the motor is from an old air compressor. i want to modify it to run on 120 volts. I know it can be done. I JUST DON'T KNOW HOW = )
2007-10-12 13:38:00 · 8 answers · asked by manolin923 2 in Science & Mathematics ➔ Engineering
Some motors are designed with a choice of voltages. On the nameplate it will say that. It also will have a little wiring diagram there that show which of the (probably four) winding wires goes together and which go to the power. It will show that for 240 and for 120V.
2007-10-12 15:12:21 · answer #1 · answered by Rich Z 7 · 1⤊ 0⤋
First look on the specification plate for the motor. It will say the voltages and the phase that it is designed to operate on. Then if you open the inspection cover (where you hook up the line voltage to) it should have a wiring diagram on the back of the plate for the different voltages. Sometimes this information is on a plate attached to the motor. There should be tags, numbers attached to the wires. If it is a muti voltage motor. You can not change the phase. However you can trick the motor with a device called a phase converter. They sell these at electric motor shops. They are wired to the outside the motor. Most of the time on the line voltage side. They are sold at commercial and industrial electrical supply warehouses. It is not worth modifying the motor itself. I would try to swap the motor for one that I could use on a site like craigslist first.
2007-10-13 08:12:24 · answer #2 · answered by The Answer Man 3 · 0⤊ 0⤋
Like Rich Z, said, check the name plate, while you are looking at the name plate, note the horsepower, if it is above two horsepower it is very unlikely that the motor will be 120/240 dual voltage, and it will probably impractical to use a transformer or have the motor rewound for 120V, as installing a 30A (or larger) 120V circuit will probably cost as much or more than a 240V circuit. . A 20A ,120V circuit can theoretically deliver a maximum of 2400W continuously, (and quite a bit more for very short periods, as when starting a motor) but one really shouldn't use more that about 80% percent of the capacity or about 1920W, since one horsepower is about 745W, around 2.5HP is the maximum, and tripping the breaker while starting could be a problem as an induction motors tends to draw significantly more current while starting.
2007-10-12 21:37:26 · answer #3 · answered by tinkertailorcandlestickmaker 7 · 0⤊ 0⤋
Yes, you just need a 2:1 step-up transformer. Just make sure you get one with high enough current rating. These are common. The problem you may face is the frequency. 220 volt stuff from overseas may be designed for 50 Hz. That will mean it will run faster than it was designed for. Maybe that is no problem for you, but a 20% increase in RPM will have to be considered.
2007-10-12 18:48:40 · answer #4 · answered by Warren W 2 · 0⤊ 0⤋
If you have a 220 motor on a old compressor odds are that it is a 3 phase and no you cannot 110 it unless you have 3 phase in your house or garage. You can try and run 2 hot wires and 1 common, I am afraid of electricity because my mother told me not to play with electricity and when she caught me, she grounded me, ha ha!!
2007-10-12 15:21:02 · answer #5 · answered by mr.obvious 6 · 0⤊ 1⤋
If the motor is a brush and commutator type, usually the armature and stator are wired in parallel, if these connections are re-arraigned to be in series it will work on 120V, if the motor runs in the reverse direction, switch (reverse) the connection for either the stator or the armature (not both) and this should correct the direction. Please be careful !
2007-10-13 05:11:45 · answer #6 · answered by Brian E 2 · 0⤊ 1⤋
Rich Z is right, you need to look at the plate on the motor. If it is unreadable, take it to a shop that rebuilds electric motors and they can help you out.
2007-10-12 16:40:10 · answer #7 · answered by Anonymous · 0⤊ 0⤋
It should start, but vacuum developed would be low. It will also draw more current than a 500W machine designed for 110V would.
2016-05-22 03:40:48 · answer #8 · answered by Anonymous · 0⤊ 0⤋