Bests & Worsts Reviews from Amazon

I purchased the 3000 W ELC transformer in order to use a 240 VAC espresso machine (1150 W) and a 240 VAC coffee grinder (150 W) that I brought back from Australia on the 120 VAC kitchen outlet in the US. According to the advice to allow a 50% overhead in the rating, a 2000 W unit should have been adequate. However, I bought the 3000 W unit to have even more margin. It costs only $10 more, and is no larger in physical size (but it weighs a few pounds more) than the 2000 w unit. I inspected it closely and have used it for several days. I am very pleased with it. I have one very minor issue with the power cord that caused me to withhold the 5 star rating. See more below. Unlike some, ELC's description of the unit on Amazon is complete and the pictures are large and clear. I originally ordered a different transformer, but I canceled the order after I learned some of the details that were missing from its description and pictures. These missing details were provided sporadically in answers from customers and from the seller. ELC has their act together better, which enabled me to order with more confidence. The unit runs noiselessly, without any noticeable rise in temperature. It did have a slight odor when I unpacked it, but that disappeared once it was out of the box and had aired a bit. Keep in mind that I am using it at less than 1/2 of its rated output, and I use it only intermittently, for perhaps 10 minutes at a time. Your results may difer. The transformer itself is toroidal shaped, which is more efficient and reduces emission of electromagnetic field, compared to a traditional non-toroidal transformer. (It is more difficult to manufacture a toroidal transformer.) The better efficiency contributes to the much lighter weight compared to many of the other transformers of the same rating that Amazon sells. Based upon electrical measurements, the unit appears to be wired as an "auto-transformer". The added efficiency of an auto-transformer can further contribute to a savings in weight. However, it means that the output is electrically connected to the input, not just inductively coupled through the core of the transformer. My measurements indicate that for the step-up mode in which I am operating, the neutral of the 120 V input appears to be at middle potential of the two power conductors of the 240 V output. That is not what is what is expected by foreign appliances, but is typical for a US 230 V circuit, in which both of the power conductors are not at ground potential (neither is neutral). Some have reported GFI issues using other transformers overseas, perhaps related to this feature. I am operating the unit on a GFI protected circuit and have had no issues with the GFI or my appliances. You results may vary, depending upon your appliances and house wiring. The unit appears to have a reasonably good quality of construction. All solder joints are covered by heat-shrink tubing, so they can't be closely inspected, but they look reasonable in size and shape of the solder joint. Almost all the fittings on the front and back, and the feet, are doubly secured in place by a generous applications of hot glue inside the case. I was drawn to this particular unit by the good ratings, and by the power cord, which appears in the picture to be, and is described as, heavy duty. It appears to be heavier than those on many of the other transformers offered by Amazon. Now that I have it in hand, I see that it is a 3 conductor, 14 AWG cable, which is moderately heavy. The NEC rates such cable for 15 Amps continuous service. For this transformer operating in the step-up mode, 15 A corresponds to a load of 1800 W or less. At an output of 3000 W, the current in that cable would be 25 amps or higher. (Actually, the rating is more accurately stated on the back of the unit as 3000 VA, not W, which puts the maximum current at 25 A.) That amount of current might also exceed what can be provided by a typical 120 V house circuit breaker and wiring. Even with the recommended 1.5 factor for a safety margin, the current would be more than 15 A in the step-up mode. The power cable is undersized for step-up operation. On the other hand, if you're operating in the step-down mode, the cable is adequate to provide more than 3000 VA. If you're considering using the the 5000 W (VA, really) largest unit offered by ELC, then I suggest that you first contact the seller to learn the size of its power cable. It appears in the pictures to be the same as for the 3000 w unit which would make it further underrated for the set-up mode, and marginal for the step-down mode. I am using my 3000 w unit at 1300 W, which would correspond to a current of 11 to 12 A, so the cable rating is not an issue to me. However, I have withheld the 5 star rating because I feel the supplier should either provide a heavier cable with the unit, or provide a warning about using it for continuous loads above 15 A. In summary, the ELC unit seems to be an excellent device. However, if you are using it at high loads without margins you may find that you have concerns related to the power cable rating or house wiring adequacy. The neutral wiring arrangement of the auto-transformer may cause difficulties in some unusual situations.