motor starting and reversing.

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

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:

Bob

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.

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

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

yep, got 'em.

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

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.