2 speed Single phase motor connection
Anyone familiar with 120VAC 2 speed (3600/1800) Motor connection? I'm trying to help someone get running a small lathe that has a 2 speed 120vac motor. The wiring diagram in the manual shows what looks like 4 coils, connected in 2 series pairs. The pair that I assume is the motor winding has a connection to the common labeled "Z" the other ends of the 2 coils in series are labeled "X1" and "V1" The other 2 coils in series is labeled "U" at the common the other ends "X2" and "V2". A capacitor is connected to "U" and nothing else. There is NO centrifugal switch that I know of! At least I'm told that no click can be heard as the motor slows to a stop. 2 switches provide Forward and Reverse depending on which is depressed, Stop resets at switches therefore Forward and Reverse switch act as On/Off too and remove all power when Up. A third larger button operates two switches for High and Low and is returned to Low when the Stop button is pushed. For High Speed operation both a directional button and large button must be pushed to lock the button down in High Speed.
The schematic is poor in that it does not show the internal connections of the switch so I have to guess at the operation. From what I'm guessing there is no phase reversal to "Z", "X1" and "V1" However "Z" and "X1" "V1" are always opposite phase but not phase switched. "X2" and "V2" reverse phase for Forward and reverse along with the connection to the other side of the Capacitor and I assume that is the start/run winding.
Checking the switch proves out the connection assumption however the Capacitor does not get connected in Forward. Possibly a missing jumper or short damaged contacts. The motor will run fine in Low Speed Reverse and seem to start and run fine in Low Speed Forward though the Cap has no connection. Problems occur in High speed.
Making a four 5watt lamp test circuit to simulate power applied to the coils with the motor disconnected from the switch. Lights lit as the should have in Low and as expected in High with no connection to "U" since the Capacitor was also removed!
To check phase reversal I disconnected "X1" and "V1" and attached them to "X2" and "V2" so that if there was a phase reversal on one the other will go out. Low Speed again responded as expected Reverse lit the lights as they should have and Forward because of the failure to connect to "C" a path was created thru 3 bulbs"X1", "X2" and "V2". However in High and especially Forward things changed. 'X1" lit as it should have and this time "X2", "V2" and "V1" should have been in series. However "X2" was about 1/2 but "V2" was almost full brilliance while "V1" was out indicating there was some path thru the low speed switch!
Each time I made a test, I got more questions than answers! OK, throw caution to the wind, wire the motor direct to the line. One phase connected to "Z" and to the Capacitor. Other phase connected to "X1" and "X2", motor ran low speed Forward, reversing Capacitor and "X2" motor ran Low speed Reverse.No connection to 'V1" or "V2" both insulated and not connected to each other. OK! Now connected "V1" and "V2" as above for High Speed "X1" and "X2" disconnected and insulated. Again all speeds the same, LOW.
Name plate Give Type as TTL, All I can find for TTL is a Motor Company in Taiwan. They do not list this type of motor. Anyone know How this motor can be wired to get High and Low speed? If I know how to wire it I can get the switch to work or modify it to get the intended operation! This is a 2 and 4 pole motor, I'm thinking I should get High speed when connected as I did. Any Ideas????
Single Phase Condewser (spelled this way) Run Type
Stanley Electric Works Co. Ltd.
A motor with a capacitor and no switch sounds like a "PSC" motor..... not usual for a machine tool , but not impossible.
I VERY MUCH SUSPECT, having had experience with this before, that the motor CANNOT BE STARTED in one of the speeds.
We have a client with an HVAC blower setup in their product that works like that....
The motor is started as a PSC, with the cap connected to one of two identical windings to determine direction. I want to say that is the HIGH speed.... because it has fewer poles.
Once started in high speed, the capacitor is disconnected, and the windings are re-connected in the proper phase to double the number of effective poles. The motor then operated as a "normal" induction motor of that many poles.
Your friend's motor SHOULD have some sort of diagram. I can, in a few days, find a copy of the client's setup..... Can't let you see it, but I can likely copy it with all ID eliminated, or at worst, re-draw it. There is no special IP involved, just client confidentiality.
I have no idea if that will help, because your friend's motor is going to be different. but it may let you see what is probably happening. You should be able to see what the contactor is probably doing, and see if it does..... and know what to try reversing to make it "go".
If you were charging for your work, a replacement motor could have been cheaper, before lunch.
Originally Posted by Froneck
Your a generous person, but that motor is from some Taiwan company, NOT The Stanley Works.
