The single phase motor will have two windings, one in series with the capacitor and the other across phase neutral.
To reverse the direction, reverse the polarity of one winding only and the motor will start in the opposite direction.
I should be noted that it is specific to what kind of single phase motor you have. There are some that are not reversible.
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Just switch the capacitor from one coil to the other;
i.e from the starting winding to the running.Leave the capacitor end connected to the neutral in place , switch the coils in the other end of the capacitor
mohamedone;
Not very good advice. You are familiar with one type of motor which is generally used as an integral part of an assembly or mechanism, not a stand alone, general purpose motor.
The majority of single phase motors in use may burn out and/or explode the capacitor if your advice is followed. I will admit that they may run in reverse for a short time before they die.
Bill
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"Why not the best?"
Jimmy Carter
Thanks for the comment. In fact what you suggest is ture for a start capacitor (plastic cased)which can't stay in the circuit more than few seconds, or it may burn and even explode.on the other hand run capacitrs(metal cased round or oval) are designed to stay
no trouble as long as they meet the voltage requirement.
The capacitor creates a leading or lagging pf, shifting the phase angle to create the rotating magnetic field in need.
What I understood from keith is that the capacitor is
a metallic run capacitor.
Your suggestion assumes that the start and run windings are identical but wound with 90 degrees positional displacement.
If the two windings are not identical, then you will do damage to windings and/or capacitors.
It has a fan at the front of the motor. Where it originally came from, I have no idea. It has no switch, just plug it in and the start capacitor kicks in starts the motor and thats it.
I was looking in the Brook crompton page and I found this:
" Permanent Capacitor - PDA
Standard Design: Direct-on-line starting only, with any spot voltage between 200-250 volts available. Suitable for fans blowers and centrifugal pump drives with light starting requirements. Starting torque is between 25% and 55% of full load torque, according to frame size. Clockwise or anticlockwise rotation of the shaft is available by re-connection. Available in outputs from 0.09kW to 2.2kW, frame sizes PDA63S to 2-PDA90L, in 2 and 4 pole speeds.
High Torque Design: As above but with a higher starting torque of between 70% and 80% of full load dependent on frame size. Available in outputs from 0.37kW to 1.1kW, frame sizes 2-PDA80M and 2-PDA90L, in 4 pole speed.
Variable Voltage Speed Control Design: For use on variable voltage (thyristor) speed control such as fan applications. Available in outputs from 0.37kW to 1.1kW, frame sizes 2-PDA80M and 2-PDA90L, in 2 and 4 pole speeds.
Capacitor Start- EDA/TDA
Available in either Capacitor start/Induction run (EDA) design - vailable in outputs from 0.12kW to 1.5kW, frame sizes 2-EDA71M and 2-EDA90L, in 2 and 4 pole speeds, or Capacitor start/Capacitor run (TDA) design, available in outputs from 0.18kW to 3kW, frame sizes 2-TDA71M to 2-TDA100L, in 2, 4 and 6 pole speeds. Direct-on-line starting with any spot voltage between 200-500 volts available. High starting performances suitable for industrial and agricultural applications of a more demanding nature. Starting torque is between 160% and 300% of full load torque according to frame size. Clockwise or anti-clockwise rotation of the shaft is available by re-connection"
Maybe you need the to do the right connections and wire proper the motor.
So far I have reversed the Red and Black wires from the plug (A & A2). This was advised from another Forum during my searches.
I have also reversed the wires from the Capacitor, but left the other wires in place, this did not work, I then swapped the remaining wires from the terminal, this did not work either.
I then put these wires back to Original and then Swapped the Z and Z2 wires.
Maybe Im missing someting here.
For myself I would really love to know what I am doing wrong. You have me really curios.
If you want any more info, photos whatever I would be glad to upload for you.
Hi Keith;
I think that you have been told how to reverse the motor several times. The instructions were clear to those of us with motor experience but we seem to have forgotten that not everyone has our familiarity with motors.
You must reverse the starting winding.
Now, here's how to find the starting winding:
One end of the starting winding is connected to the start capacitor. Call this S1. Now disconnect S1 from the capacitor and use a continuity tester to find the other end. Disconnect and label the other leads one by one and check for continuity to S1. Be sure that you have continuity between S1 and only one other lead. Label the lead with continuity S2. Double check that there is continuity between S1 and S2 and NO OTHER LEADS. Interchange S1 and S2 and reconnect the capacitor (to S2 now). If there are no connection mistakes with the other leads the motor should now run backwards.
Bill
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"Why not the best?"
Jimmy Carter
Hi, New to this forum but spotted this thread whilst searching for way to reconnect a cropmton parkinson 3/4 hp motor. The motor was originally used to drive a table saw (which is what I am trying to use it for. I tried Bill's suggestion but unfortunately I have continuity betwee all terminals. The motor is working as wired and has a centrifugal switch (I can hear it operate) There are 5 terminals. Two at the top of the panel (both marked A)and three at the bottom. The power supply is connected across the two marked A (neutral to the left and live to the right) The capacitor which is in a pretty large metal can is connected between the right hand terminal (live input) and the extreme right hand termial of the bottom row of three terminals (it is marked Z or or possibly N sideways).
The left hand of the lower terminals does not appear to be connected to anything, the middle one which is marked S is connected to something in the bowels of the motor ! Any help would be appreciated as I cannot figure out which is what in order to reverse the starter coil.
Cheers
David M
Try to access the centrifugal switch. One end of the start winding goes to the centrifugal switch. You will probably have to disconnect the windings from the terminals.Find the other end of the winding that connects to the centrifugal switch. Reverse this winding.
Bill
--------------------
"Why not the best?"
Jimmy Carter
Older Brooks motors are usually reasonably well marked. I have a copy of 'The Little Red Book' which Brooks used to publish before they closed the UK factories. It's a marvellous reference if you can find a copy on ebay or Amazon.
Any chance of uploading a photo of the terminal box interior to the engineering.com filehost? The option is just below the box you'll type a reply in. I'll see how it matches up to the FHP motor diagrams in the book.
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