208/230 Volts vs. 240 Volts

Single phase ratings are usually written as such: "120/240 volt" or "120 volt" or "240 volt"

Three phase ratings are usually written as such: "208/230 volt" ; "208/240 volt" ; "208/230 - 460 volt" or "208/240 - 480 volt"

Somewhere on the rating should be listed the phase of the motor so you know for sure what it is you are looking at.

The 208 systems are not common. Most common is the 240 volt system, be it single or three phase. Some older ratings read "230" but this is the same as "240" volt. Almost all the new rating you will see written will be "120", "240", "480" or "575". Looking at some of the older ratings listed in books you may see "200", "208", "230", "240", "277", "380", "400", "415", "460", "475", "480" and "575".

Some of these are European voltages which are usually at 50 Hz (cycles per second) as opposed to United States standard of 60 Hz. Some motors are rated for both 50/60 Hz but will have slightly different Rpm's and amperage draws for each. Some equipment is also multi-tap which can be run on a host of different voltages.

For most common USA equipment, "110/115/120" are interchangeable as is "220/230/240" and "460/475/480".

Hope this helps. When looking at this stuff you need to watch the "phase" so you are comparing apples to apples.

if you want a good compressor , buy a quincy, they make I-R look like junk. they have a real crank, not a pin hung out in the air to break off, I have both kinds . will replace I-R with quincy.

george

Most utilities don't allow "across the line" starting of motors over 5 hp single phase without permission. (This is seldom enforced) The bigger question is if you need three phase power is it available and is affordable. Getting three phase power can be a major expense to run a single tool. If the tool of your dreams only come in three phase power configurations you can use what is called a rotary phase converter. Good luck