4 ms·
US Power is typically 240v split-phase, a single phase, not two phases. The transformer is 7200v to 240v. The Neutral line to your house is center tapped on the
by johann8384 3y ago
US Power is typically 240v split-phase, a single phase, not two phases. The transformer is 7200v to 240v. The Neutral line to your house is center tapped on the transformer giving you 120v from Hot to Neutral and 240v from Hot to Hot. I have L14-30 and L5-30 outlets throughout my house and property for example which lets me run higher voltage/amperage workloads more easily. My workshop has an isolation transformer which is 240v primary and 120v secondary. This allows me to run 80A of 120v "stuff" in my workshop but it's a 40A 240v load from the perspective of the main panel in the house.
- mrcommentwriter 3y agoInteresting, I haven’t heard of anyone doing this before. What is the advantage? Assuming 120v loads are split reasonably equally between each leg of the 240v phase, the load will mostly be on the 240v circuit because both legs are connected in series. The neutral back to the transformer is only used to carry the difference between the 120v load on each leg of the phase, and also to keep the system grounded. I guess if you had a panel close to load capacity, as well as a single very high amp 120v device, the transformer could enable some more capacity by ensuring the load was distributed equally between the phases. However at that point a service upgrade would probably be necessary anyway based on the load calculation rules in the code. Also high amp 120v devices are quite rare as far as I know, so I was wondering why you went with this unusual setup.