 12V will allow for four times the distance from the batteries with the same loss when using the same size cables. Use longer AC power cords and not DC cables. The DC power cables should connected to a marine ANL fuse before leaving the batteries and going to the inverter. Make sure the interrupting current of the fuse exceeds the short circuit current of the battery bank. When sizing the battery cables, check an ampacity chart for open air conductors to make sure the wires are sufficiently sized and have a high enough insulation temperature rating such as 105C. Paralleling two cables of 3 AWG sizes smaller may be cheaper and give a little bit higher ampacity rating. Correctly sized 120VAC power cords should be used. Use 12 AWG or bigger wires on a 4000W inverter. More potential hazards: When connecting an inverter output to a building's power, be aware of some things. Many people use male to male "suicide cords" to plug power in to a building. This is a hazardous connection and children should not be allowed to have access to it. If the inverter or generator puts out more than 1800W at 120VAC and doesn't have its own 15A breaker, the possibility of overloading a standard 15 Amp circuit exists. The circuit breaker in the fuse box can't protect against overloads from devices plugged in directly to the circuit being back fed. Having a fuse on the suicide cord is recommended. An 18 AWG copper cord in open air will start feeling hot around 15 Amps. Look out for air compressors, space heaters, and other high power devices that may be plugged in to the back fed circuit. If two houses are being powered from the same inverter or generator, remember that the neutral lines of both buildings are already connected. If the polarity of one of the back feed cords is reversed, a short circuit will exist from the hot wire of the back feed cord through the unfused neutral line of the building, which is connected to the neutral of the other building and back to the power source's neutral. In order to supply power to both sides of a split phase power system people sometimes hook the power in to a 220V socket and bridge the 220V hot wires together. This can be hazardous as it doubles the fusing capacity of the circuit and can result in doubling the maximum rated current going through the unfused neutral line (a 20A 220V outlet becomes 40A). It's better to connect through a regular 120VAC socket and then short out the terminals on one of the 220V sockets in the building to power the other phase. Do not connect 240V to a building's power unless the generator or inverter has a split phase 120V + 120V output and there is a secure neutral connection. If the neutral comes loose there will be 240V on the 120V circuits. Isolated output: Many inverters sold today feature an isolated output. If an inverter does not have this feature, and it uses a standard H bridge output design where both outputs alternate between 0V and 145VDC, then a shock hazard exists. The AC outputs are electrically connected to the DC input, which connects to your batteries, vehicle, or solar array, etc. When it's hooked to a building's power, that building's neutral line is hooked to earth ground. Because of this, there exists a 120VAC half wave shock hazard from the DC side of the inverter to building and earth ground. Since the ground prong is often hooked to the DC side, shorting the neutral to ground will usually damage a non isolated inverter as this bypasses its over current detection. If a non isolated inverter must be used for back feeding a building, do not use a 3 prong extension cord and consider the DC input side to be dangerous voltage. To test for non isolation, put a multimeter on the diode check function, with the positive red test lead on the inverter's DC negative connector and the black test lead in one of the AC output terminals. If it reads anything less than 1999mV then it isn't isolated, otherwise it probably is. Insure that the DC side connections are tight and that they do not become excessively warm during loaded operation. As the load doubles, the connections and wires will become four times as hot. Shipping: Shipping is from Illinois. I can usually ship the next day. I am willing to combine all shipping! If there is a Buy it Now or Best Offer item, you can offer 1 cent lower and I'll accept, then you'll get an invoice and a shipping quote from me so you can pay later for all your items at once instead of being forced to pay right away for Buy it Now items as eBay now makes you do. Contact me for International shipping to get a shipping quote. You are responsible for all duties. If it gets lost in the mail internationally and the tracking number shows that it has disappeared, I am not responsible. Only USPS can ship to P.O. boxes! Returns: Returns accepted after 14 days. You pay return shipping. If the item is listed as working and it is broken, then I pay return shipping.

Price: 695 USD

Location: Peoria, Illinois

End Time: 2024-11-18T05:51:02.000Z

Shipping Cost: 0 USD