WZRELB 7000W Pure Sine Wave Inverter, 24V DC to 120V 240V AC, 4 AC Outlets, Hardwire Terminal, 91.6% Efficiency

UPDATED: Bought this inverter as a means to provide emergency power to my house through a mechanically interlocked main breaker. The generator connection is a 30A twist lock, so I had to wire the inverter with a breaker and means of connecting to the twist lock. It has a hard-wired set of connections to accomplish this. The inverter is sturdily built, although it’s clearly not a Victron or similar. The format I purchased is the longer, narrower one, 24v split-phase 7,000 W. As mentioned, it has a set of hard-wired connections for outputting 30A of 240v power (2 hots, a neutral, and a ground). It also has a hard-wire terminal for 240v power similar to the European standard, but I didn’t have a need for this and didn’t do anything with it. You can read the specs to get the features and safeties included. However, I doubt seriously that this inverter will supply 7kW continuously, even in cold weather. That’s ok for me (not ideal, but OK) because it was the only one of similar capacity with dimensions that would work for me. I needed to mount it inside a NEMA outdoor panel, 24x24, and this thing barely fits with a tiny bit of room to wire it. However, since installing it I have performed a few tests to see how far I could push it. While I did not start sufficient loads to get to 7 kW, I was at about 6.2 kW and voltage had sagged to 115v per leg, 230v total. The inverter claims surge power of 14,000 W, but seems difficult to believe. I didn’t push it any harder during this first test, and I was going off of the unit’s own display for the voltages and currents. I have not had a chance to use it for more than a few minutes, so don’t know the long-term reliability of this “reliable inverter,” but I’d say it’s OK for the price. My next test involved charging my car with a level 2 charger that uses about 5.8 kW. I turned off all other loads. Of course, this load needs to run for a while, so I thought it would be a good test of the inverter at a high continuous load. Right off, it's clear that this inverter generates a LOT of heat, although that may be because if the large load. Based on amps in and amps out (as measured with my amp meter), I did get the claimed 90% efficiency, although just barely. This means that 580W are coming off of the inverter. Even at 75°F ambient, the temperature on the display read 62°C before it was stable. My installation is in a hot climate, so doing this load at 90°F or above was simply untenable. Yes, you can do it, but only for a few minutes until the temperature climbs so high that the unit shuts down and starts beeping until it cools and you turn it off and back on again. Yes, I understand that even Victron inverters derate based on temperature, and that the given rating is largely aspirational except at low ambient temperatures, but WZRELB's literature doesn't give a clue as to what the derate might be at various temperatures, which seems like a gaping hole in their literature. How can you size an inverter for what you need to do when you need to do it when you don't know what it's capable of AT YOUR OPERATING CONDITIONS? Please WZRELB, publish this information. Another thing, and maybe it's just my unit, but at the 5.8 kW load, the unit had a persistent electrical buzz regardless of the ambient temperature. This is not promising from an inverter that claims a continuous duty of 7 kW. Heat management could be far better in this unit. Taking the cover off reveals that only a tiny portion of the fan inlets are positioned to draw air through the heat sink. The rest draws air through the empty space in the cabinet, which makes some sense, but very little considering that the heat sink is so massive and has surface area to give up heat to passing air. They really need to improve the fans on this unit. A round fan with, say, 1/4 of its inlet area positioned over the heat sink (if that) will move far less than 1/4 of its air volume through the heat sink. Some sort of preferential ducting in the unit, or some other way to actually make the heat sink's surface area effective would be really nice. Overall, I wish it were better. However, it did fit within the space I have, with the only other similar option costing about 3X as much (Victron Quattro) and possibly requiring an autotransformer to split the phases. It also starts and runs even the largest 240 V loads in my home, including a 6.0 cuft dryer and a 5 TR air conditioner (not simultaneously and clearly not for very long if the weather is warm), along with the regular stuff (full-sized refrigerator, lights, tvs, etc.). Run time is, of course, limited by my battery storage, but I can get by when the power goes out and, even if I need to run the a/c or the water heater for a bit, I can. I may try the Victron at some point, but for now, this will fit the bill and is economical.