# Yet another 1ph 220v reversible motor and switch wiring issue



## tjm_ar (Jun 3, 2020)

I'll dispense with the background issues (unless you really want to hear the story) and post my wiring diagram both for checking and for a better way to do it.  There's so many switch types and incomplete switch and motor information that it's difficult to reach a solid conclusion for a wiring setup.  That leaves us with connections that are probably better than a best guess but maybe not quite the perfect setup.  A final setup that runs and doesn't produce smoke is probably OK, but?  I really don't see any other way to make the start winding run on 110v and still retain the reversibility.  My diagram is there along with a blank worksheet if anyone has either a correction or a better/easier way to do it.  My diagram uses 5 wires from the motor to the switch.  I've seen diagrams with 3 and 4 wires to do the same thing but I suspect it has to do with the type of motor and windings.  I'm far from being a motor expert so if you happen to use my wiring methods then you're on your own.  Pics and pdf included.  For info, Grizzly G6760, alias X6320A, Jet 836, Enco 10-1525.

Thanks for taking a look


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## Bi11Hudson (Jun 3, 2020)

When dealing with 120/240 volt motors, the *usual* practice is to place the two *run* windings in parallel(120v) or in series(240v). For 240 volt connections, the *start* winding will be connected at the "center tap", the common connection for the *run* winding. For 120v connection, the *start* winding is connected in direct parallel with the *run* windings. Reversing the two *start* winding connections will reverse the direction of rotation.

Looking at the connection diagram alone is meaningless to _me_ right now. I have to study that diagram with the motor to make good sense of the overall connections. It does look to be a usual dual voltage reversible motor. It's *my mind* that is in left field.

The primary question here is whether you are connecting for 120 or 240 volt supply. For 120 volt supply, wiring in the reversing switch will be to the diagram for whatever switch you are using. For 240 volt connection, there are 2 live wires feeding the motor, but only one line contact. Meaning that with the usual reversing switch with one line contact, the other will be connected without a switch. Live all the time. That would require a two pole switch somewhere to be perfectly safe.

In my case, I don't have one. And don't worry about it. But I've been an industrial electrician for over 50 years  and am very particular about grounds and other electrical safety.

.


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## tjm_ar (Jun 3, 2020)

Thanks for the reply.  I'm working with the higher voltage wiring only, 208-240v.  Mine is actually 240v.

Both lines are disconnected from the motor in the OFF position, and both lines are connected when switched to either the Forward or Reverse position.  No power makes it past the switch in the OFF position.  The colorful diagram and the numbered switch connections with the small F or R in the block show which switch terminals are hot in the Forward or Reverse position.

This is my backup motor and I'm waiting for a new LW5-16 switch to actually make all the connections and give it a try.

My installed and working motor is a replacement that has the Euro/Chinese terminal labeling and config, if anyone can figure out what that means on any particular labeling day.  I stuck with the label on the motor and configured the switch accordingly.  It works in forward and reverse using only three wires from the motor to the switch.  I'll post that connection diagram if for nothing else but to add to my own confusion.   Your confusion factor may vary.  I have no idea which wires go to which coils/capacitors and I don't plan on disassembling a working configuration to find out unless I develop a serious brain malfunction.  There's probably a U-V-W-Z configuration diagram somewhere that matches this motor but I haven't found it yet.  It works with three wires, but I can't explain it.  Use the switch legend from the first post pic.


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## Ulma Doctor (Jun 3, 2020)

here is the stock wiring diagram for my shenwai sw900b 1236 lathe, (it has been changed to VFD and a marathon 2hp motor since)
the lathe was capable of running 220 or 115v with the change of a couple jumper wires at the control transformer
it has a 4 wire momentary switch control system


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## markba633csi (Jun 3, 2020)

On 230 volts you should only need 3 wires from motor to switch- let me cogitate on your diagrams and I'll post a sketch for you
-Mark


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## tjm_ar (Jun 3, 2020)

markba633csi said:


> On 230 volts you should only need 3 wires from motor to switch- let me cogitate on your diagrams and I'll post a sketch for you
> -Mark



THAT'S what I'm looking for.  Feel free to print and use my switch and motor template if you like, but I'm not seeing any other way to run the start coil at 120v.  This is a single phase motor.

Thanks,
Tony


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## markba633csi (Jun 4, 2020)

Hi Tony- this should work
I suspect your red/green switch table was incorrect, I pulled one off the web; you should check that your switch matches it using a continuity tester or ohmmeter.  If your switch really is as you posted I will need to modify this sketch- let me know
-Mark


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## markba633csi (Jun 4, 2020)

Tony: If your switch is really as you posted then you would connect it like this:  (1,2,3,4 not used)


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## tjm_ar (Jun 4, 2020)

Thanks, was just in the process of figuring out how this actually connects for both switches.  In effect, we're only changing which line gets connected to T8, but I'll admit I'm unclear about how or why that works.  The other motor I already have running correctly with the LW5-16 and only three wires had a diagram on the plate that I was hesitant to use but it actually works perfectly.  It's labelled in the Chinese/Euro format, the connections are made internally and there's no labeling on each wire.  That pic is up there in my second post.

