15" Wide Belt Sander won't turn off

[Josh Falcon]

So quick update. Went out for a bit tonight. First thing I did was Bill's suggestion. With power to the machine I manually engaged the armatures on each contactor. Both engaged their respective motors, so seems like the contactors aren't the issue, some good news, one less thing to worry about.

I then spent some time trying to sort out the transformer wiring. Doesn't help that it's late but I'm struggling here. Based on Alex' comment that the S wire shouldn't go to the fuse I tried to move the S wire to the 0v terminal on the upper portion of the transformer. I couldn't make it reach without pulling it completely out of the way and snaking it straight across from the middle contactor. It looked like it had been buried in the way like it was for a while. I do see that the diagram makes it look like this is the correct connection though, kinda scratching my head here.

I also tried to track down an R1 wire that Alex and the schematic indicate should come after the R wire exits the fuse. No go there either, only wire "1".

It was also pointed out there appeared to be a 2nd wire behind the "2" wire coming off the fuse. There is. It's unmarked but jumps back to the left contactor and then the middle and is sistered up to the "2" wires coming off the bottom of each. I tried to high lite the path in blue.

fuse2 by Josh Falcon, on Flickr

Anyway, I'll take another crack at it tomorrow with fresh eyes. I know I'm missing something but I'm at a loss at the moment.

[Bill Dufour]

That blue path wire is probably the low voltage control wiring. It is likely the stop circuit. I would guess it is a continous circuit from left top to right bottom. But is only connected when the coils are energized.
Bill D

[Stan Coryell]

I know I'm late to the party. Red 2 (your blue wire) is the common (neutral) to the contactors. It passes through the overload relay on the contactor. If the contactor trips on over current, it drops the neutral off the contactor. 2 red isn't in the stop circuit. Some one messed with the control circuit. You have to troubleshoot it starting with the transformer. Disconnect the low side of the transformer and measure voltage between 0 and 240, on the top of the transformer. It looks like you're missing a jumper from S to 0. You should have 240vac. If not measure from the 240 tap on the transformer to S on the terminal block above it. If you do, you are missing the jumper from S to 0. Put the jumper in and you should now measure 120 to 0 on the low side of the transformer. You should have control voltage now.
There is a problem in the control circuit. Someone tried to find it, moved a bunch of wires around, gave up and moved the Ts up to the Ls.

[Alex Zeller]

Unfortunately there's so much that's wired differently than the schematic that I would try to fix parts of it. Simply put sooner or later you may get unlucky and something will end up being shorted out causing more damage when you try to power it on. The red 2 wire should never go to the #2 fuse. If it was me I think I would just remove all of the wires and install them one at a time as the schematic says they should be. If you can't find a wire I would make one as it's possible that it was an extra that got thrown away.

[Stan Coryell]

I would not remove any wires. The single line might not be exactly what you have. I would guess there is a problem with the "emergency brake " control, at least that is the true problem. One step at a time.

1. Lift the 120 v wires off the transformer. Record position. Remove the fuses. Are there only 2? Check for a third.
2. Apply 240v power
3. Measure power where it comes to the terminal strip. R and S. You should have 240v. Measure from R at fuse holder to S (terminal strip where power comes in). This confirms you are at F1
4. Measure from R1 to S, should be 0 V
5. Replace F1 (this is where the R wire is)
6. Measure from S to R1 (1) this should be on the high side 240V tap on the transformer. You should have 240V.
7. If the above checks out, put a jumper from S to 0 on the high side of the transformer. Measure 120 to 0 on the low side of the transformer. You should have 120V on the low side.
8. Report back. Then we will tackle the low side.

[Stan Coryell]

Skip what I typed above. I missed it in the posts above.
F1 and F2 don't match the single line. That's common.
Pull the fuses and lift the low side wires off the transformer and lift that 3rd wire off F2. Run 1 red to the 240v tap on the transformer. Run 2 red to the 0 tap on the high side of the transformer. Now, put power back and make sure you have 240v Between R and S at F1 an F2.
If yes, then put the fuses back and check for 240v at the transformer.
If yes, check 120v at the low side of the transformer. It should be measured between 110 and 0. I'm not sure what E is. You might have 120v between 110 an E.
That third wire on F2 should come from 0 or E on the low side of the transformer and go to the over load on the contactors (that wire you traced blue). It is was probably also marked 2.
Don't connect anything to the low side of the transformer until you report back.

[Bill Dufour]

I would disconnect all the wires to the transformer. Then I would attach a cheater cord to the inputs and measure the out put voltage. Do it the easy way and input 120 volts and you should see 12 volts output. If it outputs 12 volts with 120 in it will do 124 volts with 240 input like it should.
I bet powering the brake while the motors are under power is bad for things and may cause damage quickly from overheating etc.
Bil lD

[Josh Falcon]

If it was me I think I would just remove all of the wires and install them one at a time as the schematic says they should be.

It may come to that. Honestly if I was more comfortable reading the diagram I would have probably already started doing that.

Stan, thanks for your replies. I followed your instructions, here's what I got,

"Pull the fuses and lift the low side wires off the transformer and lift that 3rd wire off F2." Pulled the fuses. The wire marked "3" was originally on the 110V terminal on the bottom of the transformer. It runs up to the 3rd contactor 21NC, jumps to 5L3 and then up and out to the control panel I believe. I unscrewed "3" from the transformer and left it unconnected. I left both wires ("2" and unmarked red) attached to Fuse 2.

