15" Wide Belt Sander won't turn off

[Josh Falcon]

Hi All. Trying to troubleshoot my 15" Extrema wide belt sander's "off" issue. Not a ton of stuff online for this exact machine but the Grizzly G0819 appears to be effectively the same machine. Barring some differing control layout the internals and electrical side of things look identical. Likely cam e from the same factory.

Little back story, I acquired this machine from an old employer so I have a fair bit of time on it but was told that while it still ran fine it wouldn't turn off, you had to unplug it or cut the breaker. I finally got around to getting it into my shop and all that held true. Conveyor and head both run fine, pneumatics are all working, but none of the (5 total) off switches do anything. Plug it in, everything starts running. There are 3 emergency cut-offs, as well as the individual stops for the feed and conveyor, none do a thing.

I gave everything a pretty thorough once over, blew out the minimal dust in the electrical boxes but still nothing. I'm assuming something is foul in one of the contactors, something fused itself open? Just a guess though.

Anyone ever experience something similar or have any thoughts? I've added some pics for reference. Please let me know if it would help to see anything else.


https://live.staticflickr.com/65535/50084184632_66b0311efb_c.jpg (https://flic.kr/p/2jiLxbG)IMG_5127 (https://flic.kr/p/2jiLxbG) by Josh Falcon (https://www.flickr.com/photos/31362354@N04/), on Flickr

https://live.staticflickr.com/65535/50084184412_e7e7a21341_c.jpg (https://flic.kr/p/2jiLx7U)IMG_5117 (https://flic.kr/p/2jiLx7U) by Josh Falcon (https://www.flickr.com/photos/31362354@N04/), on Flickr

https://live.staticflickr.com/65535/50084184242_f23e933d3f_c.jpg (https://flic.kr/p/2jiLx4Y)IMG_5118 (https://flic.kr/p/2jiLx4Y) by Josh Falcon (https://www.flickr.com/photos/31362354@N04/), on Flickr

[Richard Coers]

Check the output of that low voltage power supply.

[Josh Falcon]

Thanks Richard. The current transformer? What values would I be looking for?

[Erik Loza]

Richard surely knows more than I do about WB's but the "common" answer would be a contactor frozen open. There is no gasketing know to mankind that will prevent WB dust from getting into everything. Hope you figure it out.

Erik

[John Lanciani]

Either someone monkeyed with the wiring and fubared it or contractors M1 and M2 are both welded closed. Personally, I’d suspect the former, you need to start by going through the wiring point by point and confirming it is correct.

ETA; in the horizontal cable way above the three contractors there appears to be a burnt wire buried in the left hand side. Take a look there and report back...

[Bill Dufour]

When the breaker is shut off then turned on again it does not run correct? If so the contactors are not welded closed. one or more is jammed with sawdust or something or the return spring is broken.
I would start by pulling fuse 2 and see what happens. replace fuse and then try disconnecting the start switch. If a start switch is welded closed it may bypass any stop switches.
Bil lD.

This is single phase?
I assume the big contactor is the sanding belt motor and the smaller one is for the feed belt. What is the third contactor, without overloads, for?

[Josh Falcon]

Hi John, I double checked the panel after seeing your comment. It DOES look like a fried wire in the pic but when I checked again its just a combination of the grey plastic of the cable way and a screw holding that to the enclosure that looks like a burnt/bare wire. I was hoping you caught something I missed but alas. Good eyes though. As far as someone messing with the wiring I'm almost certain the previous owner never even opened the thing up. I'm the second owner and I never once saw the guy mess with any of the electrical on the machines. I'll give the diagram another once over and double check to see if anything is out of place though.

Hi Bill, when the breaker is flipped on everything runs smoothly and yes, single phase. I'll try pulling the fuse tomorrow and see what happens. As far as the 3rd contactor on the right, I'm not 100% sure. This is where the Grizzly manual I've been trying to work from and this machine differ. Below is the Grizzly diagram and a pic of their wiring. I'm afraid my electrical diagram knowledge is rudimentary at best. I'm trying to sort through it though. I've been unable to find much of anything online for this specific machine.

https://live.staticflickr.com/65535/50085344431_3d3415f79d_c.jpg (https://flic.kr/p/2jiStXe)Grizzly Wiring (https://flic.kr/p/2jiStXe) by Josh Falcon (https://www.flickr.com/photos/31362354@N04/), on Flickr

https://live.staticflickr.com/65535/50085365056_15f171a807_z.jpg (https://flic.kr/p/2jiSA5Q)Grizzly 2 (https://flic.kr/p/2jiSA5Q) by Josh Falcon (https://www.flickr.com/photos/31362354@N04/), on Flickr

I did notice that none of the lights on the control panel come on when running though which I think would be fed by the transformer Richard mentioned, maybe? The amp meter works. I had to order a new multi meter so I'll check the output on that tomorrow and report back.

Thanks for all the help so far.

