Need Help with Magnetic reversible Contactor

[Chris64]

I'm a little frightened of the wiries going to this thing. This is an Allen Bradley 705X-BOD (with 2x 1401-N10 surge supressors) that is currently controlling my 3-ph spindle motor. I'm pulling it out to put it in a new smaller case (and new controller), but I'm frightened of all the control wires coming to and fro on this thing.

Anyone know how these are wired or know where I might find a wiring diagram? The main 3 ph wires seem simple enough, especially since there are basically 3 wires in (top), and then 3 out (bottom, under a mystery device, maybe a breaker?)

Any info or thoughts on this would be helpful. I found some newer contactors on ebay for around $50 that I can get wiring on. This one seems to be going for closr to $300 in most cases...that might be because it's good, or maybe just old and hard to get (probably).

Thanks

[Al_The_Man]

Originally Posted by Chris64 = Anyone know how these are wired or know where I might find a wiring diagram? The main 3 ph wires seem simple enough, especially since there are basically 3 wires in (top), and then 3 out (bottom, under a mystery device, maybe a breaker?)

I guess the PDF I posted didn't do it
It is going to be wired up pretty much as the 3 phase reverser in the diagram.
Except it looks like you have 120v control voltage instead of 24v.
The control wiring is usually electrically interlocked through N.O. contacts on each side and also the N.C. motor over-loads (mystery device?).
If the wiring is in place, just reverse engineer it by tracing the wires and draw out the schematic.
Al.

[Al_The_Man]

Just an after thought on the PDF diagram, whatever type of contactor you use try and get one with a N.O & a N.C. auxiliary contact on each contactor or one that can accept add-ons, most modern ones do, they just clip on the front actuator with the new DIN style.
The reason is, especially with manual P.B.s, is that without using the N.C. contacts to interlock the two fwd/rev PB's, it is possible to energise the opposite coils, although the second one would not pick up due to the mechanical interlock, if you are using AC and the contactor is unable to pick up due to this mechanical Interlock, you will burn the coil out, this doesn't happen with DC coils, however.
The PDF I posted on the other link does not show this.
The N.O. contacts are shown in the normal way as latching contacts across the start PB's.
Al.

[Chris64]

Originally Posted by Al_The_Man I guess the PDF I posted didn't do it It is going to be wired up pretty much as the 3 phase reverser in the diagram. Except it looks like you have 120v control voltage instead of 24v. The control wiring is usually electrically interlocked through N.O. contacts on each side and also the N.C. motor over-loads (mystery device?). If the wiring is in place, just reverse engineer it by tracing the wires and draw out the schematic. Al.

Your PDF was a great help. I drew up a schematic of how this is all going to go together with your PDF as the model. Then I started looking at how things were going to come apart and got a little overwhelmed. This just had way more control connections then your diagram.

Like you said, I'll probably have to reverse engineer it a bit. I should just power it up while it's open (i've been a little intimidated to do that) and measure the voltage with different actions. Tricky with AC since I'm not sure what is "neutral."

So, in your opinion, use what I have or ebay? It must be an OK contactor for this size machine.

While we're on that topic. For my circuit I'll probably need a 110 line for something. My Dad is an electrician and suggested I go from L1 or L2 to Neutral (and yes, I'll be putting him to work on it when he's down for Christmas ). It appears that this existing controller went 220 to a 1:2 transformer to bring it back down. Thoughts? 220 would probably be less likely to be affected by spikes caused by the motor starting...but maybe not.

[HuFlungDung]

If you plan to go to a VFD someday (which is a practical necessity), you won't need that crap. You'll want to use the VFD to create the spindle motor control system. So don't waste more money buying yet more contactors. Those ones serve the same purpose as a brand new one.

For the VFD, all you will need is the mechanical disconnect to supply power to the VFD and anything else you might need to retain inside the cabinet. Estop and on, off, reverse must be handled within the VFD as you must not break the main power between the motor and the VFD output.

Each coil on the contactor relay has two contacts, an in and an out. Those will be interlocked through clever wiring methods so that both cannot engage simultaneously.

