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ADDICTED2WAKE

What's wrong with my hoist?

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ADDICTED2WAKE

I have an older cantilever style 4000# hoist but with cable, pulleys, and motor all new in the last 2-4 yrs.

I have a vride (3500# w/ gas and gear).

The last 2 summers the motor has struggled. If the boat was out of the water and I wanted to raise it more from a stop, the motor would just hum (no movement). I'd drop it for a second, then try to raise it and it would move up but it was still struggling. I replaced one seized pulley (which was only 1 yr old). I do have a 100' extension cord to the hoist but the voltage to the motor is 120.

Could all my pulleys be bad already after 4 yrs of use? Something is not right but I'm not sure what else to check.

And the newer motor is 1/2 hp more than original.

Thoughts? Anyone else have this before?

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FastFreddy

I'd put money on the 100ft extension being the problem. It is likely causing alot of resistance. Make sure you use at a minimum a 12ga extension and I would actually reccomend a 10ga or larger for the length you have there.

A good way to check is to check the temperature of the extension. If it gets warm at all during the lifting of the boat that is definetely the problem and could be dangerous.

Edited by fredberg1414

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Pistol Pete

How does the lift operate with no boat on it?

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ADDICTED2WAKE

If I'm still getting 120v to the motor, does that negate the concern for the resistance of the extension cord? Sorry, not "electrically inclined".

Pete, the hoist lifts fine without a boat on it...

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GreenMan

Is that 120 V measured with the motor running? If not, you have to check that. There is no value at all in measuring the voltage at the cord extension socket with no load (current flowing) on the cord...

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Pistol Pete

You will always show ~120V at the motor.

what we need to figure out is voltage drop along the run of that extension cord. what we really need to know is how many amps. it's pulling.

Is there any way for you to substitute out the extension cable for a generator right at the motor?

Or, buy one of these?

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FastFreddy

You said the motor is now bigger. Bigger motor =more current required.

What is the gauge aka ga of the extension cord?

What is the total hp or even better wattage of the motor?

If you start lifting the boat and dont stop does it work properly?

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GreenMan

You will always show ~120V at the motor.

what we need to figure out is voltage drop along the run of that extension cord. what we really need to know is how many amps. it's pulling.

Is there any way for you to substitute out the extension cable for a generator right at the motor?

Or, buy one of these?

Pete, with respect, the comment that 'You will always show ~120V at the motor' is not necessarily correct. If there is 120 volts at the source (a power socket or whatever the cord is plugged into) and there is, say, 20 volts drop across a skinny extension cord with the motor running, then there will be only 100 volts measured at the motor while running.

Knowing the amps is kind of irrelevant. The motor will pull whatever amps it can and needs given it's load and terminal voltage conditions. It's up to the user to ensure that sufficient size conductors of low enough resistance are provided to ensure minimum/acceptable voltage drop.

Measure the voltage at the source power outlet with the motor running. Really easy if the lead is plugged into a double power outlet ar a double adaptor type arrangement. Just measure the voltage at the 'spare' outlet while the motor is running. Presumably it will be close to 120 volts. If not, there's the first problem... Now come up with a way of measuring the voltage at the motor terminals or the end of the extension cord while it is running. The second measurement WILL be lower than the first - (I think the single phase voltage in USA is 120 volts?) You won't want to see much lower than 110 at the motor. My guess is that it will be significantly less than 120 volts and therefore a problem.

In the US you have half the voltage we have in Australia (240) so you require wires of double the size we have to do the same work (half the voltage means double the amps to do the same job). You would need a heafty cord to cope with supplying the significant starting current of the motor without also showing significant voltage drop. My tip is that vd will be the culprit somewhere in the electrical supply. Some of it may also be occuring 'upstream' of whatever his cord is plugged into.

Hopefully ADDICTED has the means to safely make some measurements and can report back...

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coyote055

I've been an industrial electrician for 15 years and, if I had to bet on a cause, I'd say that the cord is the problem. Voltage drop, current draw, and wire size are all related. Look at the name plate on the motor. It should give you the full load amps at 120 volts (and maybe 240 volts if it's a multi-voltage motor). As Pete suggested, rent a generator that will handle the 120 volt motor amperage, and plug your hoist in with a short cord ( the shorter the better) that will also handle the motor amps. As for a permanent solution, if you have a multi-voltage motor, I would suggest going to a 240 volt outlet, rewire the motor for 240 (it's not that hard), and size your cord so that the voltage drop stays within 3 percent of household voltage. If your motor is a single voltage motor, your only option is to upsize your cord (and maybe install a dedicated circuit for your hoist). In any case, voltage drop should be no more than 3 percent. The voltage drop calculation can be found here: http://www.elec-toolbox.com/Formulas/Useful/formulas.htm . good luck.

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ADDICTED2WAKE

Thanks all, really appreciate the feedback. I'm traveling for work this week but will check next week when I return.

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Pistol Pete

GM.

Thanks for pointing out what I didn't say clearly.

When I said you will always see 120v at the motor, I meant with no load. My bad.

I forgot to mention any drop while the motor is running.

And, I don't have any experience with 240v systems but, between you and Coyote, I think A2W is in good hands.

Cheers.

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GreenMan

GM.

Thanks for pointing out what I didn't say clearly.

When I said you will always see 120v at the motor, I meant with no load. My bad.

I forgot to mention any drop while the motor is running.

And, I don't have any experience with 240v systems but, between you and Coyote, I think A2W is in good hands.

Cheers.

Hey, no worries, Pete.

That stuff is 'up my alley' with ~40 years experience as a sparky, albeit almost burnt out now!

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ADDICTED2WAKE

Just a quick update, I did find the rearmost pulleys (the ones that sit at water level 90% of the time) were basically seized. Unfortunately they are 3 yrs old so I'm not pumped about that but at least it's easy to replace.<br />And I'm going to run power under ground to the sea wall and then a heavy gauge extension cord from there...<br />Hoist goes in Sunday and bu will go in within ~2 wks after that (need to tint windshield and install new stereo first)...

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fastmcars

Shorestation won't sell a plug in, 120v, lift anymore. They were tired of replacing motors under warranty due to small( gauge of wire) frying the electric motor. Now they run off of batteries with a trickle charger or solar charger. My hydraulic 10,000lb lift runs just fine off of two batteries hooked in series(24v). I didn't really like the concept of this setup at first, but it has worked flawlessly for 4 years on the same batteries. I have a mig welder that I use once and a while and had to pull new wire to use it in a garage. The welder would work, but it would't penetrate the metal for a good weld.

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