STANLEY ELECTRIC WORKS CO., LTD.
The motor data was taken directly off the motor. I didn't see it but told that it was on the motor.
There is no way do disconnect the cap, the common side of what looks like dual start windings is wired directly to the capacitor.
The motor was running on low speed forward and reverse. Pushing the button to get into high started the motor but at a slower speed until smoke was detected.
The two Identical windings don't seem to be for direction, That's done by reversing the phases connected to the start winding only the motor winding is not reversed. What's crazy is that the switching looks like what's required for a 2 speed 2 winding motor. He sent me the manual but there's no mention how to start the motor or anything about switch sequence.
It's getting confusing...........
There must be switching to reverse, AND switching to change speeds.......................... The speed change must rearrange the windings. How many wires are there?
I thought you said the cap was not connected in one setting at least.........
The way the switches are set up is Forward and Reverse both have 4 contact pairs. One pair is jumped to the other "Z" is connected to one jumped contact and power to the other so that if either button is pushed it will put power on "Z" from the same phase. Another has only one jumper and connected to the non motor side of the capacitor, the other contacts are connected to the 2 phases so depending on which switch is pushed determines which phase the capacitor is connected to.
The other 2 pair on the switch are done the same way! However the output is attached to another 2 switches controlled by one button. Up is low Speed, Pushed down is High speed. (That's an assumed speed since the initial problem was that the motor would not go into High but worked fine in Switch Up running at low speed) Those 2 switches have 2 pair of contacts each and the inputs are jumpered so which ever switch is pushed the output is identical. One contact pair on each switch is connected to the output of the non phase reversing phase pair and the other to the phase reversing pair of the Forward/Revers switches. Selecting High Or Low speed have the same output from the two respective switches. Input power is connected to "S" and "R" Therefore:
(A) Low speed Reverse: "R" connected to "Z" thru Reverse switch, "S" connected to "Cap" thru Reverse switch, "R" connected to "X2"
thru Reverse and Low speed switch, "S" connected to "X1" thru Reverse and Low speed switch.
(B) Low speed Forward: "R" connected to "Z" thru Forward switch. "R" connected to "Cap" thru Forward switch, "S" connected to "X2"
thru Forward and Low speed switch, "S" connected to "X1" thru Forward and Low speed switch.
(C) High speed Reverse "R" connected to "Z" thru Reverse switch, "S" connected to "Cap" thru reverse switch, "R" connected to "V2"
thru Reverse and High speed switch, "S" connected to "V1" thru Forward and High speed switch.
(D) High speed Forward "R" connected to "Z" thru Forward switch, "R" connected to "Cap" thru Forward switch, "S" connected to "V2"
thru Forward and High speed switch, "S" connected to "V1" thru Forward and High speed switch.
Connection above assumes "C" is supposed to be connected to "R" in Forward however there is no connection, motor will run in Low Forward. I was told that during a jam the motor stalled then reversed itself with no manual action.
There are 2 switch assemblies one installed in the lathe, another spare that may have been replaced. Jumper wires are the same and comply with the schematic. Wiring on "Spare" switch looks more professional than the installed switch. Both switches are wired so that "R" is connected to the "cap" in Forward but for some reason no connection is made by the Forward switch installed in the machine. However connection is made in the spare. The above switching arrangement is as per the schematic but no contacts are shown on the stupid schematic. Continuity testing confirms operation of the switches. Problem with the spare is that it will not lock in when the speed selection is pushed.
Motor is shown as "V1"---coil---"Z"---coil----"X1"
6 wires from the motor "X1", "X2", "V1","V2", "W" and "Z" "W" is shown on the schematic to be directly connected to the capacitor. no other connection is shown for "W"
"W" and "Z" are common to both coils and can't be disconnected, no connection or continuity between "W" or "Z"
The general idea makes some sense..... there are two windings per section, one being the 2 pole (high speed), one being the 4 pole (slow speed).
The main winding stays the same any way you work it (but is selected for whichever speed). The other winding is reversed for forward and reverse, no matter if it is high or low speed.
However, the connection that doesn't connect to the capacitor is likely wrong..... something will need to connect there at any speed.
Are you sure there is no centrifugal switch? and no timed switch?
Yes I too thought it was a 2 winding motor. The guy told he knows the sound of the Capacitor centrifugal switch but the sound is not made by this motor. However it's possible it's some type of silent switch or one that makes very little noise.
