Morbark 1300 Grinder Electrical

[Tony Wells]

Greetings folks!
I have a major pain and a minor mystery on my hands. Working on a start/run/stop issue on this machine. Cat engine. Master switch on, key to crank and everything comes to life. And stays......You can turn the key back to off and remove it, still grind all you want. The only way to shut the thing down is to use the Master switch, or run around to the other side of the machine and hit the E-Stop.

Now, I have to try and explain that it has been hacked. This machine originally had a cab and grapple boom, but that has been removed. So there are a number of chopped wires. Also removed is the 5 second starter delay (PN 39250-294), and the associated slave solenoid (PN 29315-410). A lot of wiring has been modified and there are lots of dangling non-connected wires hanging out of snakeskin looms. Since it starts and runs, all electrical gauges seem accurate and functional, someone went to a lot of trouble to bypass or chop out some wiring and modules. All well and good (not really), but the customer oddly enough wants to operate it with the key. Naturally, many of the wire colors and wire gauges are no match for the schematic.
Where I am stuck is what connection is present at the key switch (presumably) that shouldn't be, or just might be on the wrong terminal so that it stays hot with the key off. I have a new key switch, but haven't put it on yet. (Grrr and extra Grrrr.....I'll not be buying any more from my Morbark distributor unless I am absolutely dying. They got gall to mark up a 50 buck switch to $166.) I've stared at it a while, but keep getting drawn off this repair to guide some guys working on the mill. Hard to concentrate on wiring when I'm explaining taper-locking shaft adapters and how to get them to pop loose so the mill can be re-centered and not rub on the end plates. This machine was fed an indigestible object about a year or so ago, and cracked one of the cast bearing housings, and actually distorted, bent, and broke a ton of stuff around the tub and mill. But I digress. Here is a link to the schematic for anyone who cares to take a look and see where I can break into the fuel solenoid circuit (best way I can think of) and shut this beast down with the key. I know the start delay is a safety feature, and will be addressed, but only after the shutdown problem is resolved. Seems like it ought to be simple, but I can't see it yet.

https://drive.google.com/open?id=1nKQO8MREFYwLXNbFiux9FgOCX7wwSrLK

That should be a shared link on my Google Drive. Feel free to grab a copy for yourself even if you just want it for your files. Note it is NOT the 1300B. Just a plain 1300. I wouldn't count on everything matching that schematic.

I got a feeling this is something simple, staring back at me, but it's been raining off and on, so I am constantly getting interrupted and just can't see it. Now I am basing my take on this as if the fuel solenoid is normally shut down, and has to see the 24 volts to pass fuel. Please correct me if I am mistaken.

Many thanks for any help. For some of you I imagine it's elementary. I think it ought to be to me, but I'm having a mental block. Could be the meds I'm on due to my ripped up discs (3 of them). No heavy lifting for me, but figure I should be able to twist a few wires together.

Tony Wells

 

[BillG]

One could spend all day following dead leads on this one, but that said you are the only one who knows what is there and what isn't. So I would start at square one which is the ignition switch, did you install the new one, I am guessing yes. If you have a PowerProbe this can be easier than using a volt meter. I have no idea what Cat engine you have an electronic one like 3406E or an earlier mechanical engine like a 3406. I didn't look at the schematic but the best way is to isolate which wire is feeding the ECM or the injection pump solenoid (depending on engine) is to follow it back to the control panel and compare to the schematic. I remember on some older equipment we would install a diode at the alternator to prevent feedback once the alternator was producing power. This kept the engine from running on when the ignition switch was turned off. It is possible that a relay or contactor may have been added that is staying energized but again with all the variables in this one you will have to trace it down.

 

[Tony Wells]

Thanks Bill,
I couldn't tell you specifically what engine is in it. I'm not on site at the moment, but will be shortly. I don't have a low voltage non-contact probe, so I'm stuck with a Simpson or a Fluke digital.

So in very general terms, I should be looking at this from the ECM or fuel solenoid back towards the source, which would be through a breaker, back eventually to the switch. I have crawled over the engine and there is an ecm, but have yet to find anything in the fuel path that would act as a shutoff.

There's no internet where the machine is, except for my phone. I may post a question or two from it later when I get over there. If I can determine what is feeding the ECM, is is safe (I know not kosher) to interrupt it to shut the engine down? It seems like I always get the call on machines that have been butchered and everyone else has given up. In a round about way, I guess that is a compliment.

