2 ton electric chain hoist problem

[blazemaster83]

I snagged this hoist today for the price of driving to pick it up. I originally went to go pick up some old plastic fixtures from a machine shop just to get the material (which was a lot of useable delrin, uhmw and polypro) and as I finished loading the plastic in my truck they asked if I was interested in this hoist also. They had a small 1 ton gantry and this hoist was way too big. He mentioned that the last time it was used, it would not go down, only up.

Once I got the thing home and looked at it closer, it has a 3 phase motor but only a 110v plug. I used my old manual hoist to lift it up and sure enough, it goes up but not down. The chain is not twisted which was my first thought. I took the electrical cover off and both relays seem to work (up and down) which makes me think the brake is not releasing. The thing looks brand new so I doubt its broken. The shop it came from didn't have anything to lift 4k lbs from so I don't think it was abused.

Anyone experienced something like this with an electric hoist? There is no brand name on the hoist which makes me think it's an import. I did hang about 500lbs on it to see if that would make it move but no dice. I guess tomorrow I will pick up something a little heavier and see if it will pop loose before I tear into it. I believe I need to drain oil from the gearbox and take it completely apart to get to the brake, so I'd like to do that as a last resort.

 

[Dustball]

You need three phases to run it.

 

[blazemaster83]

It wouldn't work at all if 3 phase was needed. It still goes up, just not down. Inside the cover there is a small 110v converter, I will take another pic tomorrow.

 

[jkeyser14]

You might need to put a lot more than 500 lbs on it. Hoists have internal brakes and they can occasionally get wedged into place which only allows them to move up. To release the brake you need to raise a heavy load a couple of inches, then reverse directions and try to go down.

 

[aussieblake]

It wouldn't work at all if 3 phase was needed. It still goes up, just not down. Inside the cover there is a small 110v converter, I will take another pic tomorrow.

Do you think the 110 volt power is for the controls only?

 

[infinkc]

well if it works on 110 then its not 3phase, just labelled wrong. i would open up the control and test the down switch, could be easy as that. I would think it is just reversing the motor polarity. to either go up or down.

 

[Beans]

If it is a 3 phase motor you will have a reversing contactor inside of it or something else doing that job.
AC 3 phase: change rotation of motor by swapping any 2 leads.
DC: changes polarity for rotation change

 

[matt_i]

You might need to put a lot more than 500 lbs on it. Hoists have internal brakes and they can occasionally get wedged into place which only allows them to move up. To release the brake you need to raise a heavy load a couple of inches, then reverse directions and try to go down.

It looks to me like a knockoff of a Harrington hoist.

I don't agree with the above. If the brake works, it locks the pocketed chain-sheave rotation via a spring-engagement-lock/electric-solenoid-release. If the brake pads got jammed in either direction, then the solenoid could not overcome and it would be locked forevermore.

There are some pieces of info missing on some of the tags/labels. I see the 3ph tag riveted to the motor, which would tell me that the basic assumption is that the motor is 3ph. Check the number of wires going into each of the double contactors, if there are "3 in, 3 out" then that checks out with the riveted tag and single phase will never make it work correctly. Its possible that the motor could indeed move under "phase loss half voltage" but get it under load and only the full design voltage and all phases present will develop the torque needed to lift a load.

I would think its a reasonable candidate for an RPC rotary phase converter but the control voltage can't involve the generated leg, it can only be sourced from "utility supplied phases" otherwise mad relay chatter will result.

 

[TurnipTruck]

During an outage, our 3-phase shop had to be temporarily powered by a generator. A contractor needed to continue using the 3-phase hoist, so we hooked that up, but must have gotten the phases wrong. He carried on using it, just had to make a mental note that up is down and down is up. Worked fine until he got all the way up using the down button and it wouldn’t unlock the two-block switch. We had to swap phases again just for the hoist to apparently put the Down on the same phase as the two-block.

