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Discussion Starter · #1 ·
Hello everyone,

This is my first post here because I just inherited a Delta Unisaw 34-801 from my dad. The saw unfortunately does not start at all. I believe that my problem is the magnetic contactor in the LVC. They no longer supply or make any parts for this LVC unit. After already replacing the transformer in there I am scratching my head. I manually closed the magnetic contactor when plugged in and the motor does start. I have checked the two connections to the magnet and they are receiving voltage. For me it either has to be the magnetic connector or the switch not working. Has anyone had to replace either of these items? If so, what parts did you replace them with and did it work.

Thanks in advance for any advice.
 

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  • I manually closed the magnetic contactor when plugged in and the motor does start.
  • I have checked the two connections to the magnet and they are receiving voltage.
These two things are the correct way to go about troubleshooting your problem. Good. The second one appears to be your actual issue. However, to be certain, under what conditions did you check for voltage?

Unless you were manually holding the "ON" button closed, you shouldn't have been getting a voltage on the coil. If that is true, then I suspect that you were not checking properly, and didn't actually have that voltage. So this second statement would actually be a red-herring.

If you connected your transformer output to the relay coil of the main contactor, then you should see the contactor close.

P.S. When taking voltage measurements on your low-voltage circuits, make sure you are NOT using ground as your reference. You need to be using the second transformer wire as your reference.
 

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Discussion Starter · #3 ·
P.S. When taking voltage measurements on your low-voltage circuits, make sure you are NOT using ground as your reference. You need to be using the second transformer wire as your reference.
Its as if you knew what I was doing haha. I was checking the contacts on the switch by touching the contacts and ground but was seeing 120v on the stop and start and about 30v on the center contact. Im not very good at anything above basic electrical work. Which side on the contactor coil should I attach it too, I would be very happy if the contactor works but I only need a switch.
 

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OK, let's take it one step at a time. There are 2 red wires way up in the upper left corner of your picture.Those are the wires going to your relay coil. When they get 24 volts between them, the relay should activate.

STEP 1: Take your volt meter and measure the voltage between X2 and X1 on your transformer. These are the two red wires on the lower-right lugs (1 has a blue insulator, and the other has a black insulator).

NOTE: If by chance you are only getting about 20 volts, then the wire on H4 should be moved over to H3. But do that ONLY if you are getting 20 volts instead of 24 volts. (Edit: see new post, I should have said 30 volts, not 20 volts.)

STEP2: Never mind, let's hold off there first.

Question: See the red contact block at the very bottom-right of your picture? Confirm that the 3 wires leaving that are the same 3 wires going to your On/Off buttons. After you confirm that, and confirm the 24 volts, I'm going to have you short circuit those wires, but I wanted to get confirmation on the details first.
 

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Oops, stupid me. If the H4 wire is in the wrong place, you'll get 30 volts, not 20. And it sounds like you ARE getting 30 volts. So after confirming that, move that wire over to H3 and you should be getting the correct 24 volts that your coil wants to see.

P.S. This isn't your core problem, though. It is just something that needs to be corrected for your house's power system.
 

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Discussion Starter · #7 ·
OK, let's take it one step at a time. There are 2 red wires way up in the upper left corner of your picture.Those are the wires going to your relay coil. When they get 24 volts between them, the relay should activate.

STEP 1: Take your volt meter and measure the voltage between X2 and X1 on your transformer. These are the two red wires on the lower-right lugs (1 has a blue insulator, and the other has a black insulator).

NOTE: If by chance you are only getting about 20 volts, then the wire on H4 should be moved over to H3. But do that ONLY if you are getting 20 volts instead of 24 volts. (Edit: see new post, I should have said 30 volts, not 20 volts.)

STEP2: Never mind, let's hold off there first.

