View Full Version : the chinese mill saga continues...

03-17-2005, 07:37 PM
ok, so i got my new motor in the mail.

the new one came with jumpers on the terminals. the old one didn't have any jumpers on the terminals.

here's a pic of the new one as it came out of the box:


it's getting hooked up to a reversible switch. the switch has 6 terminals, the motor has 6 terminals but the original motor only had 4 leads hooking it up. as i already stated, it came with no jumpers at all. i spoke to aaron moss from industrial hobbies (guy who sold me the mill) and he said i need a jumper across the middle 2 terminals (as indicated by the 220v cw diagram), but my dad (an electrician) is hesitant to hook the thing up as of yet because we can't really figure how the thing reverses, seeing how that diagram has jumpers in different positions.

anybody got any ideas? i'm about to bust out the notepad and a multimeter to test what terminal does what on the switch's two positions.

03-17-2005, 08:55 PM
I could be wrong, but hook the thing up how you think it should be and 'bump' it to see if she works.

I've seen electricians do this wiring up the 25 HP 3 phase motor in my compressor, and get it wrong. The thing just kind of hummed and didn't go anywhere if I remember correctly. They finally got it right.

Likewise, I miswired a single phase 220v motor (Don't ask). Kinda ran loppsided, I knew right away something was wrong and shut it down and got it right.

My point is, no long term damage should be done as long as you're safe and know how most of it should go.

03-17-2005, 09:15 PM
ok, i figured out how the connections for the original motor worked, but i'm confused on one thing.

it's a 220v single phase 2 capacitor induction motor. there's 4 wires plus a ground to hook up. ok, so two are one leg and the other two are the other leg. from here on, i'll refer to one as black and one as white to (hopefully) eliminate confusion.

for the motor to go forwards:

for the motor to go backwards:

as you can see, two of the terminals remain the same leg, but i can't really find the logic of how this works. i just read up on how a capacitor induction motor works, but i still don't understand why there has to be two freakin sets of terminals and why only one switches. does one set charge one of the caps or something? i read that one cap is for starting and cuts out with a centrifigual switch, but the other cap is in series with the phase winding, which is the second field winding in the stator.

so i guess what i'm trying to figure out is:
1. why the heck are there four conductors on the motor rather than just two? where do both sets hook up?
2. when reversing the motor, why does only one set of conductors swap, rather than both?
3. what is the point of the second capacitor and the phase winding?

03-17-2005, 09:17 PM
doh, i forgot the whole point of all those questions:

if you look at the diagrams on the original picture i attached, 220 cw has four terminals hooked up, but 220ccw only has three. there's a scratch between where the two terminals should *logically* be jumped, but is it only a scratch or something to actually heed?

03-17-2005, 09:32 PM
I don't understand all your terminals, but to reverse a single phase motor you reverse the start winding.

03-17-2005, 09:52 PM
so does that mean that one set of terminals would be the running windind and the other is the start winding?

03-17-2005, 11:46 PM
4 schematics there on the legend plate.

Top left 120 CW? bottom left 220 CW?

Top right 120 CCW bottom right 220 CCW

I can't focus my eyes tonight or I'd tell you more. (damn thyroid/mediciene)

To reverse, it changes the Z leads polarity on the plate. Probably in the start winding. I can't see well enough to see how the 220 reverses, except I know the windings series to raise resistance so the windings won't overheat. They parallel on 120.

Usually with a reversing switch it switches the capacitor leads and applies power in both directions. either a two pole three position switch or a combination of relay and two pole 3 pos switch. That is "normal" I don't know what your machine has.


[This message has been edited by ibewgypsie (edited 03-17-2005).]

03-18-2005, 12:03 AM
Well, that is just nifty..

You have a magnifier glass on the picture page..

Z2+V2 connect to 220 A leg
U1+Z1 connect to 220 B leg
Connect windings U2+V1 no power..

220 CCW
Z2+U1 connect to 220 A leg
V2+Z1 Connect to 220 B leg
connect windings U2+V1 no power..

So if you notice, only change is to reverse Z1 and Z2 connections polarity on the circuit.

charlie coghill
03-18-2005, 09:10 PM
Psomero Clue me in how did you get the magnifer for the picture. I did not see it when I first looked at the pic.