"Run 1 red to the 240v tap on the transformer. Run 2 red to the 0 tap on the high side of the transformer." Ran the wires as indicated.With power back to the machine I got 238V between R and S at F1/F2

transformer3 by Josh Falcon, on Flickr

"If yes, then put the fuses back and check for 240v at the transformer." I put the fuses back in, got 240V between the 0V ("2" Red wire) and 230V ("1" Red wire) terminals on the top of the transformer

"If yes, check 120v at the low side of the transformer. It should be measured between 110 and 0." Measured 111V between 110V and 0V on the lower side of the transformer.


Thats where I'm at now.

[Bill Dufour]

Sounds like the transformer is working correctly. It should be supplied with 240 volts at all times since you need 120 volts to the "on " switch so it can send power to a coil.
Does the onboard amp meter move when the motors run?
Bill D

Here is a nice simple diagram of contactor wiring.
https://temcoindustrial.com/product-...hase-contactor

M1 in the circle is the coil inside the contactor, 95 and 96 are the low power contacts on the side of the three main contacts inside the contactor. I believe on the right side on yours.

[Alex Zeller]

The top terminal on the main transformer is for the 230v power coming in. Wires 1 and 2 need to be connected to the lower terminal.

Do you have a way of easily transporting it? It looks like these guys could be in your area Arc3gasses. They are listed as a repair center for power tools and welding equipment. They most likely could correct the wiring. You could give them a call and explain it to them.

[Bill Dufour]

I have no idea how the brake works. I assume it is only applied if the emergency stop button is pushed. I do not think it is applied if the belt off or feed belt off switch is applied but I could be wrong. I think the emergency off switch should be tied in series with the two other off switches.
Thinking about your wiring the most common problem with push button control is the stop switches get bad and no longer conduct power to hold the coils in. I would check each switch to see if they have any resistance both when left in the normal operating condition and also when pushed.
The emergency stop looks like it has to be twisted to come out and be turned on to allow operation.
Bill D

[Stan Coryell]

Red 3 goes to 110 on the transformer. DO NOT CONNECT IT, TAPE IT.

The mystery wire on F2 goes to 0 on the low side of the transformer. Reconnect it to 0. Measure voltage between 110 and Red 2 at the two motor contactors. It should read 120 volts. They go to that overload relay on the contactor (the clock thing, that's the overload relay). Then read the other side of the relay from 110, I think it's the yellow wire to the left of red 2. You should read 120 volts. Before checking voltage make sure the E Stops are cleared. If it gets air make sure you have air. In other words set it up to run without pushing the start buttons. check the belt limit ect. THEN check voltage.
Check back before proceeding.
Hopefully the control circuit didn't see 240 volts.

[Stan Coryell]

Just looking at the single line.
Do the above and proceed with the steps below.
Check red 5 to 110 (on the "emergency brake contactor"). It should read 120 volts. Push the E stop in and you should lose 120 volts between red 5 and 110.

Stop and check back.

[Josh Falcon]

The top terminal on the main transformer is for the 230v power coming in. Wires 1 and 2 need to be connected to the lower terminal.

Do you have a way of easily transporting it? It looks like these guys could be in your area Arc3gasses. They are listed as a repair center for power tools and welding equipment. They most likely could correct the wiring. You could give them a call and explain it to them.

Hey Alex. So the 1 and 2 wires both trace back to the R and S incoming power. Wouldn't that be the 240 to feed the top terminal?

As far as moving it easily, no. I've actually got a call out to a buddy local to see if he knows of anyone in the area who would come by and take a look.



Stan

The mystery wire on F2 goes to 0 on the low side of the transformer. Reconnect it to 0.

I dug out the "mystery wire" I mentioned earlier. Its pictured below. I may not have described it entirely accurately earlier, and my blue line doodle leaves something to be desired. Anyway, first pic is said wire and the marked 2 wire, both being originally attached to F2. 2nd pic shows connected as I understood your instruction; "mystery wire" to 0V. Note, 2 wire was re-connected F2 to 0V Is this what you meant?

For my own edification, what is the 0V terminal on the transformer doing? Whats the difference between the 0V on the top terminal and the one on the bottom?








I'm going to wait until tomorrow before I move any farther, bad things generally befall me when I try to do "one last thing" at the end of the day.

[Stan Coryell]

The high side of the transformer is hooked up correctly. I think someone confused the 2's.
F1 and F2 go to the high side of the transformer. You proved that.

In the US the transformer high side would be marked H1 and H2. The low side would be marked X1 and X0. The transformer takes 240vac (measured phase to phase) and steps in down to 120 vac (measured phase to neutral). The transformer is making the neutral. So, on your transformer the low side 0 is the neutral, common, or reference. On the high side 0 is common. I'm not sure what E is. I think it's "earth" or ground.
Your second picture looks correct.
Measure voltages as I outlined above.
Then stop and report back.

The general idea:
Now that we have the transformer fused and making 120vac, we want to hook the neutral up to the control circuit and test the E stop. So we need to run wire from the low side 0 to the contactor (red 2). Which you have done in your second picture.
For some reason this wire was on F2.

We will add the 120volt in once we are sure that the neutral (red 2) isn't messed up.

Note: I've worked on stuff from Asia/ Italy before. What the single line is calling "emergency brake " may be lost in translation. There aren't any diodes to show and kind of SCR. So to me, there isn't any motor brake. It does show some kind of solenoid.
The contactor on the right "emergency brake " has to close to allow the other two to operate. I'm guessing it's not. Someone took the single line, that's incorrect, read it wrong, and then moved some wires around. Then, they gave up and moved the T's up to L's.