# Make Your Old Motor Energy Efficient

 There is a way to make a standard AC electric motor run 10 to 20% more efficient. If the motor like on a furnace fan has no capacitor wired in or has the capacitor only for starting purposes and is the brush-less type with a solid core rotor ( no windings on the rotor) then you, or you can have an electrician do this, just by following these directions. The procedure is easy but sometimes the mechanics is not so simple.  This is something that is done to the new energy efficient motors and they do it even a little better with the windings but this will work with just about any old motor if you can understand that the common electric motor has two sets of windings, one for the running and one for starting the motor.  The start winding is only engaged when the motor is stopped or at low speed once the motor gets up to speed there is a mechanical switch that because of centrifugal forces will cause a switch to be opened and the motor only uses the main winding and the start winding uses no electricity just sits until the next time the motor is needed to start up.  They found that using a smaller size capacitor across this switch would cause a small current to run through the start winding all the time. It being through a capacitor was out of sync with the main winding but the start winding is wound out of sync and ends up working to spin the rotor causing inductance to change on the main winding to cause the amps to go down more than the amps going thru the capacitor. With an average 10-20% drop in electricity use.  To do this usually you have to go inside the motor, sometimes can be done out side, right at the connections, if you can see both electrical contacts, that are closed when the motor is stationary, the start switch. Simply attach a wire to each of the terminals corresponding to the contacts. one on each so if put together would bypass and short the switch. To each of the wires is where you connect the capacitor.  To find the size the general average is 10 MFD (Micro farad) per horsepower. And the voltage rating should be 3 times that applied, so a 120 volt motor gets 350 volt or above capacitor. Many are rated 370 to 440. Volts.  This is the part that is good to be done by the electrician or someone who knows how to use an amp meter and can do a little averaging. If you have a motor to do, before taking it out to rewire, check the amps running under load and record and to see how hot it is running, just by feel on the main frame. (If this is a furnace blower, it might be hard to get it right as the amps vary with the furnace filter door open).  Try to get as accurate a reading as possible, even if you have to run a loop of wire out and semi close the door to restricted air how. To get a good reading. Then remove the motor and rewire it for your new capacitor style.  If you have to disassemble the motor, be sure to mark the position of the end bells on the frame remove the 4 bolts and carefully tap evenly all around the switch end bell off from the frame. If it is the bushing type it should be easy If it is the bearing type then you have to be careful not to disturb the bearing to much and be careful not to break the switch plate as the wires only come out so far.  Sometime after you have it apart then you can see the terminals on the other side that line up with the switch contacts for your new wires. It could be that if you were doing a few motors the same you would not have to take the others apart. Just hook you two wires into the conn block.  If the motor has a multi voltage connection that will run both directions, sometime you can trace the switch wiring and just tie in you capacitor leads just to each side of the start winding switch.  When reassembling be careful to tuck the wires around the back side of the coils as not to be near the centrifugal switch on the spinning rotor. Also that the switch is in the right adjustment that the contacts are closed when the spool on the centrifical switch is in position and not touching when you squeeze the centrifical switch to simulate the running position.  You could clean the contacts with very fine non metallic sand paper if they appeared dirty, it might save aggravation of repair later. Speaking of aggravation later, if your motor is the bushing type that has oil holes then it is a great idea to use some of the MT-10 or Dura Lube mixed 50% with reg oil for oiling your motors. Bushings love it and you will save the motors life by doing so.  Never use WD-40, 3 in I oil, or any oil that has a penetrating action in a electric motor for the bushings, it will cause the oil there to dry up and seize the motor.  The 3 in 1 brand made for electric motors is ok but all you need is #30 non detergent oil and mixed with the engine oil treatment will save a repair job in the future.  Make the wires long enough to go where you want to mount the capacitor and then some. Be sure to tape and insulate well where the wires comes near the motor. The capacitors are attached with slide on lugs or screw terminals only, never solider direct on the capacitor, it may damage it. Then reinstall the motor and try different capacitors around the size recommended, 1/3 HP try a 2, 3,4 or 5 MED watching the amps draw the size with the lowest amp draw is what you want, but do not go much bigger than 1.5 MFD per horsepower. Also you should just feel the motor after it h as run an hour or so and if it feels hotter than before you wired it, cut back on the MED size even it the amps are a little higher, it will still be less amps than it was drawing originally. Most times you will notice that the motor is cooler than before and this means the motor will last longer. Excess heat causes the motor to lose its lubrication and also dry out the windings causing early breakdown. The cooler is because of more efficient use of the electricity. If it is running cooler you know you have the right size. On some motors the gains are better than others. It depends on the load and original design, if the amps go above the original even with a small size capacitor then the winding will not permit this principle to work. If using a amp meter you may notice that the amperage of the main winding and the amperage thru the capacitor in to the start winding actually add up to more than what is being fed thru the supply line. It was strange when I first noticed this and took a while to figure it is because the voltage loops around thru the capacitor in this out of synchronous so it actually reads higher when added. But it is what comes thru the main line you pay for that is where the savings come from. Please do not attempt this unless you are familiar with electricity and mechanics. This is for your information and is just included free with the hydro boost Manual I did not invent this just observed it and share it now to help get energy losses down. It is not for all motors and we take no responsibility for damage done by trying and results there of When dealing with electricity it is your responsibility to follow any and all codes. This will work and has worked on many motors for years and is part of the design of new energy efficient motors. I hope it is of help to you.