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motor starting and reversing.

got cheap on ebay a box with forward reverse stop buttons, but that's all it is, the box and contactors under the buttons. The start buttons have push-to-make switches and the stop one has push-to-break.

So... can I make it drive the single-phase motor on the lathe, forward and reverse, and if so what else does it need. I already have stop-start-overload switch thing, but that only goes one way. It's also not no-volt release, which is not ideal.

currently, reversing is done with a pair of SPDT switches, which is far from ideal, especially as they're only just big enough current rating.

Reply to
Austin Shackles
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Use your existing stop start overload as the NVR and starter and wire the new box as a latching forward/reverse switch. Bob

Reply to
Bob Minchin

Strangely enough I was asked to produce a reversing controller for a type of tumbling machine very recently.

It has on and off push buttons and a three position switch for forward, off, and on. In the off position the start button does nothing but when set to forward or reverse then the on button starts the motor in the relevant direction and latches a NVR. If you reverse the direction switch while the motor is running the NVR drops out as the switch passes through the off position, stopping the motor, which you can start again by pressing the on button.

The NVR and fwd/off/rev switch only carry control currents.

Circuit diagram can be seen at:

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(File name is case sensitive)

Bob

Reply to
BobKellock

On or around Fri, 22 Aug 2008 16:51:38 -0700 (PDT), BobKellock enlightened us thusly:

The circuit I've just done would do that too, except that I happen to have the set of 3 buttons.

Reply to
Austin Shackles

d text -

Austin

I've tried to send you two diagrams for using your 3-button set-up. I hope I goy your e-mail address right.

Any questions, e-mail me direct. I can also supply a third diagram using relays instead of Contactor Aux contacts.

Regards Andy

Reply to
houstonceng

On or around Sat, 23 Aug 2008 08:29:15 -0700 (PDT), houstonceng enlightened us thusly:

yep, got 'em.

Reply to
Austin Shackles

Thats what Ive just done, exactly how you say

NVR will take 16 amps .

when the reversing switch is knocked between forward and reverse it goes through a middle region that knocks the main power off to the nvr through the bottom drum

why Austin is making it so complex i don't know.

All the best.markj

Reply to
mark

On or around Sat, 23 Aug 2008 12:50:18 -0700 (PDT), mark enlightened us thusly:

well, it's no fun otherwise. And I don't happen to have 2 4-pole contactors.

The circuit I'm messing with could very easily use an on-off-on changeover switch, but I happen to have a nice box with 2 green and one red buttons on it... The existing switch has overload but not NVR, and the existing reversing is done by 2 off SPDT switches which are not really up to the starting current, but were to hand at the time.

Reply to
Austin Shackles

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