 

[marinusdees]

This hoist has an electromagnetic brake so if it is stuck (highly unlikely) it wouldn't go either direction. It would run on a 120 volt plug IF it was fed three phase, one each thru each wire, bad business, can not be grounded. If you are willing to ask for some advice, drive to north Puyallup (take it with you) to All Electric Motor Service. Mike Thayer is the owner. He's a straight shooter, will answer your questions.
PS I have four electric chain hoists, all salvaged from Mike. One is three phase, I feed it with a homemade rotary phase converter. I don't experience mad relay chatter. All mounted on trolleys, on I-beams. If you want to see them, PM me, I'll send you my address. I'm retired, mostly home. I'll be in Lacey today, have grandsons to see in Olympia.

 

[marinusdees]

PS The brake is not in the gear box. If it is not leaking and there is oil in it, I'd leave it alone. If it is empty, I'd fill it and wait to see if it leaks. This hoist is cosmetically in good shape. Should run if fed the correct current. It's interesting that the voltage name tag rating is so obscure. Not sure what that's all about.
I wanna see what that 110 volt "converter" looks like.

 

[Dustball]

I'm guessing it's the SHK-A-020-2S hoist which seems to be a common part number across multiple overseas manufacturers.

http://www.tbmhoist.com/product-detail.php?id=95

380v-415v/50Hz/3PH standard
Single phase optional

What is the voltage stamped on the nameplate? It's unreadable in the photo but kind of looks like 110v.

 

[blazemaster83]

Here is inside the case. After looking closer at the nameplate, it does say 110v. It's a light mark. Not sure how it could be 3 phase and 110v. I tried picking up a table I have that weighs around 1k lbs., still worked up, but no down movement. I did try to move it up a few inches first. The contactors definitely both click and move when the up or down button is pushed.

 

[marinusdees]

That "110 volt converter may be a Sinpac. Forget the technical name, that's a brand name. You can call Mike at All Electric if you don't want to drive. If he's there, he'll talk with you. No charge for advice, and it's good.
That thing looks to be all original, not tampered with. Virtually new. Just a guess.

 

[matt_i]

Here's what I see. I could be wrong.

Does the "SO" black cord at top with black and white attach to the incoming power?

And do the two blue wires below that goto the motor winding?

Those pairs connect "straight thru" when the left contactor is energized LeftL1-T1 and L3-T3)

If I follow the red wires at top, From Left-L1 wire seems to goto Right-L1.

From Left-L3 wire seems to goto Right-L3.

On the bottom side, the blue wires are connected to Left T1 and Left T3.

Right T3 hooks to Left T3.

Right T1 hooks to Left T2 but is also jumpered to Right T1.

So essentially there's no reversing of the input AC sine wave relative to the blue leads no matter which contactor is energized.... (Left L1- Right L1- Left T2- Left T1 and Left L3-Right L3-Right T3-Left T3)

A potential way to fix this is to rearrange the top red jumper wires.

Go from Left L1 to Right L3 with a jumper eliminating the former Left L1 to Right L1.

Go from Left L3 to Right L1 with a jumper, eliminating the former Left L3 to Right L3.

This strategy reverses the direction of the sine wave on the R vs L contactor hit.

 

[blazemaster83]

I switched those jumpers around like you mentioned and it did the same as before. Will lift the load, but won't go down even though the "down" contactor clicks.

 

[manwithtools]

Have you checked for continuity across the contacts when the down contactor "clicks"? This might take two people, one to press the down button on the pendant and one to check continuity.

 

[marinusdees]

The hoist has two limit switches which stop the motor when the chain reaches either extremity. If it goes in one direction, it has the ability to run in the other, if fed the proper current. The limit switches are similar in appearance to the limit switches in garage door openers. Typically, some sort of threaded rod which turns when the motor is running, with a switch which opens when a follower on the rod reaches it. Sounds to me like the limit switch for the direction it won't go is either defective or has a loose connection.

 

[blazemaster83]

I did check and it gets power through the contactors, and the limit switches looks fine on the surface. I may take it up to puyallup if I have time, I just don't have a ton of extra cash to spend on this at the moment. Thanks for the replies.

 

[racer-john]

Please keep us posted on what you find out.

