Electric Motor Repair

[Charlie]

Hi All:

I left my Caulder Bible at the boat and need to track down a problem with the motor for my windlass (which is at home) Does anyone know a good website that will show me how to troubleshoot a DC Motor? Or a thread?

[Pblais]

Some of this can be easy.

Check the breaker. You may also have a safty heat activated breaker that can be reset. It is set so any overload will heat up the breaker and then open it. It is supposed to prevent you from burning up the motor should your winch jam. Resetting that breaker will fix evrything.

If you have a volt meter then you can power it on and look for voltage. If you have deck foot switches they can be a good source for problems. The switches operate a solinoid that actually applies power to the winch. Foot switches can leak water and short ot thus killing the winch.

Look for burnt wires. If the motor was overloaded and the breaker failed it usually burns out the motor. It's usually very easy to tell. Trace back the wires as best you can and look for chafe or other problems.

Odds are the motor is not fried and if it is not it should work if it has power. Getting power would be the first thing to troubleshoot.

[Charlie]

Thanks Paul:

I have the motor disconnected from the windlass and I am using a battery charger (car battery) as power. The motor won't move. I don't know if it the connection from the charger or the motor itself. I think it is time to buy a second copy of the caluder bible.

[Charlie]

Ok I just realized you can't test a windlass motor w/o a solinoid(sp?). I guess I'll put it back together and take it down to the boat.

[LtBrett]

You don't need a solenoid, but you might need a battery or jumper cables. Not sure if an automotive charger will give you the amps you need. Plus it might have a "brain" and be looking for voltage. If the motor doesn't spin when connected to a battery, it is likely bad.

Brett

[DeepFrz]

You haven't given us much information Charlie, but here goes.
1. If you are getting 12 volts (nominal) out of your charger it should turn the motor.

2. Can you turn the rotor by hand? If not it is probably bearings that are seized. Possibly a permanent magnet has broken and jammed.

3. Take it apart and check that the brushes and connections to them are good and that they are free to move in the holders.

4. Check the wiring.

5. Check here for info.
http://electronics.howstuffworks.com/motor1.htm

6. If you haven't found the problem yet, take it to an electrical motor repair shop...

Good, luck, hope this helps.

[Charlie]

When I hook it up I get a humming sound but it does not spin. I took it apart and the brushes seems to be fine. I had this repaired a few months ago and it has worked well. I was just trying to see if the windlass itself was working right. The charger has a setting that will give 50 amps. I've only tried 10 amps so far. It seems to me that I read somewhere that you need a solenoid to increase the power to the motor to get it to start.

[DeepFrz]

If you can take an end cap off without removing the brushes, try an ohmmeter across the two brushes. You should read close to 0 ohms. It could be an electromagnet rather than a permanent magnet type and if so you could try an ohmmeter across the magnet leads as well. When you do that slip some paper under one of the brushes to isolate the rotor.

The vibration means it is trying to start. Is it a permanent magnet type? If so maybe they have lost their magnetism or are broken. If electromagnetic stator then maybe the stator needs rewinding.

Did it work for a while after repair? Maybe the shop will check it out under warranty?

They are pretty simple devices unless they are the DC brush-less type, which yours isn't.

Edit: The solenoid is only so you don't have 100 amps running through the control cct. Just like the solenoid on the starter motor. Try the charger on the 50 amp setting.

[DeepFrz]

Starting motor does not operate when battery cable is directly connected with terminal stud of connector (contact) blade
a - Brushes sticking
b - Brushes worn
c - Weak spring tension. Brushes do not make contact
d - Commutator dirty
e - Commutator rough, pitted, or burned
f - Armature or Field coils defective

a - Clean brushes and guides of brush holders
b - Replace brushes
c - Replace springs
d - Clean commutator
e - Recondition starting motor
f - Overhaul starting motor

This should read across, a to a etc. It didn't copy well.

[Charlie]

Thaks DF:

I will look into the list you posted today. I did take it apart yesterday and looked at the parts. It was a bit dirty. I will bring it down to the place that did the work and have them test it on Monday.

[never monday]

Charlie,
what brand is the windlass?

[Charlie]

Hi Pat:

It is a nilsson windlass.

[never monday]

Originally Posted by Charlie

Hi Pat:

It is a nilsson windlass.

I haven't been in one of those. Lewmar uses a creative L & R thread to mount the drive gear and lock nut. I've had the drive gear bind on the housing. It was so tight the motor wouldn't turn.
From the sound you described. I think the electrons are flowing in the coils. And, It sounds like a mechanical lock up.

[Charlie]

Thanks Pat:

I'm going to take it to the guys who did the rebuild on the motor and see if they can test it. It was working fine. The thing is 23 years old and may just need to be replaced but I'll give it one more shot.

[DeepFrz]

How did this turn out, Charlie?