Wiring question: replacing 3Ph motor w/1ph

I recently acquired a Rockwell 46-525 wood lathe and am in the process of replacing the 3 phase motor with a new single phase 1 Hp that will for now will run on 110. The original 3 phase motor was hooked up through a three phase motor starter with slow start. I've posted a pic of the wiring diagram on ABPW. My question is : Can I (or should I ) hook the new motor up using this panel for the sake of the slow start or am I misinterpreting what the slow start means. Any suggestions on how to proceed would be appreciated. Thanks, Lenny

Reply to
Lenny
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Yes, definitely use it. If you have a power failure which then comes back on the controller will not power up the motor until you hit the start button.

L1 & L2 go to the 115V power plug T1 & T2 go to the motor. Be sure to adjust the tap on the transformer for 115V.

Art

Reply to
Wood Butcher

Art, Thanks for your reply ! To furthur prove my ignorance; Can you explain 'adjusting the tap on the transformer', starting with "where the transformer IS" ? Thanks again, Lenny

Reply to
Lenny

Unfortunately, my news server didn't get the picture you posted. I went through something similar a few years ago. I purchased a jointer that had a

3PH motor and replaced it with a single phase. In my setup, the on/off switch ran on 24V, which required a transformer to step the 230V input voltage down to 24V. If your transformer is like mine, I suspect you will see a little unit in there maybe 3-4" square with inputs labeled 120, 230, 460, 475 for the various possible input voltages. Hopefully, you have an input for 120. Mine didn't go that low and I had to replace the transformer. If you want to send me the pic, I can try to confirm.

Todd

Reply to
todd

If you post a pic of the interior of the starter to APBW I'll see if I can.

Art

Reply to
Wood Butcher

A better way to wire the single phase motor using the three phase starter is to run leads to L1 and L2 from the main. Run the lead from the output of L2 up to the input of L3. Run the two leads from L1 and L3 to the motor. This allows the overloads to be balanced and on electronic ones allow them to work correctly.

We do this when converting a three phase compressor to a single phase. The only other thing you need to do is verify that the starter will handle a single phase motor of the amperage you are installing. You may need to change the overloads and/or the starter's coil.

Reply to
Carl Stigers

Reply to
Lenny

Refer to "wiring3.jpg" posted on ABPW.

The transformer itself is on the upper left. The wire you need to move is shown on the upper right. The "L" connections to the plug are circled on the lower left. The "T" connections are indicated, however you need to determine which is 1, 2, & 3. Trace the black wires from the top of the "L" block to the "?" symbols. "T1" is directly below the "L1" wire connection. "T2" below "L2", etc.

Follow Carl's wiring suggestion for the "L" and "T" connections.

Hope this helps.

Art

Reply to
Wood Butcher

Thanks Art, According to the diagram on the cover T1 is to the left T2 in the center and T3 on the right. So I move the wire on the transformer from 200 to 115 as you marked. That's the part I understand. I'm capable of following a diagram that says take black wire from power cord and connect HERE. Connect White wire from Power cord Here. Just so you know my limitations. =0 ) With that said ; Carl wrote: "run leads to L1 and L2 From the Main" Does that mean my power cord coming in ? and is it white to L1 Black to L2 ? Carl also wrote: " Run the lead from the output of L2 up to the input of L3" Does the output refer to the black wire right above L2 and where is the input of L3 , right under L3 where the original power cord is attached now. If I picture it right it would just loop from the top of L2 around and come up under L3 right beside the wires from the new power cord. What is done with the existing wires that are coming out of the top of L1 L2 and L3 now ? Sorry to be so thick on this. If you loose patience with me I will understand.

Thanks, Lenny

Reply to
Lenny

I assume you will be getting a new power cord and abandoning the existing one. I recommend getting one with 12 gauge wires.

Power cord: Black = L2 White = L1 Green = copper strip below T3 [already has a green wire shown in your pic]

Jumper wire: From T2 to L3 [same gauge as the power cord wire] [Carl spoke in short hand. The above is what is needed]

Motor: Black = T3 White = T1 Green = copper strip [same as the green wire from the plug]

Leave the existing wires on the top of L1, L2, L3 as they are.

If you need further help ping me off group at wood butcher 007 at comcast dot net replace the obvious and remove all spaces

Art

Reply to
Wood Butcher

Thanks Art, That's all just as I thought, but I didn't want to take any chances that I was assuming to much. I have already picked up the 12-2 w/g. Looks like I'm all set.

Thanks very much to all who have helped me here. Now... who can help me with these below freezing temperatures. =0 )

Lenny

Reply to
Lenny

Let us know how it works out. Pics too.

Art

Reply to
Wood Butcher

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