Pump vibration. Conductor burnt at breaker outlet.

[Strobos]

My 1 1/2hp Whisperflo pump has been noticeably louder and vibrating for several days. The grand kids have been playing with water balloons and I thought a piece of rubber may have snuck through the filter basket and got stuck in the impeller. I figured I would give it time to work through the impeller before I attempted pump disassembly. This morning I went to clean the pump basket and afterwards the pump would not start. I grabbed my meter and soon I discovered that one of the ac power legs (It's a 220v) was burnt off at the fuse. Now the pool, pool wiring and breakers are 22 years old. The pump and mechanical timer about 7 years old. I am going to fish new wiring. There are now 2 yellow conductors for ac power to the pump, 1 blue for the pool light and ac outlets, a white neutral and a green ground. The 2 pump breakers are 15 amps. I ohmed across the two leads to the motor and I did get a beep with 1.5 ohms resistance indicating a short at the motor or cap. At this point I doubt there is anything stuck in the impeller but I won't know until I open it up.

Before I get started, several questions.

1. Did the motor short cause the wiring to burn through at the breaker or the other way, the old burnt conductor cause unbalanced power to the motor making it vibrate until a short developed.

2. What size conductors are required today for a 1 1/2 hp pump and should I run extra wires for future expansion? Wiring schematics to make sure I comply with code?

3. Should I repair or replace the motor on the 7 year old Whisperflo or get the new variable speed pump which I have been eyeing now.

Thanks for the help

 

[Strobos]

UPDATE:

I just took the cap off. Looks good. No beep, no short.

 

[mas985]

The motor winding's should read 1-2 ohms, that's normal. The capacitor should initially read low resistance and then steadily climb to infinite. Also, you need to short the capacitor terminals before measurement.


If the motor is visibly vibrating, that could be bent motor shaft. If it is just making a lot of noise, then it is more likely to be a bad bearing. Given the burnt the leads, I would lean more to a bad bearing which causes high loads and current draw.

 

[Strobos]

Thanks for the help.
The cap is good also. After shorting the resistance slowly climbed to infinite. There was no visible vibration, just audible vibes and extra pumping noise. Is replacing motor bearings difficult and expensive? Or should I just swap out the whole motor end. Or just get the variable speed pump now and be done with it?

Is it okay to up the wire gauge one step thicker? I assume the builder put the minimum for a 15 amp circuit. The two pump breakers will remain 15 amps but will be replaced with gfi units which I bought previously but never got aound to changing.
I just want to be within code.
Thanks again.

 

[mas985]

Is replacing motor bearings difficult and expensive?

Not expensive nor terribly difficult. It depends on how handy you are. Replacing bearings just requires a bearing puller and there are plenty of tutorials on Youtube so you might have a look at those first to decide if you are up to it.

http://www.youtube.com/watch?v=WX9OJJv9H_o
http://www.youtube.com/watch?v=nrvNZmUPRis

Is it okay to up the wire gauge one step thicker?

Was the wire smaller than 14 gauge? The reason the wires burned, is probably because the load was too high and for some reason the breaker did not trip. If you are going to replace the breakers anyway, that should solve the problem. But the only issue with going with thicker wire is confusion by someone else so if you go with 12 gauge, you might consider going with 20 amp breakers too as long as there are no other 14 gauge wires connected to the same breaker.

 

[Strobos]

The wires looks like 14 gauge. I will know tomorrow when I cut a piece off and go match it. There are 5 conducters in that conduit all the same size. Regardless I will keep it 14 gauge since I already paid a lot for the 15 amp gfi breakers. I bought them months ago and I doubt the supplier would take them back now. They were a special order.
Thanks again.