No Sweep Reverse

[8270tom]

I have a stator that works fine, but has no sweep reverse. According to the schematic the sweep reverse switch reverses the wiring to run the sweep backwards. Please explain why this one stator doesn't run backwards.

[triac]

Re: No Sweep Reverse

8270tom, Just a few questions.

What happens when you try to reverse the sweep? Nothing or does it hum and eventually trip the KX?

Are you sure it’s the stator?
If answer is no…Put on another machine to see if problem follows.
If problem follows then it is the stator.
If problem stays with the machine then you could have bad wiring going to motor plug, bad chassis, or reverse switch (or connection) is bad.

Are you running a solid state start switch on this motor?
If yes then what kind?
If it’s a Quality SSSS (or similar type) then you need to follow the directions to modify the wiring inside the wireway.
The AMF (orange round canister) does not need any wire modifications.

Triac

[maister]

Re: No Sweep Reverse

stator does not control sweep reverse.Perhaps the motor is running backwards, although you would not get it stopping at first guard. I suspect wiring in plug is suspect.

[triac]

Re: No Sweep Reverse

Originally posted by maister:
stator does not control sweep reverse.

<font size="2" face="Verdana, Helvetica, sans-serif">You are correct the stator does not control the sweep reverse. But a SSSS that needs to have wiring modifications will affect the output to the motor. This is one reason I need 8270tom to answer some questions before I can offer any advice. For example…if he’s running the stock centrifugal mechanism, then I would suggest that the problem is on the machine side.

However, if he is running the type of SSSS that needs rewired on the machine and it is not modified, it will hum and pop the KX. The reason wire modifications are necessary to some SSSS and not others are their internal design and how they are hooked up to the motor. These particular SSSS will not allow the phase to be reversed to the offset start windings in relation to the source voltage without wiring modification.

Triac

[8270tom]

Re: No Sweep Reverse

Contacted AMF, seems they've had problem like this before and it requires a rewinding. Will just use it on table motor. Problem only occured with this stator.

[Andrew]

Re: No Sweep Reverse

Did you tell AMF anymore info than you mentioned here?

I'm a bit skeptical about you needing a rewind to fix this. If the motor runs one way reliably, then the windings sound fine to me.

Have you actually tried changing the stator with another motor?

The SSSS problem is certainly a likely candidate if you have those types of SSSS.

But another simple problem may be a faulty sweep reverse switch.

[wb8yjf]

Re: No Sweep Reverse

The M2 relay can cause sweep reverse problems too..

[30n70]

Re: No Sweep Reverse

It is possible to have an open (reverse) start winding. Put a meter on it

[maister]

Re: No Sweep Reverse

Excellent post Triac.
Maister.

[Alastair]

Re: No Sweep Reverse

Used this topic to help me re-gain sweep reverse after an offspot on a particular lane which was having none of it what so ever.

Things checked for, wiring from switch, Continuity of wires, replaced switch, swopped chassis, checked c1 pin, checked motor plug, but all to no avial.

It ended up the fault lay inside the stator.
The wiring of the board inside was such that it WOULD allow the motor to run in a forward direction but not in a reverse direction. Three of the wires coming from the plug to the board were in the wrong places.
When I wired it up the same as a good working Westinghouse combo, the motor ran backward, so all i did was reverse the start winding wires around and Voila, the motor now runs backward and forward.

Very strange, as I would have just expected the motor to either run or not run at all!!

[Andrew]

Re: No Sweep Reverse

I wonder if that's what happened with 808Tom's stator.

Andrew.

[Mike Stalker]

Re: No Sweep Reverse

Triac and Maister: what are you guys talking about.

The stator does not control the sweep reverse but it has to electrically perform the sweep reverse.

If my motors loose the reverse winding I mark them and move them to the table before I get them rewired. 808tom you can do this too if you need the stator.

[triac]

Re: No Sweep Reverse

The reverse winding and the start winding are one in the same. The start winding is only used to give the motor a push start in the desired direction. The direction is determined by the difference in the position (angle) of the sine wave input to the start and main windings in relation to the source voltage. So what you have, is a single phase coming in, but in theory you have two phases starting the motor.

In layman’s terms (although not 100% correct, its more complicated that that [img]/content/btubb/images/%%GRAEMLIN_URL%%/wink.gif[/img] ), basically one winding is pushing and the other is pulling. By reversing the phase on the start winding (only), you have reversed the push pull to pull push.

The only way you can lose the reverse function only in the motor, would be because of a problem with the input to the start windings in relation to the mains, such as what Alastair found or by not correcting the direction of the phase in the Quality type SS.

Triac

[Andrew]

Re: No Sweep Reverse

Mike,

Are you being semantic about the word "control"?

If you like, no, the stator does not "control" - it just "does".

The stator contains both run and start windings. The start winding determines the start direction, relative to the run windings. Usually, external circuitry determines which is which. Hence the "control".

There are cases where that's not possible (some National backend motors cannot be reversed because the start winding is connected to the run winding within the insulated wiring).

I'm still at a loss as to how a running and reversable sweep motor could lose its reverse ability but retain its forward ability (in and of itself). Unless it's a facet of the SSSS (and all bets are off until Ray says otherwise :-)), I find it VERY strange.

Andrew.

[Alastair]

Re: No Sweep Reverse

Maister and Triac are perfectly correct in there postings as usual.

Surely if the start winding is gone, then the motor would not run at all? It would just hum. As the winding is crucial to the cyclic phase induced, inturn leading to directionality of the motors output .
(a full explination of this would be nice, please)

No ssss switches used on this boy, as cant get them to work on the sweeps. Yet, anyway.