[Ron Selzer]

with the cord unplugged to the sander, push in m1 contactor and m2 contactor(should push in fairly easy with spring return)
pulling F2 out eliminates control power. If it runs with f2 pulled then wired wrong or contactor stuck.
I think m3 energizes an disk brake mounted on lower shaft or motor shaft. need to go down in basement and look at mine again
good luck
Ron

[Alex Zeller]

When the machine is unplugged are the small square blocks in the center of the contactors (lower right side of the box) out? When they are turned on an electromagnet pulls them in. They should be spring loaded so if they are out and you push on them they should go in with minimal resistance. Do it unplugged. If they are out and move in freely plug it in and see if they pulled in. The only one that should is the one connected to the emergency off switch. Pushing it in should turn off the contactor it controls. The next thing I would try is to push in both of the red buttons to stop the belt and conveyor. They may be the type of button that doesn't stay in when pushed, if so hold them in. If the belt and the conveyor stay running then it's a real good sign that someone messed with the wiring. Looking at the picture wire #9 looks like someone removed it at one point in time as the screw and plastic near it looks a little beat up. Without being there with a multi-meter it's hard to troubleshoot.

[Josh Falcon]

All good things to look at. Will check each of these out this evening and report back.

Thanks again for all the suggestions!

[Josh Falcon]

Hey all, went out and ran through a few things. Here's what I found

1) The machine DOES run with fuse 2 removed

2) All the contactors push in easily and return to the out position smoothly. All are in the out position with no power and remain out under power

3) Pushing in and holding the OFF switches has no effect while the machine is running

4) I think my photo angle was bad in relation to Alex's note about wire #9. Everything looks good there, no sign it was removed.

5) Below is a pic of the reading I get from the transformer

https://live.staticflickr.com/65535/50088584492_e56dd86699_c.jpg (https://flic.kr/p/2jja67m)transformer output (https://flic.kr/p/2jja67m) by Josh Falcon (https://www.flickr.com/photos/31362354@N04/), on Flickr

[Ron Selzer]

took another look at the original picture
SOMEONE HAS MOVED THE LOAD WIRES UP TO SAME TERMINALS ON TOP OF CONTACTORS AS POWER WIRES
To verify this please one picture further back so we can see motor wires coming in cabinet and then 2 pictures one each of each contactor
terminal screws are missing out of the belt contactor on the bottom where the wires should connect
no wires on the bottom of contactor for sanding belt either
post these pictures please
thank you
Ron

[Josh Falcon]

Thanks Ron, I think I see what you're looking at. I'll head out and grab a few more pics this afternoon.

Thanks again
Josh

[Bill Dufour]

With fuse #2 pulled it is not the control wiring. You say the armatures do not suck in under power on any contactor? This means either the contacts are welded shut or the power wires are connected wrong. If the control wires were permanently connected to the coils they would suck in the armatures.
I would guess the coil voltage requirement is too high, connected wrong at the transformer, so they bypassed the coils. This means the overloads are not in the circuit as it is now.
I would check each coil for continunity and jump each one in turn with the correct votage to see if things move.
Bil lD

[Josh Falcon]

Hi Ron, I think I see what you're looking at. I'll snap a few pics this afternoon and let you know.

Thanks again

[Alex Zeller]

According to the schematic if fuse 1 is removed and it runs then M1 AND M2 are either bypassed or the contacts are stuck. I can't see both of them going bad at the same time. Normally when they go bad they don't work. I've only seen one out of more than a hundred I've had to replace over the years at work that had the contacts welded closed. That was due to a motor that burnt up and the current draw far exceeded what the contacts could handle. The 'square' box on top of the contactor was stuck in the down position. The way contactors are made is the spring is under the contact points. So if they are fused shut the spring is compressed.

Knowing this I just looked at the picture of the wiring and it looks like T1 and T2 look to be on the same side of the contactors and L1 and L2. If so that's your problem. They should be on opposite sides of the contactors.

[Josh Falcon]

Bill, thats correct, the contactor armatures remain out under power. Starting to think the PO did mess with the wiring based on the comments.

Ron, below are some close-ups of the contactors as well as a shot showing where the power comes in. Think we may be onto something about the wiring having been messed with. Not sure why but knowing the PO as I do nothing would surprise me.

https://live.staticflickr.com/65535/50090585523_6c42f080ef_c.jpg (https://flic.kr/p/2jjkkWT)Enclosure Labled (https://flic.kr/p/2jjkkWT) by Josh Falcon (https://www.flickr.com/photos/31362354@N04/), on Flickr

https://live.staticflickr.com/65535/50090518868_c655589c2f_c.jpg (https://flic.kr/p/2jjk18E)Incoming Power (https://flic.kr/p/2jjk18E) by Josh Falcon (https://www.flickr.com/photos/31362354@N04/), on Flickr

https://live.staticflickr.com/65535/50091097361_0e0405b183_c.jpg (https://flic.kr/p/2jjnY6F)Sanding Head Contact 2 (https://flic.kr/p/2jjnY6F) by Josh Falcon (https://www.flickr.com/photos/31362354@N04/), on Flickr

https://live.staticflickr.com/65535/50091333037_78a79a827d_c.jpg (https://flic.kr/p/2jjpba4)Sanding Head Contact 1 (https://flic.kr/p/2jjpba4) by Josh Falcon (https://www.flickr.com/photos/31362354@N04/), on Flickr

https://live.staticflickr.com/65535/50090518728_3219b13e6b_c.jpg (https://flic.kr/p/2jjk16f)Conveyor Contact 1 (https://flic.kr/p/2jjk16f) by Josh Falcon (https://www.flickr.com/photos/31362354@N04/), on Flickr

https://live.staticflickr.com/65535/50091333147_e23532d2d9_c.jpg (https://flic.kr/p/2jjpbbX)Conveyor Contact 2 (https://flic.kr/p/2jjpbbX) by Josh Falcon (https://www.flickr.com/photos/31362354@N04/), on Flickr