I had him check the switched connection to the Cap. of Forward a few times, every time I was told it was not connected. Yet the "Spare" switch does connect! I had him make a 5 watt lamp circuit equal to the motor winding using the bulbs instead of coils. Connect power to the system. Again the test showed no connection to the capacitor in Forward! I thought that maybe the low voltage on the digital meter was too low to break over any contact resistance. But The bulb did not light in Forward, Reverse worked as it should have!
I know what your saying but it seems to start in low speed without Cap connected in Forward. I did try putting the bulb in series with the cap but the motor would not start. Which makes no sense! I asked him to repeatedly push forward on and off while the lights were connected to see if there might have been a momentary connection to give the motor a kick. Nothing he did could get a flicker in Forward. I thought with a bulb in series with the cap. I could see if there was some sort of centrifugal switch. I might try putting multiple lights parallel in series so that there is enough to get the motor to start and see if there is a switch. There is no resister across the cap. so if I ask him to put that digital meter on the cap it might take a while for it to discharge if there is a switch. Like I said every test I had him make only created more questions! Then I told him to wire the motor Direct in the connections assumed the switch was making. Motor ran at the same speed 1800RPM in all 4 tests. Motor direction changed Forward and Reverse but was the same direction for both High and low speeds in other words Low speed Reverse and High speed Reverse when in the same direction at Low speed. High Speed Forward and Low speed Forward also ran in the same direction but opposite the rotation of Reverse but also at Low speed!
We had a couple of small 8.6 Emcos at work for little jobs. I recall that you pushed the forward or reverse button for starting and low speed. Once running if you needed fast you pressed a high speed button. This sounds like what you have. Here's a link to a schematic: Emco V 10 P and Mentor 10
I wish I could remember which button on the schematic did what.
You don't have to switch out the cap. If you leave it in, you'll modify the torque-RPM characteristics of the motor. It'll likely be smaller than a start only cap & I'll bet there'll be less starting (low speed) torque but there will be more running (high speed) torque than a cap start motor would have as two windings are being used. BTW, I see that a lot of these "5 HP" compressors have 3600 RPM motors and they have both start and run caps.
Hope this make some sense,
THANKS for the link! It might help! I have the same single phase schematic on the second page Except the motor terminal marking is different. Sequence is What I have = What you sent
V1 = U2, V2 = W2, X1 + U4, Z + V2,4, W = Z2,4, (unmarked) = Z
I like the circuit diagram page, that should solve the mystery as to how to connect the motor.
I'm very familiar with Dual Capacitor operation. The run capacitor is used to get some extra Hp from the unused start winding when the motor is running. However these cheap imports as using PSC motors with low starting torque. Another guy I know got one in a band saw, took the motor apart to see what the problem was. It had NO centrifugal switch. Capacitor was wired direct and connected to power only thru the power switch nothing else.
Wow....... I don't quite know how Emco could have given any more information, and still accomplished their goal of almost totally obscuring the actual operation of the unit...... That info packet is a masterpiece example of giving "almost complete" information in great detail...! In fact the necessary information may technically all be there..... and just be extremely tedious to decipher due to the way they do not tie the drawings together with common terminal IDs relating the relays and the motor lead numbers to each other.
In any case, it seems to operate the same way as the original post etc suggests for the "problem motor".... Both speeds and directions appear to use one straight winding, and one series capacitor winding. The series capacitor winding appears to be reversed for direction, and the two windings on each section are each for one of the speeds, so one is for low, and one for high.
I would see if you can find analogous relays to the Emco ones in this unit, because the taiwanese DID copy the Emco, and that may be what your friend has. if so, then you can probably use the Emco info as a guide.
I am not entirely clear on the actual problem...... I gather that SOME speeds run, but others do not...... Assuming the taiwan unit is indeed a copy, look at the Emco info and see what connections/relays are closed for the various speeds, and determine if the Taiwan clone is doing the same thing. Then see if the connections are actually MADE.
As far as I can determine, the capacitor is required for all speeds. At least it is USED for all speeds, since it is permanently connected, and both windings need to be used to run.
