Motor Problem; won't work under load

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brother said:
Reall?? Even at the Panel?? there may be more than one issue at hand, (gears,etc) but i still think there is still also an electrical problem. you should not be getting only 103 volts at the panel.
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True enough, I would expect around 110 volts.
 
Problem Solved

Problem Solved

The lift is now working. I explain below:

First, I think there may have been some confusion from some information. The VD was not 2-3V @ the sub-panel, but 2-3V less than at the motor. So if I was dropping 20V @ the motor, I was dropping 18V @ the sub:

Anyway, the guys at the motor shop hadn't gotten around to checking it by lunch, and the owner wanted to try this pulley idea, so I picked it up and took it back to the site. The remote manufacturer recommended going 240v. The transformer in the remote box was capable of 240v, so I rewired that and the motor for 240v. Now @ 120v I had 15% drop. I started the lift @ 240V and once it reached the boat, I got the same thing only less severe. The motor was stalling and VD was 7%. Yes, I got the "oh crap" feeling.

To answer a question from earlier, yes the gearbox was well lubricated, however, an inspection of the bearings on the rollers revealed that not a drop of grease had been applied.

We greased the rollers and it now runs like a champ w/ VD @ 2-3%. Tada.

I feel like an idiot. But thanks for all the suggestions!
 
Brant,

Did you do anything about GFCI protection? It came with the lift originally (on the cordset), right? Did the controller have a GFCI donut inside? If so, you need a neutral to make it work properly (at least on the ones I've seen).
 
this controller did not come w/ its own GFI protection. I had a GFCI recep installed ahead of this controller @ 120V. This is a good question. There's no longer a neutral in this equation.
 
i looked it up a few minutes ago. the code only specifies that 120v 15-20A receps that serve a boat hoist have to be GFCI protected. i couldn't find anything referencing a controller though.
 
crossman said:
A change in the 2008 code also requires 240 volt boat hoists to be GFCI protected. Time for a 2-pole GFCI breaker.
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Do 2-pole GFCI breakers work w/o a neutral?
 
Congrats brantmacga. The weekend will go much better without that hanging over you.

Thanks for the post crossman, although carl had the first thought on binding, you were the first to commit to a mechanical problem, I just picked one more prone to install errors.

cows & hawgs? Come on quogue, you're not foolin' anybody, I know cows have no opposable thumbs. This whole story sounds fishy to me.
 
mivey said:
Congrats brantmacga. The weekend will go much better without that hanging over you.

Thanks for the post crossman, although carl had the first thought on binding, you were the first to commit to a mechanical problem, I just picked one more prone to install errors.

cows & hawgs? Come on quogue, you're not foolin' anybody, I know cows have no opposable thumbs. This whole story sounds fishy to me.
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I can speak Hawg I live in the barn with em. The amprobe reading in the 100 amp range would have been the first tipoff now everyone go out and get an amprobe!!
 
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brantmacga said:
The lift is now working. I explain below:

First, I think there may have been some confusion from some information. The VD was not 2-3V @ the sub-panel, but 2-3V less than at the motor. So if I was dropping 20V @ the motor, I was dropping 18V @ the sub:!
Click to expand...
To keep it simple, could you have just said '' I get 103 volts at the sub panel when the motor is running, and 100 volts at the motor?? ;)

brantmacga said:
Anyway, the guys at the motor shop hadn't gotten around to checking it by lunch, and the owner wanted to try this pulley idea, so I picked it up and took it back to the site. The remote manufacturer recommended going 240v. The transformer in the remote box was capable of 240v, so I rewired that and the motor for 240v. Now @ 120v I had 15% drop. I started the lift @ 240V and once it reached the boat, I got the same thing only less severe. The motor was stalling and VD was 7%. Yes, I got the "oh crap" feeling.

To answer a question from earlier, yes the gearbox was well lubricated, however, an inspection of the bearings on the rollers revealed that not a drop of grease had been applied.

We greased the rollers and it now runs like a champ w/ VD @ 2-3%. Tada.

I feel like an idiot. But thanks for all the suggestions!
Click to expand...

Well i learned something new today. Didnt know that much 'resistance' could cause a voltage drop of that much all the way back at the panel. Help me with my Voltage Drop formula here,

VD=(2K X L X I)/cm
K= 12.9 for Copper at 75 degrees Celsius (resistance in Ohms of one circular mil foot of conductor)
L= One way length of Circuit
I= amps
Cm= circular mills of conductor

Seeing how there was no 'grease' on the bearings, the 'resistance' built up pretty good, so i can see that happen from my 'Ugly's referrence' book for the forumula for voltage drop.
;)
 
brantmacga said:
How does it know to measure current difference between L1 and L2 as opposed to L1-neutral and L2-neutral?
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It is like a thermos it keeps hot things hot and cold things cold. How does it know?? What goes out must come back it has a neutral pigly wigly tail that you have to hook up to the neutral bar and the load if it doesnt have a neutral no hook up but if it has a neutral you have to land it on the breaker.
 
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