[Bill Dufour]

The contactor switches and the overloads are bypassed. Power should come in to L1 then out to T1, L2 to T2, and L3 to T3 when it is pulled in. They do not use one contact number since there are only two hot leads in single phase power.
The only confusion is that the overloads (if present) plug into the output (T) terminals then the output wires connect to the overloads.
How many amps are the overloads set for, I can not read them from the picture. How does that compare to the motor nameplate amps.

They have it set so that power comes in to L1 and L2 like it should. Then they have wrongly connected the output wires to L1 and L2. So they are just using the L-terminals as terminal strips.

The way that panel is set up power should flow from top to bottom in each contactor then out the bottom to the load wires.
Bil lD

[Bill Dufour]

The sanding head contactor is using L1 and L3. The other two contactors are using L1 and L2. The forth terminal on the right side of the contactors is a low power switch, it may be low voltage as well. Likely for the control wiring or a pilot light. Possibly to a relay to turn on the dust collector.
Bil lD

[Josh Falcon]

Thanks Bill, Alex. I think the PO bypassed the contacts based on what you all have pointed out and looking more carefully at the schematic. Any ideas why one might do this? Knowing the PO, I'm assuming something was wrong but instead of fixing it the guy just told his electrician to get it running as cheaply as possible. I'm going to try and revert everything back to the factory setup and we'll see where that gets us.

As far as the overload relays, the sanding head looks to be dialed to about 26 amps, which should be about right. The conveyor looks to be set as low as it will go, below the first marking of 1.3A. I'll confirm the values on the motors and report back.

Thanks again everyone. Hoping to get this sorted soon.

[Alex Zeller]

Did the PO have employees? It's possible that an employee thought that it was a planer that could take 1/8" off in one pass. The fact that they did both the sander and the conveyor tells me they didn't understand the tool. Get it wired correctly and then you can troubleshoot any problems.

Even with the contactors bypassed they should still work. If you plug it in, reset the off button, then push in either one of the green buttons the contactor it controls should pull in. The white 'button' with the green ring around it I assume is the "power source" light to let you know the tool has power. Is it lighting up when plugged in? If not I'm guessing that the transformer is the problem. It doesn't look correctly wired. I think the S wire should be going to the "0" volt terminal on the top of the transformer. Just an FYI, the round transformer above the square one is what measures the current.

As always unplug it before doing any work inside the electrical panel. Also I wouldn't use the Grizzly schematics as they look a little different. The one on the inside of the cover should tell you everything you need to know.

[Alex Zeller]

Here's my best guess on wiring. On the large contactor the two black wires (I can't see any markings on them), one red (1L1) and the other white (5L3) should be connected to terminals 2T1 and 6T3. On the contactor next to it the black wires on 1L1 (no label) and 3L2 (V2) should be connected to 2T1 and 4T2. All 4 of those wires look like they've been moved. The wires under the middle contactor that I suggested look incorrect look to be the R and S wires. They are black wires going to the left most contactor and from it to the center one. From there they used red wire. The one labeled R should go to fuse 1. They then call it R1 and it should be the wire connected to the 230v tap on the transformer. The other red wire labeled S should go directly to the 0v tap on the transformer.

If that wire is not connected that's dangerous since it's one of your two 240 wires and it has no fuse on it. If it shorts to ground it'll trip your breaker. If you are connected to a 30 amp circuit that's most likely more than the smaller red wire can handle which could cause a fire. I wouldn't plug it back in until I could find that wire.

[Josh Falcon]

Thanks Alex, this is really good info, I appreciate you being so thorough.

To answer your questions, the power source light doesn't come on under power, no. The amp meter gives a reading while running.

Employees? Yes. While I was there everyone knew what they were doing, this machine ran fine. In the 2-3 years after I left and before I acquired the machine, no telling. My guess would be something went (maybe the transformer like you mentioned?) and instead of diagnosing/fixing it proper they went the least cost, "make it run" method. Sometimes a place for that approach, no doubt, not my first choice.

Hoping to spend some time on it tonight and will follow up on your suggestions. Will report back where I land.