Anyway, my switch contacts are correct and verified with an ohmmeter.  No problem.  My switch is a LW5-16 and the one you have posted is an LW28.  There seems to be an endless number of configurations for all of the LW series drum switches that I've found.   I already have a new LW5 on the way and I'll check it's configuration to make sure it's the same, too.  I can use either and I don't mind getting the LW28 as it appears to have a higher amperage rating.

My new switch won't be here for a few days but I'll post the results with schematic and pics when it's done.  I'm sure that this thread should clear up a lot of other wiring diagram posts for drum switches and reversibility.

Thanks for the assist.

Tony


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## markba633csi (Jun 4, 2020)

You're right about the endless number of different switches, there also seems to be an endless number of people confused by how to wire them 
-M
ps in this 3 wire configuration moving T8 from one line wire to the other gives the reversing function, and the start leg only sees 120 volts since it connects to the midpoint of the two run windings
pss you can swap T8 and T5 if the motor rotation is backwards from the switch handle


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## tjm_ar (Jun 4, 2020)

markba633csi said:


> You're right about the endless number of different switches, there also seems to be an endless number of people confused by how to wire them
> -M
> ps in this 3 wire configuration moving T8 from one line wire to the other gives the reversing function, and the start leg only sees 120 volts since it connects to the midpoint of the two run windings
> pss you can swap T8 and T5 if the motor rotation is backwards from the switch handle



Yup, that's me.  Just throw in a Chinese equipment manual to help.

Figured about the T5-T8 swap.  Somewhere in this stack of hand-drawn schematics piled up on the floor I have/had one that looked something like that, but not quite.  I ran that one by the local electric motor guy who said it wouldn't work-'you need the five wires'.  My drawing wasn't clear and he was busy so I didn't pursue it.  

What year 633?


Tony


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## markba633csi (Jun 4, 2020)

Oh, I don't have the 633 anymore- it was an 84' which I paid too much for and it was burning oil so I donated it
I do have a 68' Alfa duetto (Graduate car) that looks a bit ratty but runs pretty good
-M
ps he was probably thinking about the reversing 120 volt case, for that you really need 4 wires + ground so 5 total
be sure to provide a ground on yours so 4 total


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## tjm_ar (Jun 5, 2020)

markba633csi said:


> Oh, I don't have the 633 anymore- it was an 84' which I paid too much for and it was burning oil so I donated it
> I do have a 68' Alfa duetto (Graduate car) that looks a bit ratty but runs pretty good
> -M
> ....



The Alfa is not easy to come by these days, either.  Just found out today that Dinan opened again in Mountain View.


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## tjm_ar (Jun 6, 2020)

Received the new LW5-16 switch yesterday and the configuration is the same as the LW28-32/3 switch that markba633csi provided in his diagram.
My original LW5-16/3 switch is either some other model number or version OR it's a switch Grizzly ordered with a special configuration, which I think is most likely.  I'll wire this one up this morning and provide the results.

(added at 11:46am)
Done, and working very nicely.
Thanks, markba633csi, good work.  Pick a local pizza joint and and PM me the details and I'll have a pizza sent tonight.

(added 1:35pm)
Oops.  Maybe not.  Starts and runs fine on the first try, after the first try motor seems to turn slower with a strong vibration and gets warmer to the touch than it should.  Investigating.

tjm


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## markba633csi (Jun 7, 2020)

I'm thinking maybe bad capacitor(s)- how old is this motor?
-M
edit: OOps I missed the fact that the motor is not the one in post #1-  that changes things- let me take another look
OK I edited the sketch to add the U,V, and Z nomenclature:  (my concern about the capacitors still applies though)


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## tjm_ar (Jun 7, 2020)

Sorry, but let me clear this up.  I have two motors, both brand new out of the box.  The motor with the U-V-Z labeling came from Grizzly at a high price and although 'NEW' it looks like it might have been in that box for 20 years but works perfectly fine, so far.  The other new motor, to be used as a backup, has the vibration issue and I'm thinking either a cap or the centrifugal switch isn't working properly or consistently.  Before I get into taking it apart to finding the problem I'll check first with the supplier tomorrow morning and provide the results.  I'll keep the T-nums to UVW diagram for future reference, though, and I'm sure it'll come in handy.

