ZHENGXI 10 Amp Adjustable Voltage Regulator 1000W Variac Variable Transformer 110V Input, 0-150V Output

Wired incorrectly? I received my unit yesterday, and had read on here where the output outlet was wired backwards, with the neutral and the hot wire reversed. So I plug my unit in, and plugged in an outlet tester, and sure enough, it show the hot and neutral reversed. I have seen where some others have open the unit and unsoldered the wires and reversed them on the outlet plug. But I checked the cable that came with it, and found that the cable pins on the EIC connector were backwards. I plugged in an extra cord I had, and now the unit is working correctly. I would not unsolder inside, rather get a new plug from a hardware store, and reverse it there. So the cable you now have is wired correctly, in case somebody else gets it, and use it for something else. Other than that, the unit seems really nice, powers up. I think it’s gonna work great. So reverse the hot and neutral at the cord at the plug that goes in the wall, instead of doing it inside of the unit.

My unit arrived with the plastic voltage adjustment knob broken into several pieces. I was going to pack it up for return, but since I really needed this for a repair, I kept it and ordered a replacement knob on Amazon.Functionally, this unit works fine. I appreciate the all metal construction and digital volt meter. I really wish it had an output current meter (ammeter) and may add one.However, as several reviewers have noted: The provided power cord INVERTS Neutral and Hot!! This is a major shock hazard! Check your cord and if it’s wrong, THROW IT AWAY!I opened my unit up and the internal wiring is CORRECT, so you’re good if you use a correct power cord.I had read other reviews mentioning this problem, but stupidly began using this unit for my repair project without checking this first. I accidentally brushed the unswitched “neutral” and got a nice buzz! So, word of warning: Verify the outlets are correct before using!Also, once I opened the unit up there were several things that I tweaked: (1) The red wire that runs to the wiper mechanism can get twisted into the winding housing. A few other reviewers mentioned this too. A couple zip ties solved that problem. (2) The connection from the red wire to the wiper assembly was frightening close to the metal shaft that connects to the adjustment knob. Bending the connection slightly and wrapping the shaft with electrical tape solved that. (3) The biggest issue is that the metal adjustment shaft is electrically “floating” — it is not grounded and therefore an internal short could energize it. The outside knob is plastic, so it should be “safe” but since the bare shaft protrudes out the case at least 1/4 inch, this could be a shock risk. I added a ground wire to the M6 nut at the end of the shaft to assure it is grounded.

Overall nice design, but poor wire connection technique inside (the wires soldered to tabs on the connectors have no mechanical connection, just solder). The power cable shipped with the unit was fitted for Japan or UK so the 5-15P plug supplied has the line and neutral connections reversed. Beware of it, and just know you'll have to buy an IEC320C13 to 5-15P cable that is wired for US/Canada to operate this thing safely. You might get a nasty surprise when working on appliances plugged into this device otherwise.

I bought the smallest unit because of the limited space on my test bench. It will provide enough adjustable ACV power for most of what I normally test. After reading other reviews, the first thing I did was to plug an AC outlet tester into the output and it identified a hot/neutral reverse. The problem seems to be with the how the cord is wired, so the best fix for me was to throw away the cord that was supplied and use a spare that I had, which was wired correctly and it took care of the problem. Thanks to the other reviewers for pointing it out! Pretty solid metal construction, and the AC voltage readout is very close to the reading from a true-RMS DMM checked at no-load conditions. I did need to take the unit apart, since I had to remove the top handle for easier stacking with my bench equipment, and the interior construction looks pretty good. The only thing I noted was that it uses a 2A circuit breaker, assuming I read the markings correctly of course, so it's not clear to me that this unit would deliver 500W continuously, even at the highest voltage output. That's probably okay my needs, though, and I still think it's a very good value overall.

Neat little variac. Love the handle on top. Measured voltage, with my meter (Fluke), at output is roughly 4VAC over what the display reads. The polarity of the 120VAC output was backwards. I just opened it up, swapped the hot and neutral and resoldered. Other than, love it.

First one that I got had a broken control knob but had really nice packaging, The replacement had a good control knob but the post it connects to was smashed in and broken and the packaging did not have enough packing to protect it.

The cord is wired backwards as everyone has pointed out. It has been replaced. That fixes the safety issues, but causes the hot/neutral to be backward on th output sockets. So re-wired that. The digital display gauge is very inaccurate. At higher voltages it is only off by 2-3 volts, but at lower voltage it is bad. When the digital display says 12 volts, the unit is actually delivering 18v. This behavior was the same on both the 1000w and 2000w units I tried. That being said, unless you are looking to spend $500-$600 on one of these, this is not a bad option if you are willing to open it up and tweek it. I orriginally rated it as 1 star and was going to return it, but have decided that now I have re-wired it (and tested), some blue tape over the digital display and a multi-tester to set voltage will work for my needs. Overall mechanical build quality seems fine. The adjustment knob feels solid. Nice box and carry handle. All things considered, I have upped it to 2 stars.

Did not work. Had to fix it first and then it was great.