Thanks again

[Josh Falcon]

So I was able to spend some time on the wiring last night. I think I have things back to how they should be. I tossed the Grizzly paperwork and used the diagram with the machine and I THINK I've got everything sorted. Below are some pics and notes on where things stand now;

Alex, specifically in response to a few of your watch-outs,

1) On sanding belt contactor, Red (1L1) and White (5L3) wires previously installed up top were connected to terminals 2T1 and 6T3 on bottom

2) On conveyor contactor, black wires on 1L1 (U2) and 3L2 (V2) were connected to 2T1 and 4T2 on bottom

https://live.staticflickr.com/65535/50096729398_6eda62fd0f_c.jpg (https://flic.kr/p/2jjSQiL)Sanding Head Rewire (https://flic.kr/p/2jjSQiL) by Josh Falcon (https://www.flickr.com/photos/31362354@N04/), on Flickr

https://live.staticflickr.com/65535/50097305266_55c850156b_c.jpg (https://flic.kr/p/2jjVMuw)Drive Motor Rewire (https://flic.kr/p/2jjVMuw) by Josh Falcon (https://www.flickr.com/photos/31362354@N04/), on Flickr


3) I traced the R and S wires. Starting from the left most contactor (sanding head) they move to the center contactor (conveyor). R wire then runs through fuse 1, and then to the 230V terminal on the transformer The other red wire labeled S runs through fuse 2, then to the 0v terminal on the transformer.

https://live.staticflickr.com/65535/50097305816_d26b15b4c8_c.jpg (https://flic.kr/p/2jjVME1)Fuses (https://flic.kr/p/2jjVME1) by Josh Falcon (https://www.flickr.com/photos/31362354@N04/), on Flickr

https://live.staticflickr.com/65535/50096729283_e10d175657_c.jpg (https://flic.kr/p/2jjSQgM)Transformer Detail (https://flic.kr/p/2jjSQgM) by Josh Falcon (https://www.flickr.com/photos/31362354@N04/), on Flickr

So after I moved these things around and made sure everything was lining up with the diagram I plugged it back in and flipped the breaker and.............................nothing. This is what I was expecting considering where things started out. The power indicator light still doesn't light up so based on the comments it sounds like the transformer is shot?

Any suggestions on how to verify that? Current from the 230v and 110V terminals? I pulled the transformer out just to see if there was anymore info on it but its just what you see in the pics. I tried a google search for the specific model number but didn't get anything. Can anyone tell me how to spec a replacement?

Again, thanks for all the help.

[Jeff Dymond]

On the sanding head contractor what are the gray rectangles that say remove before operating?

[Josh Falcon]

On the sanding head contractor what are the gray rectangles that say remove before operating?

Good question. Not sure. I imagine they've been there for the life of the machine but I've been wrong once before in regards to this thing.

[Ron Selzer]

"I traced the R and S wires. Starting from the left most contactor (sanding head) they move to the center contactor (conveyor). R wire then runs through fuse 1, and then to the 230V terminal on the transformer The other red wire labeled S runs through fuse 2, then to the 0v terminal on the transformer."

based on the pictures just posted and the above statement you have that wire in the wrong spot on the transformer
the S wire needs to land on the top of the transformer (240 side)not feeding the fuse
the #2 fuse should be fed from the bottom of the transformer (120 side)
You should read 230(nominal voltage, actual anywhere from 210-240 actual) between them. Top of transformer
To check the transformer once you have 230vac on the top, the bottom should output 120vac(nominal voltage, 100-130 actual)

out of time will check back around midnight

[Bill Dufour]

With the power on use a dry piece of wood, 12 inches long, to push in each contactor armature in turn and see if their motor runs. Wear real shoes and keep your other hand in your pocket while doing this. Also look at the control panel lights when you do this.
Is that just a transformer to generate 110 volts? you could get power directly at 120 volts if you have neutral to the machine. Or is that transformer part of the big black coil transformer above that is to measure current draw?
Since they did not bypass the lone contactor without overloads I wonder if the overloads are too small and kept tripping out. Checking for continuity through the overloads will not prove anything. I bet they conduct lower power fro ma meter with no problem and complain under full voltage and current.
Hopefully the overloads are a standard size or if worst comes to worst a new DIN contactor and overload is not too expensive.
Bill D

Any chance there is a safety switch and it will not run with the control panel door open. My lathe is set up that way.It may be an OSHA requirement now. There is a safety switch like a refrigerator and the power switch must be rotated off for the cabinet door to open. It moves both a switch and a locking lever .

[Alex Zeller]

According to the schematic on the door the S wire shouldn't go to fuse #2. That's a problem. It should wrap around the current sensing transformer (the round one), go to the left most contactor, then to the center contactor, and finally to the upper terminal strip on the main transformer labeled "0" volts. Fuse #2 should have the 1 and 3 wires going to it. Fuse #1 also looks wrong. Opposite the R wire should be a wire labeled R1. That wire should go to the upper terminal of the main transformer labeled "230" volts. Right now wire "1" is doing that. Wire "3" isn't suppose to go to the main transformer at all. Wire "1" should be going from the lower terminal labeled 110v on the main transformer to fuse #2. It kind of looks like there's a second wire below the "2" wire on the fuse block. The "2' wire should never go to the fuse block.

I think someone had no idea what they were doing. Possibly they changed a part like the transformer, got the wiring wrong, and then just did what they had to so it worked. I think what you are going to need to do is start tracing each wire out and make sure it's going to the correct location. If you aren't 100% comfortable doing so do you have a friend who can come over? It would be easier with a second set of eyes.