Thanks,
Tony


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## tjm_ar (Jun 12, 2020)

Update:

Motor supplier requested a video of the unusual vibratory action of the motor and so I powered it up to verify the problem, which still existed, but after the camera gear was setup it no longer would go into the vibration mode.  I've been trying it for a couple days and can no longer get that odd vibration response.  I'll just leave it alone for now but I think the most likely suspect for an intermittent issue would be maybe a sticky centrifugal switch that didn't cut power to the start winding and after numerous starts in both directions it loosened up.  Maybe this is a  bad diagnosis but the only other thing would be a intermittent capacitor but I'm thinking once they go bad they're done so I'll rule that out for now.  As of right now, everything works as planned.


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## markba633csi (Jun 12, 2020)

LOL darn intermittents!


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## tjm_ar (Jun 12, 2020)

markba633csi said:


> LOL darn intermittents!



Intermittent, but found the problem.

Not the centrifugal portion of the switch, which I thought wasn't operating, but the switch contacts themselves were stuck together and didn't take the starter cap out of the circuit so it actually stayed engaged.  When this happens the starter cap circuit remains energized and I suspect it causes a field phasing issue that caused the vibration.  Now the question is 'why'.  Were the contact points too rough and sticky OR is the starter cap going bad and causing too much current though those small contacts?  I polished the contacts so we'll see if that helps.

I gotta say, I've learned more about AC induction motors, with help, since my mill motor went bad than I thought possible.

Tony


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## markba633csi (Jun 12, 2020)

Could be a variety of reasons or combination of them.  It's possible a failing capacitor is at least partially responsible- or poor quality contact alloy? 
You just got your motor diploma, wear it proudly


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## tjm_ar (Jun 12, 2020)

markba633csi said:


> Could be a variety of reasons or combination of them.  It's possible a failing capacitor is at least partially responsible- or poor quality contact alloy?
> You just got your motor diploma, wear it proudly



The contact points are kind-of small but they are solid copper.  If the issue continues then I'll find a better set of contacts (they're cheap) and I'll check the cap.   I might do both anyway if I get time.  It appears to be a well built motor but it is a Chinese manufacture.  After the start cap releases there is about 8 amps through the start winding, which seems to be about right running at 120v.  Not much of a jump in start up amps that I can see with my equipment for that circuit.  Running amps is right where the label says it should be.

Tony


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## markba633csi (Jun 12, 2020)

Solid copper probably was chosen because it's cheap and available- most domestic high current switch and relay contacts I've seen are a silvery alloy with some rhodium or other hard metal that resists sticking


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## tjm_ar (Jun 26, 2020)

Update:  In the process of trying to get one of these rotary/drum 'FWD-OFF-REV' switches with the config shown in post #8 I ordered a LW5-16 switch from Amazon hoping to get the same switch.  No luck, but also no big deal.  The switch I received operated a bit differently than the original but exactly like the LW28-32 that markba633csi came up with in post #7.  Just needed some jumpers to work.  But, although these switches work fine, after taking one apart to try and reconfigure it's operation it doesn't appear these are quality switches.  I found Kraus-Naimer switches, downloaded their catalog, and with the help of their experts, found a switch with better specs, smaller, with nice features and almost made to order.  I should have that today.  I got to pick the switch size, amperage, front panel and labeling and knob type and color.  Not cheap but safer than the $12 China made units, I think.
I'll post more updates for installation and operation over the week's end just in case there is interest.

tjm


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## tjm_ar (Jul 15, 2020)

Here are the Kraus&Naimer switches I found compared with the usual LW series switches found online.  First,  the A712 and WAA612 diagrams below are from the Kraus&Naimer wiring pocketbook ( https://www.krausnaimer.com/us_en/catalogs ).  The A712 is the config you usually find as replacement switches and need to be jumpered to work.  I grayed out the 4th pole.  The WAA622 config is made for single phase, reversible motor wiring with both external and internal jumpers.  Both configs work, just a matter of how neat you want the operation to be.  I now have two of the Kraus&Naimer WAA622 configs for my motors.  The diagrams and differences are also shown below.  The Kraus&Naimer switch is about half the size of the LW5 with slightly more amperage capability, has a neater setup, terminals are recessed to avoid shock, you can choose the faceplate and handle config and the switch body detaches from the mount for easier access.  I'll post the before and after switch installation in the switchbox later today.


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## markba633csi (Jul 15, 2020)

Diagrams a bit confusing- must be euro made


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## tjm_ar (Jul 15, 2020)

markba633csi said:


> Diagrams a bit confusing- must be euro made



Having now dealt with this stuff and trying my own diagrams, I actually find these KN diagrams more usable as they have the position/connection chart AND the internal switch layout.  It also helps to have the switch in hand.  Following the current flow through these diagrams just seems to be less confusing than my own drawings. Combined with your schematics this has become easy work.

tjm


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## tjm_ar (Jul 15, 2020)




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