As Gene already mentioned, why are you looking for a transformer at all? The "split" in "split phase" means that you can connect loads between either hot and the neutral to get half of the overall voltage. So if you have 240V line-to-line, you will get 120V line-to-neutral.
I can think of two reasons why you might actually need a transformer, but you don't give enough information to know if either one applies. Reason #1: You really do need 100-110 volts, and 120V is too much. I don't know what kind of load you are trying to run. Normal equipment intended to run on North American power typically accepts from 120 +/-10%, which would be 108 to 132 volts, and would always work when connected line-to-neutral on normal North American power. (In fact, the low limit might be more like -15%, and it would run OK down to 102 volts.) Is your load something non-standard that goes poof at 111 volts? If so, what it is? Note that some equipment that is rated for 100V has that rating because it is used on 50Hz power. Motors and other inductive loads that are rated for 120V 60Hz (normal US power) are sometimes dual-labeled for 100V 50Hz, which is common in Japan and a few other places. Motors will run faster on 120V 60Hz but otherwise should be OK. Contactor and relay coils will operate almost exactly the same on both kinds of power. If you do have something that needs a maximum of 110 volts, and you have 120V line-to-neutral power available, the smallest, lightest, and cheapest way would be to buck the power down by 10 or 12 volts. You could use a 250VA 120-to-12V transformer instead of a 2500VA 240-to-100V transformer. Reason #2: You don't have access to the neutral. For example, many electric dryer outlets in American homes are wired with two phases and ground, but not the neutral. In that case you do need a full capacity transformer. The transformer you linked to would work, assuming that your load is less than 2.5kVA. (Note that some people might suggest connecting your 120V load between one hot phase and the ground prong on the dryer connector. This is unsafe - if you have to ask the question, you should not do it. (An experienced person MIGHT be willing to do it, in a one-time special case with extra care taken to ensure safety - but in general it is a very bad idea.) On Thu, Dec 29, 2011, at 08:54 AM, Clint Washburn wrote: > What type of transformer would someone use to connect to the American > Split-Phase 240 volt system to get 100-110 volt output? Would one like > this > work? > http://www.ebay.com/itm/Nunome-2-5-KVA-Transformer-/110344460317?pt=BI_Circu > it_Breakers_Transformers&hash=item19b10ad81d > -- John Kasunich [email protected] ------------------------------------------------------------------------------ Ridiculously easy VDI. With Citrix VDI-in-a-Box, you don't need a complex infrastructure or vast IT resources to deliver seamless, secure access to virtual desktops. With this all-in-one solution, easily deploy virtual desktops for less than the cost of PCs and save 60% on VDI infrastructure costs. Try it free! http://p.sf.net/sfu/Citrix-VDIinabox _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