[Josh Falcon]

I think someone had no idea what they were doing. .

That's highly possible considering where the machine came from.


I'm going to take a step back and try to trace all the wires through the diagram. Truth be told, I follow about half of it, the rest I'm a little lost on. I may try to high-lite the wire paths on the pic and see where things are going astray.

The S wire does wrap around the current sensing transformer, then to left most contactor (5L3), and then to the center contactor (3L2). After that (now red wire) it goes to the fuse and from there (now labeled "2") onto the 0V on the lower strip of the transformer. Sounds like that last bit is wrong per your's and Ron's comments.

The R wire goes to the left most contactor (1L1), then to the center contactor (1L1). After that (now red wire) it goes to fuse and then (now labeled "1") onto the 0V on the lower strip of the transformer. Also sounds like that's incorrect.

I need to trace back wire #3 currently attached to the transformer as well.

I'll be back out there tonight to see what else I can sort through. I have a few other things to check out and questions to answer.

Thanks again for everyone's help and patience, really appreciate it.

[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.

https://live.staticflickr.com/65535/50099455237_590d8b7513_c.jpg (https://flic.kr/p/2jk7NAZ)fuse2 (https://flic.kr/p/2jk7NAZ) by Josh Falcon (https://www.flickr.com/photos/31362354@N04/), 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

https://live.staticflickr.com/65535/50102004262_4dc27af2dd_c.jpg (https://flic.kr/p/2jkkSkG)transformer3 (https://flic.kr/p/2jkkSkG) by Josh Falcon (https://www.flickr.com/photos/31362354@N04/), 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-guides/contactors-and-overloads/1-vs-3-phase-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?
https://live.staticflickr.com/65535/50102683901_66daca70df_c.jpg (https://flic.kr/p/2jkpmnB)

https://live.staticflickr.com/65535/50102932267_959c4f741a.jpg (https://flic.kr/p/2jkqCcM)





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.

[Bill Dufour]

I am not sure how the e-brake works. It may be spring loaded on and needs power to pull the brake off so things can turn. Or it could take power to apply the brake and no power to the brake circuit means no brakes.
Spring loaded apply would be the safest method.
Looking at the first diagram it looks like you have to push in a button to engage the e-brake. As soon as the e-brake button is released the e-brake is also released.
Does pushing in the e-brake button make the contactor move?
Bill D

[Stan Coryell]

The single line does not show any electromechanical brake. At least not that I can see.
I suspect the circled M3 is the actual E stop switch and that switch is used to turn the main contactor (M3) off and on. The E stop either breaks 6 and 7. or 5.
The last set of instructions will tell us if it's 5.
Once we have common (red 2) to M3 contactor and possibly M1 and M2, we will work at the 120 volt (red 3).

[Josh Falcon]

Thanks again guys. Unfortunately didn’t have time to get out to the shop today but I’ll have a few hours tomorrow, will update everyone then.

Thanks
Josh

[Josh Falcon]

Hi All

Stan, here's what I got based on your instructions

"Measure voltage between 110 and Red 2 at the two motor contactors. It should read 120 volts" I got 113V between 110V on transformer and red 2 wire on each contactor. Got the same reading on the terminal to the left of 2 wire (circled in blue below)

https://live.staticflickr.com/65535/50108345458_dbdeb6a4af_c.jpg (https://flic.kr/p/2jkUnmE)contactors3 (https://flic.kr/p/2jkUnmE) by Josh Falcon (https://www.flickr.com/photos/31362354@N04/), on Flickr

"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." I get 113V between 110V on transformer and red 5. I then engaged the E stops one at a time (2 pushbutton and the E bar in front of the conveyor, still got 113V between 110V and red 5.

[Stan Coryell]

So far:
The transformer works
All three contactors have common.
The overloads aren't triped.

[Stan Coryell]

So far:
The transformer works
All three contactors have common.
The overloads aren't triped.

Land 3 back on 110 (low side of transformer )
Measure between 0 (low side of transformer) and (on the terminal strip)
6
8
10
Also measure between 0 and (at the contactors)
Red 8
Red 10
If you measure 120v on all, try to start it, stop and report back.
If you measure 0v, trace the wires from the close coil (red 5 and the other one buried in the upper right back) on the "emergency brake " contactor. Stop report back
I suspect they go to "sol" I'm not sure what that is.
I think the emergency brake contactor (M3) has to close for the M1 and M2 to function. But there might be order of operation. That's why there's a NC auxiliary on M3.
More than likely the "panic bar" or relay associated with it are the culprit.
Do the pneumatics have any electrical components ?
I think you have the wiring back to factory.
The single line isn't right. At least it's missing something.

[Bill Dufour]

I guess "SOL" is a solenoid to shift he brake lever on/off?
Bil lD

[Stan Coryell]

My guess is "sol" is a latching relay that breaks red 5 and red 3 when the "panic bar" is pushed.
Is there an electromechanical break ?
Either way, I think M3 needs to be closed to get M1 and M2 to function.

[Josh Falcon]

So thought we had a breakthrough just now, but one step forward, one step back.