 

[marinusdees]

I don't think you're looking at a lot of cash. If you want to bring it to my place, PM me, I work for free. And, Mike is 5 minutes away and a good enough friend I can ask for advice, he won't mind. I can't imagine, givien the cosmetics, that there is anything seriously wrong with that hoist.
Now, I'll shut up.

 

[manwithtools]

I don't think you're looking at a lot of cash. If you want to bring it to my place, PM me, I work for free. And, Mike is 5 minutes away and a good enough friend I can ask for advice, he won't mind. I can't imagine, givien the cosmetics, that there is anything seriously wrong with that hoist.
Now, I'll shut up.

Well, there you go, and done in true GJ family spirit! You just can't beat that offer!

Now, I'll shut up!

 

[blazemaster83]

Talked with Marinusdees and he seemed to think it was the centrifugal switch, which is the little black box. When I looked up that exact switch, I can only end up finding the 220v model, it ships from china for $34 and who knows how long to ship. There is also a nicer unit Stearns Sinpac instant reversing switch for around $120. I will have to put this on the backburner for now unless I can find a cheaper option, I just don't have the cash right now for the sinpac and I don't really want to order the 220v from china.

I was hoping I could switch some leads around and get it to lower the hoist but after messing with it for about 40 mins, I can still only get it to raise. Electricity just isn't my strong suit.

Anybody happen to have a sinpac laying around for less than $120?

 

[matt_i]

This is wortha look.

https://www.americancrane.com/wp-content/uploads/Electric-Chain-Hoist-Wiring-Diagrams-113535-31.pdf

Its a 16 page pdf which is possibly close to your situation. But the main diagram is on page 1. The single phase motor that they use isn't just a 2 wire unit however, it has a winding for fwd and a winding for reverse. Looks like 6 wires if you don't have the thermal overload switch, 8 wires if you do.

As I think was mentioned previously, its important to make sure all 4 poles on each relay are connected "straight thru" with power off (voltmeter and a helper or clamp holding in the relay coil)

After that there's the potential for multiple wires landed on the same screw terminal to be done incorrectly, and have one barely attached or attached via the insulation only.

You get past that and your motor's reverse-winding could have an issue.

 

[marinusdees]

This is wortha look.

https://www.americancrane.com/wp-content/uploads/Electric-Chain-Hoist-Wiring-Diagrams-113535-31.pdf

Its a 16 page pdf which is possibly close to your situation. But the main diagram is on page 1. The single phase motor that they use isn't just a 2 wire unit however, it has a winding for fwd and a winding for reverse. Looks like 6 wires if you don't have the thermal overload switch, 8 wires if you do.

As I think was mentioned previously, its important to make sure all 4 poles on each relay are connected "straight thru" with power off (voltmeter and a helper or clamp holding in the relay coil)

After that there's the potential for multiple wires landed on the same screw terminal to be done incorrectly, and have one barely attached or attached via the insulation only.

You get past that and your motor's reverse-winding could have an issue.

I'd be willing to bet there is one run winding, one start winding, total of four leads from the motor. I'd see if I could source a replacement form China. I gather you are not ion a hurry, saves a lot of money.

 

[marinusdees]

This is wortha look.

https://www.americancrane.com/wp-content/uploads/Electric-Chain-Hoist-Wiring-Diagrams-113535-31.pdf

Its a 16 page pdf which is possibly close to your situation. But the main diagram is on page 1. The single phase motor that they use isn't just a 2 wire unit however, it has a winding for fwd and a winding for reverse. Looks like 6 wires if you don't have the thermal overload switch, 8 wires if you do.

As I think was mentioned previously, its important to make sure all 4 poles on each relay are connected "straight thru" with power off (voltmeter and a helper or clamp holding in the relay coil)

After that there's the potential for multiple wires landed on the same screw terminal to be done incorrectly, and have one barely attached or attached via the insulation only.

You get past that and your motor's reverse-winding could have an issue.

I'd be willing to bet there is one run winding, one start winding, total of four leads from the motor. I'd see if I could source a replacement from China. I gather you are not ion a hurry, saves a lot of money.