On the "run" position on the key switch, there are two wires. Neither is the right size or color. They are wire-nutted(!!!) into other wires. I guess I could just tear into the loom and see where they have been spliced in and to what. Most of the original harness is there, it's just been patched and spliced into. I'm simply looking for a place to remove the 24v so it will die. That "run" position is switched properly and does go to zero with the key off.

 

[Tony Wells]

Found a wire feeding 24v to ECM any time master disconnect was on. Wire nut again. Moved it to switched supply and all is well.

 

[BillG]

Glad you got it sorted out, once in a while things do work out.

 

[ianjoub]

Now that you are fixed:

I read this title as an electric grinder! I came in here because I wondered how one would get 3 phase power (likely needed to run an electric motor for a grinder) to most sites people would use grinders at :lol:

 

[Tony Wells]

News headline: BLIND SQUIRREL FINDS ACORN!

No, it wasn’t that bad. Just need some time without distraction. The helper was late this morning so nobody bothered me.

Still need to do a little lead dressing to make it a little more presentable but the main thing was restoring a more normal operation. That happened, my customer is happy and the machine broker was told the machine was read to work (Sell, IOW). Everybody’s happy. Buyer lined up to fly in and take a look so most likely it’s a sold machine. Kind of hate to see it go. It’s easier to work on than the Hogzilla in the yard.

 

[Tony Wells]

No ianjoub, it's a Cat powered tub grinder. I have worked on a 480v 3 ph rotary screen (Mccloskey I believe) though. But all they did was put a 60hp hydraulic unit (and wondered why it got hot) there in place of the diesel and used a hydraulic motor to run the drum. It was a yard machine anyway, not for field use. That's a far cry from running a grinder though. I'm not sure it would be possible or practical to have an electric powered grinder of this size. The genset would be bigger than the grinder, which scales about 75,000 lbs as it is.

 

[John C.]

I have a customer with a Universal Refiner that is electrically powered. It is parked next to a power pole and has the switch gear on the machine. I forget how big the motor is but I'm sure no service truck crane could pick it up. The electric motor takes the place of the diesel engine on the machine.

 

[Tony Wells]

I think (if it's even acceptable to use this word) most electric grinders use finesse over brute force. Sharp edges over carbide hammers, etc. I guess there are places that the noise, the fuel cost, or other factors might make it advantageous to go electric if they can do the job. I'm not sure, but I think the electric motor limits of hp are around 450-500 hp running on 480v, so there is that too. Hard to compare to a 1000+ hp diesel. In a stationary application, they probably can hold their own just fine against similar sized machines. I've yet to work on an electric grinder, but that day will probably come.

 

[John C.]

The Universal Refiner doesn't use a big rotor with carbide bits to bust things up. They will generally do the same work and output of hog type machines. This customer's diesel engine machines are generally 450 to 600 horsepower.

 

[Tony Wells]

I looked at a video of one of their machines, and it appeared to have a rotating blade in a horizontal plane in the bottom of the tub that would cut/shred the material instead of just smashing it to bits. Probably more efficient on some materials, but I wonder how it does on heavier waste, like full stumps. I guess if it is sharp it would just shred it, but you would get a different type of material out, shape-wise. Just a different approach to a problem. And like most designs, it has its strengths and weaknesses, just like hammermills.

 

[John C.]

What I've seen of them is that that rotor carries the materials into a stationary cutter but also traps the material against it. I don't think they are as fast as a hammer mill but they also don't throw stuff over two acres of ground if they aren't kept full. Less horsepower used means less fuel used and a lot less down time changing bits and gratings. I've seen the outflow conveyors be clear full when doing lots of Douglas Fir and Hemlock stumps.

 

[Tony Wells]

Yeah, and if someone drops a tooth off an excavator into a mill.....bad news and lots of down time. You're absolutely right about the mess a hammer makes. A slow operator is always obvious when there is a lot of material around the machine. You have to keep up with the machine or it will spit half of it back out. And the wheel-loaders hate having to clean up after them.

Maybe I'll get to look at one of those electric jobs sometime. I don't know right-off anyone that uses one, just the diesel machines, except that electric/hydraulic I mentioned.