I connected Red 3 wire to 110V on the bottom of the transformer. I cut power on to the machine and heard a contactor click, I had left the front E stop engaged from the night prior, so it seemed like I had power to the panel. I measured from 0V to 6, 8 and 10 on the terminal strip, 110V to all three. Same from 0V to 8 and 10 on the contactors. I made sure all the E stops were clear and tried starting the machine and nothing.

I went back and tried to find what happened and noticed Fuse 1 blew. The machine will still turn on by manually engaging the contacts but I no longer have 240v to the top of transformer or anything after.

I have a few pics of the braking system (pneumatic actuated) and the various limit switches at the head and "panic bar" that I'll upload when I have a few min tonight. I've ordered some more fuses in the meantime based on what was in there previously (Bussman ACG-6 Fast Acting).

[Stan Coryell]

You haven't taken any steps backwards.
120 volts at 6, 8, and 10 tells us: you have power at the
E stop, M1 stop, and M2 stop.
I seems the fuse blew when you pressed one of the two start buttons. Next step:
1 power off
2 replace fuse (it should be 1 amp not 6) you can leave the 6s for now
3 lift red 9 and red 11 off M1 and M2
4 restore main power
5 clear 1 E stop at a time checking power at 110/0, stop if you lose 120 volt and report back.
6 press start 1 (nothing will happen) check power at 110/0. If fuse blows, replace
7 press start 2 and follow same procedure as start 1

With red 9 and red 11 lifted, we are able to check for shorts between the start buttons and the contactor, excluding the contactor. If pressing one of the start buttons blew a fuse, trace 9 or 11 back to the start buttons. Look for a pinched wire, landed wrong, ect.
If fuses did not blow: land red 9 on M1 and press start 1, check 110 to zero, repeat for red 11 and M2

Note: It's possible it took a few minutes for the fuse to blow and it has nothing to do with you pressing buttons.
I would: trip all E Stops, replace fuse, restore main power, add wait about 10 minutes. Check power at 110/0. If you have 120 volts proceed with the steps above.

Trip means to set so the machine won't run
Clear means to set so the machine runs

I would not keep pushing those contactors in manually. I won't tell you anything a meter can't. You also run the risk of damaging something.

[Josh Falcon]

Thanks Stan. The fuses should be here tomorrow so I'll reinstall and run through the sequence you outlined.

In the meantime here are some photos of the various limit switches and the motor brake, for reference, if necessary. One thing I forgot to mention was that the air line from the solenoid to the brake was completely gone when I got the machine. I replaced it before we started trouble shooting the electricals.

Panic bar switch
https://live.staticflickr.com/65535/50115684321_d3cd5fc058_c.jpg (https://flic.kr/p/2jmxYWM)

https://live.staticflickr.com/65535/50115684206_c1517cac87_c.jpg (https://flic.kr/p/2jmxYUN)

Belt limit switch (2X)
https://live.staticflickr.com/65535/50115114803_a5163f76d2_c.jpg (https://flic.kr/p/2jmv4Dv)

Belt limit wiring
https://live.staticflickr.com/65535/50115683511_218c944630_c.jpg (https://flic.kr/p/2jmxYGP)

Motor brake
https://live.staticflickr.com/65535/50115113988_71789d79d7_c.jpg (https://flic.kr/p/2jmv4ps)

https://live.staticflickr.com/65535/50115113873_b2982e2157_c.jpg (https://flic.kr/p/2jmv4nt)

[Erik Loza]

Josh, FYI that you appear to be missing a V-belt. Maybe you caught that already. Or does the upper pulley only take one? Every WB I have experience with has two, if not three belts. Looking good, by the way.

Erik

[Bill Dufour]

I am surprised the panic bar switch is "normally open" In my experience stop switches should be normally closed for safety sakes. the way that is wired if the wires go bad the switch has no way to turn off the power.
Bill D

[Bert McMahan]

If a contactor blew in the open position and he didn't have spares he might've just said screw it, I need it running now not 3 days from now and jumped over the contactors.

[Josh Falcon]

If a contactor blew in the open position and he didn't have spares he might've just said screw it, I need it running now not 3 days from now and jumped over the contactors.

There was a lot of "screw it" going on in this place. I'm certain whatever the proper repair was was more $$ than the "grip it and rip it" approach, hence where we are now.


Josh, FYI that you appear to be missing a V-belt. Maybe you caught that already. Or does the upper pulley only take one? Every WB I have experience with has two, if not three belts. Looking good, by the way.

Erik

Yeah, I have a replacement I just havent gotten around to putting it on. I hadn't planned to run it under load until I got all the electrical stuff sorted. I'm actually wondering if it broke at some point and thats what decapitated the brake air line.


I am surprised the panic bar switch is "normally open" In my experience stop switches should be normally closed for safety sakes. the way that is wired if the wires go bad the switch has no way to turn off the power.
Bill D

Totally possible the switch has also been messed with at some point, I might even put money on it. Stan has been a HUGE help so far so hopefully we can track down the issue.

[Steve Jenkins]

I’m no help on this but want to say how impressed I am with the detail of the help you’re getting. People are spending a lot of their time diagnosing the problems. I’m not surprised.

