Power Bright APT1200-12 Pure Sine Power Inverter with Automatic transfer 1200 Watt continuous / 2000 watt Peak 12 Volt ETL Approved under UL/CSA Standards

This item works great. I haven't yet tested it down to the 9.5vdc lower limit. I initially had a problem with it cutting out on a freshly charged 12vdc 18AH battery. It would rapidly cut out and turn back on even with no load. I put a volt meter on the battery and the voltage was varying from 12.8 down to 11.5. In the end, the battery was not fresh enough to hold the voltage higher, so it may have been dropping below the 11.5vdc measurement of my DVM and I wasn't able to see it due to the meter may have been averaging the measurement. I have now had it in place for a trip in my camper (with a new deep cycle battery) and it performed well. I use it to run my refrigerator going down the road. The automatic transfer switch feature really makes this stand out. No more plugging and unplugging when switching to shore power.

I gave the APT1200 four stars because it seems to work well and does what it does. It's heavy (lots of heat sinks) and of good construction. I did not open the unit other than on the black plastic AC wiring panel.Mine did not come with any cable restraints for the AC wiring.I installed this unit into my RV, as it most likely a very common installation.I bought a 50 foot extension cord and chopped it in half. In the APT1200 transfer switch wiring, I wired the black wires to the two LINE lugs, the white wires to the two NEUTRAL lugs and both green wires to the single GND lug. Both of the other ends of the extension cord were routed into my RV power center.My RV only has a single breaker for all of the outlets, etc. (Converter/charger is on another, as is the roof-top air conditioner). This made wiring really easy actually. I wanted an installation where the outlets would get power from the inverter or shore power (via the APT1200 transfer switch) but so the Air Conditioner and the Converter/Battery Charger get power *ONLY* from shore power.I wired the input to the APT1200 (that extension cord) by cutting off the plug (I had left the plugs on as a way to know which cable was which) and wiring the black wire to the breaker lug for the outlets. I then cut off the plug on the APT1200 output and wire-nutted that black wire to the black wire that was previously connected to the breaker. Now, instead of the LINE (black wire) going from the breaker to the outlets, it goes from the breaker to the APT1200 and then to the outlets. Both white wires from the APT1200 were connected to the NEUTRAL buss bar in the power center. Both green wires were connected to the GROUND buss bar in the power center.I tested the APT1200 at the RV outlets (115-118V AC) and it was good. I flipped the breaker on for shore power and the APT1200 blipped the transfer switch on and right back off. It did this several more times, about 20 seconds apart until I shut everything down for troubleshooting.Cutting to the chase: I found that the LINE (black wire) and NEUTRAL (white wire) were swapped, but not by me. After disconnecting the output wiring from the APT1200, I did some simple testing with my digital multi-meter. With the unit fully powered (DC and AC), I checked the voltages directly on the input and output terminal lugs in the APT1200. The input was correct, LINE and NEUTRAL gave me ~118V. LINE and GND did the same. NEUTRAL and GND gave me zero volts. All good. On the output, LINE and NEUTRAL gave me ~118v, but LINE and GND gave me ZERO, while NEUTRAL and GND gave me ~118v!!! I triple-checked the screen printing on the APT1200 board and I was definitely reading it correctly. It appears that the screen printing on the board is wrong.What was happening with the APT1200 inverter is that when the transfer switch transfered, it was swapping LINE voltage directly into the NEUTRAL buss. That's commonly referred to as a "dead short". Built-in protection then removed AC power (internal in the APT1200) and then it would try to transfer again (into a dead short again)... and repeat.After I swapped the black and white wires at the APT1200 terminal lugs, the system has been working flawlessly. On shore power (or generator), the battery gets charged and the outlets get shore power. When shore power goes away, the battery stops charging and the outlets get inverter power.

I must start off by saying I do really want to like this unit as there are many pluses same as many users have listed that make this unit unique, good value to features set, quality based on appearance (although I did not look inside to confirm the build details) and does work well for the transfer switch feature and always on power switch which were the two must haves as it's installed in an RV to power a refrigerator and needed those features to ensure during no AC power the unit kicks in to keep my food from spoiling. I also use it for my backup frig for extra food so it needs to be reliable. So far so good seems to be running well thus far. Time will tell if reliable and will update down the road once we get some time on the calendar to evaluate further.Now for a few minor negatives as others have raised there are no wire restraints on the unit and you have to make your own to cover this. Not a big deal but would be simple for them to add these. Also would have preferred that wire block take the wires from the top rather than the bottom as most existing feeds in RVs or homes would come from the top to wire in. Again minor but have seen a few other companies accommodate from the top. Also only has one ground terminal for AC in and out line connections while most others have 2 one for each line. Makes it really tight fit to tie in two wires to a single ground terminal.The major issue I have is there is a 12v AC leak on the output side on neutral to ground only when the unit is running on DC power as shown in the pic. On AC power there is zero volts on neutral to ground and no issues that way. This was all existing wiring so I know it's not a wiring issue and I tested this directly from the terminal block on the inverter with the wiring disconnected to eliminate a wiring issue. Also this is replacing an existing unit that just died and the prior unit did not have a voltage leak issue. Keeping all wiring the same the only difference is the inverter so clearly points to an issue with the inverter. Would recommend everyone that has one installed in an RV to check your voltage on neutral to ground when on DC power to see if you have this issue. This means it's sending power from neutral to ground which is not good and someone could get shocked from this although it is low voltage. If anyone has any suggestions to resolve this please let us know. Plan to contact PowerBright but their support hours are limited and no Saturday hours so has been a challenge to reach them but will try again within the week. Will share any updates if I get any response on this post.

As described and works great...powers my motorhome fridge when driving down the road (and not running generator) and we not connected to shore power (boondocking or parking overnight at a Walmart). I especially like the fact that the on/off switch is a real switch and not a pushbutton (which would have to be reset every time power was removed). The unit is big...larger than most of the same power rating...I opened it up and the components and build seem to be of high quality.