Coffing 1/2 ton hoist? Need help...

[Jason280]

I recently picked up an electric Coffing 1/2 ton hoist, and I am not sure what to do with it. I originally picked it up just to salvage the chain out of it, but now I am considering actually trying to get it to work. New, these things go for over $1500, and used models hover around the $700 range. If I can get it to work, it would be a great addition to my new shop. If I can't, then I am really out nothing (and still get the chain).

I really don't know the history on the hoist, other than it has spent some time outside. The housing seems to have been well sealed, although it was a bit compromised on the end with the mechanical brake (looks like it may have been dropped).

 

[Jason280]

The biggest "if" so far is the electric motor, which is a pretty big one. It can run 120/240 volts, but I can't make out much of the data plate.








Here is what I assume is the "motor starter", which I believe also drops down to low voltage for the wired remote.

 

[Jason280]

Here is the other side, the mechanical brake assembly. It also has the wiring for the wired remote.







My primary concern, of course, is whether or not the motor is safe to wire up and test. I guess that leads me to my first question, how would I go about testing the motor?

I've attempted disassembling the hoist, but haven't gotten much further than the two end plates/caps. I would like to get to the actual chain gears and inspect those, and make sure they aren't contaminated and rusted out. I do believe it still has some oil in the gear box, but really need to get the halves apart to really see what I am dealing with.

Any suggestions on proceeding?

 

[pcmeiners]

You could test the ohms of the motor and any power lead to ground connections, that would be a decent indicator if the motor is compromised.
I had two hoist get visited by Sandy, 1 ton and a 2 ton Budget, both were under salt water for 2 weeks, both looked better then yours once opened, both required too many parts to repair.
Be careful if you start purchasing parts, any hoist part is expensive. Doubt you can find much literature except for a parts diagram.

 

[Jason280]

You could test the ohms of the motor and any power lead to ground connections, that would be a decent indicator if the motor is compromised.

Excuse my ignorance, but could you explain this a little better?

 

[pcmeiners]

With Ohms law, if you know the operating voltage and amperage, you can figure out the impedance/resistance the motor field winding should have ( sometimes manufacturers will show motor ohm reading in their literature). Once you have the resistance, you take an Ohm reading of the motor field coil (s), if the resistance is much lower or almost none, you have shorting either to another part of the field wire or to ground, much higher you have a wire break or wire is compromised as in corrosion or a bad connection .
Somewhat lower resistance, but not close to 0 Ohms, leakage . For the ohm reading to be of use, you need to have no capacitors or electronic in the circuit. Motor field coil impedance/resistance varies slightly due to variations in manufacturing and temperature and meter calibration, so if you ohm reading is off very slightly that is ok eg your supposed to get 4.2 ohm and you get 4.18, that is OK.



https://www.watlow.com/reference/tools/ohmslaw.cfm

http://hyperphysics.phy-astr.gsu.edu/hbase/electric/acohml.html

 

[z28dude38058]

It appears you have a 3 phase motor due to no start capacitor and a dual (reversing) motor starter. That would require an inverter or vfd to drive it on single phase home service. Things to consider


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[Jason280]

 

[Jason280]

I think its single phase...

 

[930dreamer]

Looks like a perfect candidate for dry ice blasting.

 

[Evilelroy]

Maybe you can get a manual for it cm Columbus McKinnon bought coffing a while back they should be able to provide one might be online to print off even.

 

[turfgnome]

Looks like a perfect candidate for dry ice blasting.

Wouldnt it be cheaper to buy a new hoist then a dry ice blaster? But it looks like a cool toy.

 

[Indexmill]

That hoist sure looks toasty.

Even if the motor works, which it probably does, you are looking at alot of work cleaning it up and verifying all of the wiring.

If you really need it, or just loving restoring stuff like I do, then go for it. Otherwise, carefully consider everything before you start.