[Josh Falcon]

I’m no help on this but want to say how impressed I am with the detail of the help you’re getting. People are spending a lot of their time diagnosing the problems. I’m not surprised.

Absolutely agree, very grateful for everyone that’s replied so far. I’m learning a lot as well, I’d be lost without the help I’ve gotten so far.

[Dave Sabo]

https://sawmillcreek.org/images/misc/quote_icon.png Originally Posted by Erik Loza https://sawmillcreek.org/images/buttons/viewpost-right.png (https://sawmillcreek.org/showthread.php?p=3037669#post3037669)
Josh, FYI that you appear to be missing a V-belt. Maybe you caught that already. Or does the upper pulley only take one? Every WB I have experience with has two, if not three belts. Looking good, by the way.

Erik



Yeah, I have a replacement I just havent gotten around to putting it on. I hadn't planned to run it under load until I got all the electrical stuff sorted. I'm actually wondering if it broke at some point and thats what decapitated the brake air line.

Hope you ordered two belts, the one in the pic looks a bit tired. Even if not, it's better to change out multiple belts in sets.

[Josh Falcon]

Hope you ordered two belts, the one in the pic looks a bit tired. Even if not, it's better to change out multiple belts in sets.

It was a matched pair, yes.

Fuses arrived so I went out and made some progress. Here's what I did.

1) Replaced fuses, E-stops tripped, turned on power. Waited ~10 min, measured 112V between 110/0V
2) Turned power off, disconnected Red 9 and Red 11 from M1/M2
3) Power on
4) Cleared E-stop on back of machine, measured 112V between 110/0V
5) Cleared E-stop on front control panel, M3 contactor released, measured 112V between 110/0V
6) Pressed Start 1 (sanding head), green light lit up while pressed, fuses checked out OK, measured 112V between 110/0V
7) Pressed Start 2 (conveyor), green light lit up while pressed, fuses checked out OK, measured 112V between 110/0V
8) Power off, reconnected Red 9
9) Power on, pressed Start 1 (sanding head), F1 blew. Amp meter jumped to about 5 amps for a split second
10) Power off, replaced fuse, reconnected Red 11
10) Power on, pressed Start 2 (conveyor), Conveyor operates! Pressed stop and start a few more times and the conveyor turns on and off as it should

I took a quick look to see if I could see if anything looked like it could be shorting out in the control panel or the enclosure but nothing jumped out. Could the M1 Contactor be the issue? I look forward to any and all hypothesis.

Thanks again everyone!

[Bill Dufour]

Disconnect the power out wires on the overload for the sanding head and try to turn it on and see if the contactor will stay closed with 240 volts at the output terminals. While they are both disconnected check the resistance from each of those wires to ground and to each other.
I guess since the motor ran before it is okay. maybe the contactor or overload has a internal short between poles or a short to ground.

[Stan Coryell]

The close coil for M1 appears to be shorted closed.

Check one thing before we proceed.
1. Lift the yellow wire (A1) from N.O. 13, leaving red 9
2. Measure voltage between the load side of the overload relay(yellow wire which ends up at A2) to red 9, while pressing the M1 start button. You should have 120 volts. If not stop and check back.

Those two yellow wires on M1 should go to, if I remember correctly, A1 and A2. A1 and A2 are the control power for the close coil. A1 should land on N.O. 13 along with red 9. A2 should be the load side of the O.L. relay. This is not what the single line shows. Yours looks right, but it's hard to tell from the pictures. Lift the wires off of A1 and A2. you should be able to read resistance between A1 and A2. Maybe 10 ohms? I'm not really sure. Yours will read 0 ohms, hence it is shorted closed. I can't say I've ever had a coil do that. They usually short open.

On NEMA motor starters coils are easily swapped, 2 screws and 2 wires. I can't say for IEC.

Your M1 isn't just a contactor, it's a motor starter. It has overload protection and auxiliary contacts. The only thing bad is the close coil, you may be able to replace just that. CN-25 is the size. With that and the manufacturer, you may be able to source a replacement coil. However, if it were me, I'd change it to something I could get locally. I use Colonial up here, they cary Square-D/ Schneider. I'd be happy to call and get a quote for you.

[Stan Coryell]

Re:
"I am surprised the panic bar switch is "normally open" In my experience stop switches should be normally closed for safety sakes. the way that is wired if the wires go bad the switch has no way to turn off the power."

We don't know how the limit switch is being used. It looks like a plunger type. Remember, N.O. / N.C. refers to the switch in your hand. In "clear" the N.O. contacts may be closed.
Or, there maybe a relay hidden somewhere. When the switch makes it puts power to the relay, opening 3 and 5 and putting power to the air brake. All speculation with out a proper single line.

[Stan Coryell]

Silly question.
Is the pneumatic brake disengaged, prior to pushing M1 start? Not that it has anything to do with F1 blowing, just curious.

[Josh Falcon]

Silly question.
Is the pneumatic brake disengaged, prior to pushing M1 start? Not that it has anything to do with F1 blowing, just curious.

Yes. The break engages when any of the E-stops are tripped and disengages when theyre cleared.

I'll run through procedures outlined above this evening and report back.