Question: See the red contact block at the very bottom-right of your picture? Confirm that the 3 wires leaving that are the same 3 wires going to your On/Off buttons. After you confirm that, and confirm the 24 volts, I'm going to have you short circuit those wires, but I wanted to get confirmation on the details first.
Maybe I am still doing it wrong but I am getting 120v from X1 and X2. I also attached the wrong photo, that is the one with the old transformer. I attached the picture with the new transformer. Though I can confirm that the three wires coming into the box and heading to the red contact block. They are also receiving 120v, I am clearly doing something very wrong.
 

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I think you have the black and red wires reversed. The black wire should go on the contact in the middle of the fuse, and the one that was there should move all the way to the right. (i.e swap far left and far right wires...leave the middle wire where it is.)

But again, do not push the start button until we check voltages. I don't want to put 120 volts into your relay coil.
 

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Discussion Starter · #13 ·
That transformer isn't labelled, How did you know where to connect each of the wires?

I think the problem is on the lower 3 wires, but I want to hear how you started out before we start moving wires.
I called around and got this transformer from a supplier who told me it should work. Here are the labels, they were in odd spots that made it impossible to see from the front.
 

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Alright. First off, disconnect ALL red wires from your transformer. I do not want any power going to your On/Off switches. I just want to check raw voltages at the transformer.

It just occurred to me that you have never said what the main supply voltage was for this saw. Is this a 240 volt saw or 120 volt? I'm going to assume 240 volt for now.

Move the top wire from H3 over 1 position to H2.
Then move the black wire from the bottom of the transformer up to H4 on the top of the transformer.

If you don't get any sparks when turning the breaker on, (yay) then I want you to measure the voltage between the lower-right and lower-middle contacts at the bottom of the transformer. Actually, you could also measure lower-right to lower-left, but I'm guessing it will be the same.
 

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Discussion Starter · #15 ·
I think you have the black and red wires reversed. The black wire should go on the contact in the middle of the fuse, and the one that was there should move all the way to the right. (i.e swap far left and far right wires...leave the middle wire where it is.)

But again, do not push the start button until we check voltages. I don't want to put 120 volts into your relay coil.
I still seem to be getting 120v almost everywhere I look. This is so difficult...
 

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Discussion Starter · #17 ·
Alright. First off, disconnect ALL red wires from your transformer. I do not want any power going to your On/Off switches. I just want to check raw voltages at the transformer.

It just occurred to me that you have never said what the main supply voltage was for this saw. Is this a 240 volt saw or 120 volt? I'm going to assume 240 volt for now.

Move the top wire from H3 over 1 position to H2.
Then move the black wire from the bottom of the transformer up to H4 on the top of the transformer.

If you don't get any sparks when turning the breaker on, (yay) then I want you to measure the voltage between the lower-right and lower-middle contacts at the bottom of the transformer. Actually, you could also measure lower-right to lower-left, but I'm guessing it will be the same.
Ok, so I wired it the way you said, no sparks, phew. Sorry this is supposed to be for 240. When I touch both wires I get 240v, when I touch each one individually I get 120v on the top. The bottom, from left to right, 120v 120v 120v 180v. Im not sure where the 24v is, maybe it is the wrong transformer?
 

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Take a piece of tape and a really big red marker, and cover your ground screw so that you never, ever, ever check a voltage to ground ever again unless I tell you to. (LOL, just kidding, but stop doing that. Do not measure anything to ground!!))

Re-check your bottom voltages, but this time, measure the voltages between each lug, not to ground. I think the screw that they have labeled XF is the second from the right. If so, that's the one I want you to measure the other 2 against.

Measure the voltage between XF and X2. That should be 24 volts.
Measure the voltage between XF and X1. That should be 120 volts.
I can't see a 4th screw, but the 180 volts between X1 and X3 sounds correct...we just don't need it.
 

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It's almost like you right behind me lol. Yes they came up exactly as you said they should.
OK! Now we're getting somewhere.

XF and X2 are the two wires you need to use.
  • Take the red wire with the blue insulator and connect it to XF
  • Take the red wire with the black insulator and connect it to X2.
Go ahead and press the On button now. Even if it doesn't work, that's OK, because now it is just very simple troubleshooting from here.
 
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