There is often an auxilary set of contacts there, which create a latched circuit after the coils have been momentarily energised by an external push button station (probably from the M function board, to a reed relay board, to an icecube relay to this contactor relay). So part of what the mess is, is the means of creating the latched condition of the coil so that current flows through an auxilary circuit after the pushbutton is released. Any interruption to that latched circuit (ie., spindle stop) breaks the current through the coil latched circuit causing it to drop out of contact when the springs open the contactor.

It can be tough to figure it out, I'll be the first to admit. But, if you're going to stick with contactors, you'll end up duplicating that 'mess' in your own way later on. You might even come to appreciate how well thought out it is

[Chris64]

I just relooked at it and I guess I'm throwing in the towel a little too quickly. I guess it just has 4 connection points per contactor (Like Al's PDF). The other connections are surge supressors and the overload thingamajig (it's already wired, don't mess with it, right?).

Hu, I totally understand what you're talking about with holding the contactor open...I'm guilty of making some low budget remote car starters with relay's using the same method. I guess I just wish I knew what did what so that I could be confident in my wiring. Al's PDF shows that one pair is a coil, and another is a capacitor (I think). I'm not sure if this is the same, and quite honestly I'm not sure why there would be a capacitor in there at all (I'm sure theres a good reason though).

With 12v I used to do a lot of bench playing with a makita battery...maybe I should do the same with this...just A LOT more carefully. (eek) After carefully documenting how this is connected that is.

[Al_The_Man]

Originally Posted by Chris64 So, in your opinion, use what I have or ebay? It must be an OK contactor for this size machine.

As long as it is rated for the correct HP, but like I mentioned, you should ensure you have, or can add, a N.O & a N.C. aux contact to each contactor.

Originally Posted by Chris64 My Dad is an electrician and suggested I go from L1 or L2 to Neutral (and yes, I'll be putting him to work on it when he's down for Christmas ).

You have the answer right there, 'My Dads an Electrician'
I would use the live and neutral for 120v rather than fitting a transformer.
I think you are confusing the N.O. contact symbol with a capacitor
Al.

[Chris64]

Originally Posted by Al_The_Man I think you are confusing the N.O. contact symbol with a capacitor Al.

oops!

the 220-110 transformer (it's in the pic on the left) I think might be dedicated to just controlling this contactor. Strange. Maybe it isolates the contactor from the rest of the circuit better this way.

[Chris64]

THAT MAKES SENSE NOW! You're right, I thought it was a cap (smaller then the other NO contacts)...I figured it cause some type of momentary surge so it wouldn't overwhel the coil or whatever, but with AC that was just not making sense...but basically just a little NO control circuit! Seriously, the light just went on here, thanks!

[Al_The_Man]

Incidentally, to avoid confusion, ladder or schematic diagrams usually show a N.O. like -||- and a cap like -|(- .
Al.

[Chris64]

Just a funny update. In my efforts to reverse engineer everything, I flip on my controller and presto, it works again (should I be glad?). Well I saw this as an opportunity to machine all the brackets I would need for the new encoders etc. So I grab my computer to start sending the new programs and...nothing. It was dead again.

That was it! I had enough! I photgraphed and documented everything and just started cutting components out. No during back now! ha ha ha. When I'm done I'm going to take this bandit case out to a field and go all "office space" on it! Well, not really, cause this thing would win...I'm really going to go "ebay" on all the little parts though.

What I was really surprised about was how small the power wires were that went to the driver transformer (Heavy BTW, maybe 50 pounds). Just two little (maybe 18 guage) wires and that's it. Then 4 big 10 guage wire coming out of it. Seems a little out of wack, since it was running at 110 and only converting it down to 80V. It's not like the the v/a draw is that different.

And it barely fits in my new case (whew). The contactor is next...but it's riveted in so I couldn't yank that out as easily.

Do you think I should worry about EMI from this transformer to the Gecko components? I found an EMI filter in there and figured I could probably reuse it.

[Chris64]

Also, just to update what the connections are in case anyone else runs across this type of contactor.

The two terminals next to the red writing are for the coil, ac 120 (as it states right on it - it seems so obvious in retrospect)
The two top terminals (labeled 5/7 on the left) are NC
The two terminals below those are NO.
The Surge supressor just gets wired parallel to the coil.

So each coil power is routed through the opposite contactor NC switch. This way they both can't be powered simultaneously.

I'm still not entirely clear on what the overload device at the very bottom is for (besides dealing with overloads). It has two small red wires fed to it for something. Thoughts?