Are you doing this at "long range" just as we have to? I ask because it will be almost impossible to get into detail without you directly seeing the unit... His description passed through you is going to be an issue, no matter how exact you try to be. "One step removed" is hard enough..... two is nearly impossible. (It's like passing the salesman's request through marketing and on to engineering! )
Yeah lot of information to take that long way around the block. I did decipher the code I think. Had to convert motor connection labels to wire color, convert some new color to old color to get connection numbers. Then take the contact sequence chart and convert it to speed/direction connection and convert that to the motor I have! All to find it's wired like a 2 speed, 2 winding motor as I assumed but when direct wired as shown for High Speed Forward or Low Speed Forward I get both running at low speed. The guy put the lathe in gear and set to the lowest seed so revolutions could easy be counted with a revolution counter and a watch. The speed matches the speed listed for the motor set to low speed! I'm not sure exactly what the connection diagram means for 29-30 and 31-32 nor 9-10. But it seems that my assumptions are right but the motor will not run at high speed, Or at least that's what I'm being told. Seems to me 1800RPm is easy to check being that the other speed is 3600.
Another idea popped in my head, The Wire terminations are marked differently and so is the Motor color code. If someone were to try to connect the motor shown in this diagram to the switched using the colors to identify the wires there will be a problem.
My Brain storm turned out to be a light drizzle! Thought that maybe with wiring color difference it might have been wired wrong. Testing the motor leads showed the right arrangement was made.
I was searching the web and some else was looking for single phase and 3 phase 2 speed connection. All the links offered were 3 phase. However one guy responded with he has seen a motor with a switch solid state switch mounted in the motor so that is will start on low and internally the pole connections are shifted to 2 pole and the motor will accelerate to High speed.
As I mentioned above, all connections shown were hard wired direct, motor ran but only in low speed for all 4 connections.
Anyone have more info???
Hi I see I missed a question, Yes I'm doing it long range in a Forum. I would like to take voltage readings but have avoided it. Instead I had him make a 4 lamp test light as I mentioned earlier.
The motor is connected to a Mechanically operated switch. It is possible that as Duak stated the motor is to be started in low and changed to high. From what I'm told pushing the speed button will pop up and depressed direction button and removing power from the motor. The direction buttons preform an on/off function as seen in the schematic. I'm told that a rotation button and High Speed buttons must be pushed at the same time to get the switch to lock down the High Speed button. A flag that kinda tells me that dual depression might change something in the switch as I see no need for it otherwise.
As testing continued I got more questions than answers! My light bulb dummy motor connection had strange results in High speed. The guy asked if it was necessary to remove every wire from the motor as "Z" was not easy to get to. "Z" and a red wire on the motor side of the Cap. were connected but all other wires remover! He just retested with both wires removed and the results changed. Now I get the expected light pattern if the connection to the capacitor were not made. WHY??? And why did the motor start is low speed Forward with the capacitor not connected?? I had him put 1 bulb in series with the Cap. but motor would not start. Now I'm having him put 4 bulbs in Parallel to see if it starts. If so Then I attach the motor to the switch and try to run at Low speed Forward, if it starts and there are no lights lit then it's starting with out a connection to the cap.
Well, long range is tough, because you get the recipient's interpretation of what you asked, and his version of what happens.
The real problem occurs when you get a question like "Should it be smoking? You didn't ask about smoke so I didn't mention it, but it's real hot and smoking, and it's been that way for a while."
Hopefully you don't have it that bad, but it's gonna be hard, and their diagrams if no better than the Emco one won't help much.
I still think the thing is simpler than it seems.... The switching pattern is that the cap is in every setup..... the cap winding is reversed for reverse vs forward, and the "end" of the winding that gets connected to the "other side" of the mains depends on the speed selected. One end is for high, the other end is for low.
At that point, once could do the hookups with wire and a line cord and verify the run speed and directionwhen you KNOW the way it is connected. Then you can set up the switches and verify that THEY do what you did with wires. (If I were doing it, I'd have my handy-dandy "meter and variac box" along so I could check for shorts and opposing windings without having to "drop it on the mains and see what smokes".)
I did have him hard wire the motor. I told him how to the wire connections for the 4 different modes, Low Speed Forward, Low Speed Reverse. High Speed Forward and High Speed Reverse.
Motor runs Forward and Reverse as wired But all speeds are low! The Name Plate is 3425/1710 but without load it should be 3600/1800. Using the gearing on the lathe set to the lowers spindle speed he was able to confirm the lathe was running at the spindle speed listed for Low speed setting of the motor. If it would have went into 3600 I think he would have noticed it.
I agree with you, If I can get the motor to run at High and Low speed, I can make the switches work! Problem is I don't know how to get the motor in High speed! The motor wiring diagram does not leave a lot of room to change pole connections. Only connection I didn't try is connect the High Speed Winding and the Low speed winding at the same time! I have no idea what that might do!
Last edited by Froneck; 08-07-2012 at 01:09 AM.