Electrical motor wiring problem

[jplambs]

Hi all,

I am trying to wire a motor up at the moment with a forward and reverse function as well as a two way dead switch. I've got everything wired up ok at the moment but once I try to wire in the two starter wires I immediately loose the two way function, every time I turn the switch it only goes in the one direction. Any ideas? Thanks.

[rovercare]

More details? cct drawings? some single phase motors always spin in the same direction regardless of polarity

[jplambs]

The motor is capable of spinning in both directions depending on the polarity. It is from a wool press, the original motor died and the electrician brought out the new one, couldn't work out how to wire it and that was about 12 months ago. The system works so that once the press has corkscrewed down it hits the dead-switch which cuts the motor until the polarity is switched over. It does the same thing once it hits the top.

All of this is working without a hitch, until I tried to wire the starter coils in, I tried wiring them in so that they reverse polarity with the motor but that didn't work so I tried them normally and that didn't work either. The electrician took all the wiring diagrams with him so I don't have anything to work from as far as the motor goes.

[rovercare]

Starter coils? is it a 3 phase motor? with a simple forward/reverseing contactor setup? need more details, how many wires from the motor?, how is the limit in the control cct, hard without a visual

[Rangier Rover]

I had a single ph 480v motor that went both ways. Sent it away for a rewind. Put it back on and it went backwards:o
Wasn't good on a positive displacement mono pump:eek:

Hope my new hoist doesn't go backwards:lol2:

[jplambs]

Thanks rovercare, I'll take some photos in the morning and put them up, it has 4 wires coming out of the motor.

[rovercare]

Thanks rovercare, I'll take some photos in the morning and put them up, it has 4 wires coming out of the motor.


Is one of those wires connected to earth, the frame of the motor? is it 415V 3 phase? the more pics the better, what do you mean by starter coils? its hard to take someones terminology that isn't in the trade (even some of those in the trade:D) if you get me some detailed pics and PM your number I'll try walk you through it, if I get a chance tomorrow:)

[Blknight.aus]

I think hes refering to the starter coils as the ones that are wired up to the centrifuge switch on some single phase motors that dont have starting caps.

IF I remember correctly. on a Bi directional motor that has that setup you leave the swtiching coils wired up as per normal and its just the pole change that does the DOR change.

[jplambs]

The first few pics.

[jplambs]

The next lot, please try not to laugh at my wiring diagramme.

[scarry]

Being a Fasco 240v motor,i would get onto your nearest Fasco agent & they will be able to Fax/email you exactly how it should be wired.

Remember also if your not qualified to do electrical work,they may not be too helpful....
Any electrician who has the info from Fasco about the motor should be able to sort it out reasonably easily

[jplambs]

Ok, when I said four wires yesterday I forgot to include the earth wire, sorry about that.

The black wire goes to the trip switch before dissapearing into the motor and the red/brown wire goes directly into the motor. The lilac and white wires are the one that run into the starter components and are the two wires that I currently do not have connected.

The wiring diagramme is how I currently have it set up so that I can swap polarity while still maintaining the pressure kill switch for the press. Thanks again for your help.

[jplambs]

Hi Scarry,

I'll give fasco a try pending what anyone else comes up with. The reason I'm trying to sort it out as I mentioned before is that the electrician couldn't work out how to do it and he had the wiring diagramme.

[jplambs]

Ok, I now have a proper wiring diagram of the motor, the original photo's of the motor are now void as I have undone the wiring mods that the electrician did and have rewired it as it originally was. Everything is now working fine.

Now the question I have is how do I wire up an external switch to reverse the polarity? I can change the wires over internally as the diagramme suggests and that swaps the direction of the rotation but how do I do so externally? Or is this motor not suitable for that?

[Vern]

double pole three position change over switch?

[jplambs]

I think that, that is what I am using but even though I can change the positive and negative over it doesn't make any difference to the direction of rotation.

[Mick_Marsh]

I think that, that is what I am using but even though I can change the positive and negative over it doesn't make any difference to the direction of rotation.
No, it wouldn't. I'm a bit hazy on this. I usually deal with three phase motors. I'll consult my old circuits to confirm but I think you have to only swap the field wiring.
I'll see if I can find a single phase reversing starter circuit for you.