However, if it were me, I'd change it to something I could get locally. I use Colonial up here, they cary Square-D/ Schneider. I'd be happy to call and get a quote for you.

I appreciate the offer Stan. I was able to find an exact match for the M1 contactor online fairly easily. The brand is Taian, looks to be a lot of them out there. I figured it wouldn't hurt to have complete new unit just in case. I don't have a lot of $$ into this thing presently and I was anticipating having to replace something anyway. If this is all it needs I'll still be making out real well.

[Josh Falcon]

Hey all, sorry for the radio silence last few days, nothing new to report. Hoping to get an extra set of hands tomorrow to check the M1 contractor one last time per Stan’s most recent message, will report back on that tomorrow. The new contractor should be here Thursday so hopefully will have some good news by end of the week.

Thanks again for everyone sticking with me.

[Josh Falcon]

Check one thing before we proceed.
1. Lift the yellow wire (A1) from N.O. 13, leaving red 9
2. Measure voltage between the load side of the overload relay(yellow wire which ends up at A2) to red 9, while pressing the M1 start button. You should have 120 volts. If not stop and check back.


New contactor showed up today. Before I dig in and replace I wanted to address this real quick. I measured between Red 9 and what I think is A2 and I got 9V (with the A1 yellow removed) . When the M1 start button was pushed I got 113V, so sounds like everything checks out there? I took some detail photos of the M1 contactor for my reference, added below just in case. I circled in blue where I took my readings mentioned above.

My plan is to pull the contactor out this evening and see where we land. Wish me luck!


https://live.staticflickr.com/65535/50144556672_e3d624104f_z.jpg (https://flic.kr/p/2jp6XFW)M1 detail 1 (https://flic.kr/p/2jp6XFW) by Josh Falcon (https://www.flickr.com/photos/31362354@N04/), on Flickr

https://live.staticflickr.com/65535/50144546987_fc5cebf913_c.jpg (https://flic.kr/p/2jp6UNX)M1 detail (https://flic.kr/p/2jp6UNX) by Josh Falcon (https://www.flickr.com/photos/31362354@N04/), on Flickr


https://live.staticflickr.com/65535/50144547272_48bc80a1a7_c.jpg (https://flic.kr/p/2jp6UTS)overload detail (https://flic.kr/p/2jp6UTS) by Josh Falcon (https://www.flickr.com/photos/31362354@N04/), on Flickr

[Josh Falcon]

Well, I pulled the old contactor, wired up the new one, flipped the breaker and were back in business!! Motor fired up, conveyor runs, all the stops work, brake engages, everything checks out. I'm super excited to have this thing running. Few things to finish up, belts, piping some dust collection, getting it on the mobile base but I couldn't help but run a few pieces through this evening and its working great.

Big thanks to everyone who helped out along the way and stuck with me through all this. Huge thank you to Stan for all the detailed responses! This thing would still just be taking up space otherwise.

Josh

[Ron Selzer]

Well, I pulled the old contactor, wired up the new one, flipped the breaker and were back in business!! Motor fired up, conveyor runs, all the stops work, brake engages, everything checks out. I'm super excited to have this thing running. Few things to finish up, belts, piping some dust collection, getting it on the mobile base but I couldn't help but run a few pieces through this evening and its working great.

Big thanks to everyone who helped out along the way and stuck with me through all this. Huge thank you to Stan for all the detailed responses! This thing would still just be taking up space otherwise.

Josh


Glad it finally came together for you
Ron

[Stan Coryell]

I'm glad your machine is back up. It was a fun exercise. That's the first time I have heard of a coil shorting closed.

In the future:
This control circuit is 120 volts AC.
120 and 0 (the 0 is "common or neutral). NEMA transformers would be labeled X1 and X0, as I mentioned earlier.

A quick lesson in volts.

Voltage is a measurement between potential. Your home lighting and receptacles use the same power as our control transformer produces, or a "hot" and a "neutral". If your home has a metal water service, you should be able to measure "potential" or voltage between the "hot" and a water pipe even though the water pipe isn't part of the circuit.
The reason I mention this is because some control transformers don't produce a neutral. They are marked X1 and X2 (if they do use X2 as a neutral, X2 will be grounded to the equipment chassis). They simply step voltage down, say 60 volts on each "leg". This scheme wouldn't change our troubleshooting steps, but it would change our voltage readings.

One more thing to remember, voltage flows through a conductor. For example, a coil or pilot light may become conductors looking for potential. If I'm not sure of a scheme, I'll lift wires as Josh did, to eliminate the chance of back feed through an unknown component.

I can't stress enough to not make assumptions. Start where power comes in and work through the scheme. If the scheme isn't working correctly do NOT push contactors closed or "jump" things out. DO NOT under ANY circumstances apply unfused power or power from another source. Unless you have NO doubt what the failure is, like, bet your life on it. Just keep working through it with your meter. Bad things happened when you think you are smarter than the equipment. Trust me.

Stan

[Earl McLain]

This has been an awesome thread to follow. Speaks of many good things about this community. Glad to see a positive outcome in the end!! Josh's persistence left many of us with a great education. Thanks to all!!
earl