Tripp Lite IS250HG 250W Isolation Transformer Hospital Grade 2 Outlet UL2601-1

Performs very well, less than 0.1mA across a line-ground short circuit (see photo). The product ships with a grounding receptacle, which creates a parallel path to the single point ground via the receptacle screw and chassis. If you care, installing an isolated ground receptacle will eliminate the small ground loop. But in a real hospital setting, the redundant ground paths may be required by regulation.

This small isolation transformer reduces noise very well. Where I live, the internal electrical components of my laptop make painful amounts of noise when it is plugged into the wall. This transformer eliminates noise and other problems that affect the performance of my laptop. I like this transformer very much!

The unit works but it desperately needs an indicator light to remind you it is on. I drilled a small hole in the 'front' and installed a A/C neon light. The light is a great addition instead of just leaving the unit on all the time if (when) I forget to turn it off.

I recently purchased one of these units new from an independent Amazon seller, and after just receiving it, even with no load attached to it (no device connected to it's built-in sockets) I heard a hum from the Tripp Lite unit, and it vibrated. It was simply plugged into a grounded 3-pin wall outlet and turned ON. I contacted Tripp-Lite and was told the unit should NOT vibrate, and was sent a new one as a replacement, without any problems from Tripp-Lite, at all. The new one doesn't vibrate. There's still a very slight hum, but nowhere near what it was with the one that also vibrated. Tripp-Lite was very nice about it. This is the way American companies used to be, with warranties. I'm glad I purchased a Tripp-Lite Isolation Transformer. A bit more expensive at first, but worth it in the long-run. If anyone else has one that vibrates, ...and it's still under warranty... Contact Tripp-Lite and get it replaced.

I have what is, apparently, a delicate piece of electronics for cleaning the air in my house. It runs continuously. I had it on a good surge protector. Every year, I had to send the device back to the manufacturer for repair because it stopped working. (The repair typically cost $125 per episode.) Three years ago, I put the device on a Tripp Lite IS250HG; it has never failed since. Apparently I have dirty power here. As there is plenty of wattage capacity in the IS250HG, I also put my Hi-Fi and some other small devices on it as well. The IS250HG that I bought from Amazon was manufactured in Taiwan. Recommended.