[2stroke]

You need to swap the red and black wires only not orange and blue. If you swap both it will go the same way.

[Vern]

I think that, that is what I am using but even though I can change the positive and negative over it doesn't make any difference to the direction of rotation.
As mick said, pretty sure you'd have to change the field wiring. Don't see much of this around, reverse rotation on single phase motors, mainly always 3 phase. I should have said, can you change the field wiring with a three position switch.

[Mick_Marsh]

There you are, a man who knows his stuff.
Don't forget to use a three position switch with a centre off position.

[rovercare]

You need to swap the red and black wires only not orange and blue. If you swap both it will go the same way.

That:)

To change direction, change over the terminals of one of the windings.

Its all to do with the capacitor and how it starts out of phase which changes direction, far to complicated, 3 phase is betterer:D

[jplambs]

Sorry for sounding stupid but what do you mean by field wiring? The current switch that I have it hooked up to is a three way switch with a centre off position.

[Mick_Marsh]

Sorry for sounding stupid but what do you mean by field wiring? The current switch that I have it hooked up to is a three way switch with a centre off position.
Sorry, I meant winding. Main WDG on your circuit.

Found this:

To reverse rotation of a single phase motor,interchange connection of the starting winding. The starting winding is one with a terminal connected to a start capacitor.Disconnect the other end that normally is connected to the running winding or common.Transfer connection of this terminal to the capacitor and the original terminal connected to the capacitor connect to the common winding

[Mick_Marsh]

I'll find a confirmed circuit.

Found this as well:

Capacitor start motor
https://www.aulro.com/afvb/images/imported/2010/08/1347.jpg (http://en.wikipedia.org/wiki/File:Condensatormotor.svg) https://www.aulro.com/afvb/ (http://en.wikipedia.org/wiki/File:Condensatormotor.svg)
Schematic of a capacitor start motor.


A capacitor start motor is a split-phase induction motor with a starting capacitor inserted in series with the startup winding, creating an LC circuit which is capable of a much greater phase shift (and so, a much greater starting torque). The capacitor naturally adds expense to such motors.
[edit (http://en.wikipedia.org/w/index.php'title=AC_motor&action=edit&section=9)] Resistance start motor

A resistance start motor is a split-phase induction motor with a starter inserted in series with the startup winding, creating capacitance. This added starter provides assistance in the starting and initial direction of rotation.
[edit (http://en.wikipedia.org/w/index.php'title=AC_motor&action=edit&section=10)] Permanent-split capacitor motor

Another variation is the permanent-split capacitor (PSC) motor (also known as a capacitor start and run motor).[6] (http://en.wikipedia.org/wiki/AC_motor#cite_note-TMotors-5) This motor operates similarly to the capacitor-start motor described above, but there is no centrifugal starting switch,[6] (http://en.wikipedia.org/wiki/AC_motor#cite_note-TMotors-5) and what correspond to the start windings (second windings) are permanently connected to the power source (through a capacitor), along with the run windings.[6] (http://en.wikipedia.org/wiki/AC_motor#cite_note-TMotors-5) PSC motors are frequently used in air handlers, blowers, and fans (including ceiling fans) and other cases where a variable speed is desired.
A capacitor ranging from 3 to 25 microfarads is connected in series with the "start" windings and remains in the circuit during the run cycle.[6] (http://en.wikipedia.org/wiki/AC_motor#cite_note-TMotors-5) The "start" windings and run windings are identical in this motor,[6] (http://en.wikipedia.org/wiki/AC_motor#cite_note-TMotors-5) and reverse motion can be achieved by reversing the wiring of the 2 windings,[6] (http://en.wikipedia.org/wiki/AC_motor#cite_note-TMotors-5) with the capacitor connected to the other windings as "start" windings. By changing taps on the running winding but keeping the load constant, the motor can be made to run at different speeds. Also, provided all 6 winding connections are available separately, a 3 phase motor can be converted to a capacitor start and run motor by commoning two of the windings and connecting the third via a capacitor to act as a start winding.

[2stroke]

You just swap the red and black wires as it says on the drawing. Oh and there isn't any "field winding" just a start and a run winding.
Edit, just looked at the drawing properly, it's a cap start-run motor, so both windings are in circuit in run (after the centrifugal switch open circuits the start cap) so technically there's a main and an auxiliary winding.