03-18-2005, 11:45 PM
internet explorer automatically resizes images by default so they fit the screen. if you hover the mouse over the shrunk picture of a minute, a magnifier button will pop up.

anyways, i tried hooking up the damn thing today and nothing happened. i'm so pissed at this thing i'm going to throw it from my driveway in san jose all the way back to china

03-19-2005, 12:32 PM
I am confused.

Is the power on the motor like the drawing showes?

If so, check the motor internal windings with your meter. You did remove or move the lil metal jumper bars to the proper motor poles?

Possibly you have problems elsewhere like a burned contact in a switch?

Sorry you are not closer. Kinda shooting in the dark here. Post more pictures of the controls if you can.

David Cofer, Of:
Tunnel Hill, North Georgia

03-19-2005, 06:26 PM
you're confused? that makes two of us.

i did up the power exactly as the diagram on the motor shows. i tried reversing the legs also to no avail.

the switch appears mechanically sound still. i checked each terminal with a multimeter and none have any unusual resistance.

the single jumper the diagram indicated is hooked up. perhaps i should try removing it.

i guess checking the motor with my meter is my next step. i'll do that tonight and have the old man supervise...

03-19-2005, 06:42 PM
As pictured, the motor is set up for 120 volts.

Three terminals connected together each side.
I can't read the motor terminals on the ceramic block but, it showes the capacitor/start winding Z is the one with the wire jumper, the internal jumpers are parallel, probably need to remove all the jumpers and put them in right for 220 use. Center taps together to series windings, capacitor Z-leads brought out to switch/relay to reverse. (jumpers removed from it too)

If you applied 220 to the motor as jumper-wired 120 the filament winding might be burned out now. THat would have Popped or made smoke as it died.

My eyes are working slightly better today, but I still can't read the terminations on the ceramic motor block.


03-19-2005, 07:30 PM
aww, come on man. i knew better than to hook it up while it was still in the 110v jumper configuration. NOTHING happened when i hit the switch. no noise, heat, smoke, anything.

03-19-2005, 07:35 PM
Well.. bypass all the switches and apply 220 directly to the motor as hooked per the schematic.

That will identify a switch problem from motor problem.


03-20-2005, 12:20 AM
Disconnect reversing switch from motor. Mark all wires from reversing switch so you can identify each. Put the switch in forward position and use your ohmmeter to determine which ones are shorted together. Put switch in reverse position and check all wires again to see which ones are shorted together and post this info.

03-20-2005, 03:02 AM
<font face="Verdana, Arial" size="2">Originally posted by smithbrl:
Disconnect reversing switch from motor. Mark all wires from reversing switch so you can identify each. Put the switch in forward position and use your ohmmeter to determine which ones are shorted together. Put switch in reverse position and check all wires again to see which ones are shorted together and post this info. </font>

already did that. the switch's contacts are visible, so i just flipped it both ways and saw which contacts went where. i reverse engineered the wiring diagram of the original motor and then applied the same logic/process for the new motor without looking at the wiring diagram on it and they both matched.

the switch has 6 out terminals like this:


on the input, leg 1 (black or b) is the top three and leg 2 (white or w) is the botom. the middle and far right terminals are jumped vertically, which'll make sense when you see the switching pattern. (o = terminal | = jumper . = dead space, which i had to add in to fix the forum from re-spacing the damn diagram)



i'm almost positive it's a motor problem, seeing how the last motor was the problem part intially. also, i tested the switch for resistance once with an ohm meter and nothing appeared wrong with it. this is frustrating

[This message has been edited by psomero (edited 03-20-2005).]

03-20-2005, 10:33 AM
Do as ibewgypsie says and reconfigure the jumpers for 220. Take both bar jumpers out and place them between the top and bottom center terminals (U2 & V1). Leave the wire jumpers as they are. Connect your 220 line directly (do not use the reversing switch)to V2 and U1. Motor should run cw.

03-21-2005, 12:22 AM
it works. i DO NOT know what i did differently this time to make it work, but i wired the bastard up and flicked the switch and the spindle spins. time to go make up the 12 days of chips i was missing out on...