Electric motor on planer quits running after 1 minute

[mtcowley]

Hello- I have a 50 year old Planer that was my fathers. I had it stored in a basement for the last 10 years. it worked fine then but now it will only run for about 1 minute or less and it cuts off. It will restart after about 5 minutes but does the same thing again. If I take the belts off so there is no load, it continues to run without any problems. I changed the run capacitor and it still does the same thing. The motor says it is to be run 115 volts and not less than a 30 amp breaker. I wired the receptacle myself using a 30 amp breaker and then used orange #10 wire to run to receptacle. The cord on the planer motor is 14/3 and is in good shape but i was surprised it was not #10 wire ? This is original cord as far as I know. Any thoughts on why it is doing this?

 

[DJL33B]

The 14/3 cord may be a problem, but I would start with flushing the bearings with fresh oil. Wood dust plus old oil equals sludge that could increase the mechanical load.

 

[Minder]

If it runs for 5 mins and re-starts after a wait, it sounds like it has a thermal sensor, often embedded in the winding's.
A ammeter would be useful in order to check the loading or reason for the apparent over-current.
M.

 

[Bluejets]

but now it will only run for about 1 minute or less and it cuts off

As Minder says, and depending on the motor type, it could be the centrifugal start switch sticking.
It's a mechanical device so follows your saying it was ok but not now after 10 years.
This switch connects the start winding during startup and if it stays in circuit for too long (normal switch off is when motor gets to around 2/3 full speed) then the thermal overload will operate. It then takes your quoted 5 minutes to cool down. Some require manual reset of this overload button.
You should show a photo of the motor nameplate .
Basics of a centrifugal switch here....

Just be aware some motors do not disassemble the same way and you can actually damage the switchgear if not disassembled in the correct manner.

 

[mtcowley]

Thanks for your thoughts. I am attaching a picture of the motor nameplate. Not sure i am up to dissembling the motor but it is of no use now so I guess I will attempt it to see if I can reset the centrifugal start switch..

 

[mtcowley]

One more question.. How do I get the belt pulley off the shaft? Any tricks or special tools.? I took out the two allen screws but the pulley seems to be frozen in place.

 

[Minder]

Gear puller is needed,
M.

 

[Bluejets]

The pulley is normally on the opposite end of the motor to the switch and normally does not have to be removed.
However.........
I've seen many pulleys destroyed by using pullers such as M shows if the tangs cannot get right in near the shaft at the rear side of the pulley.
People tend to wrap the tongs around the pulley vee section and the first thing to let go is the alloy.
In that instance it is better to use the bearing puller either over a press or in conjunction with the additional puller parts.

BTW..one does not ......"see if I can reset the centrifugal start switch."
If it is the thermal overload that has tripped, and it is the resettable type with the red button, then after a cool down period, a hard press will reset that. If it is an internal overload similar but it auto resets.

The centrifugal switch gets jammed because of dust and crud sticking the mechanism. Best to clean and leave it completely dry, no lubricant.

 

[mtcowley]

Thank you. It sounds like I do not have to take the pulley off. I have one more question though. In my original post, I mentioned that if there is no load on the motor, it will run for at least 5 minutes for that is how long I tested it for. Does that not mean that the centrifugal switch is working?

 

[Bluejets]

Possibly but I doubt it.
It is not difficult to determine if the switch is working ( mechanically) or not.
There is a definite click which can be heard as the motor increases to around 2/3 full speed at startup and again at around 1/4 speed or lower when shut down.
All this is an assumption really as you still have not provided and motor details or photos.

 

[Martaine2005]

Sounds like the motor is fine.
When the belt is off the drum, the motor works.
Can you spin the drum by hand easily?. It should spin freely. If it feels ‘grinding’ or sticky, the bearings need lubricating or replacement.
Oil the bearings, fit the belt and spin it until it frees up.
It should work fine after.

Martin

 

[73's de Edd]

Sir mtcowley . . . . . . . .

As per your . . . .
Does that not mean that the centrifugal switch is working?
Undoubtedly all is well with the units contacting actions of the centrifugal switch.
Since if it is not contacting, at power turn on the motor will just sit there with a loud BUZZZZZ / HUMMMMMMMM.
On my table saw , it has a 3/4 hp @ 3400 RPM motor that has a pulley of ~2 3/4 in dia that then feeds a VEE belt to a
1 in pully on my blades drive shaft. Now with a 60 tooth carbide blade and whipping along at ~7000 RPM.
Don't tell me that I dont get anything less than a glass smooth cut.
HOWEVER . . . . at times ultra fine micro saw dust works down into that cent sw contacts and the the HUMMMMMM at turn on.

Typically being in a rush . . . . . I just drop the belt aside and wrap a cotton / poly venetian cord around the motor pulley and
pull to give a fast spin and a turn on of the motor switch . . . . .on the road again . . . .

Then the belt is eased back on the motor pulley as I rock the motor forward.
Why dont you experiment with changing the load imparted upon the motor, IF you happen to have a tiltable motor, such as I do .
To see if loading is a problem . . . . .plus do the planer blades spin freely ?

73's de Edd . . . . .

I asked my wife what she wanted for her birthday . She told me "Nothing would make her happier than a diamond necklace"
So, thats exactly what I did . . . . I bought her nothing.

 

[Bluejets]

Sounds like the motor is fine.
When the belt is off the drum, the motor works.
Can you spin the drum by hand easily?. It should spin freely. If it feels ‘grinding’ or sticky, the bearings need lubricating or replacement.
Oil the bearings, fit the belt and spin it until it frees up.
It should work fine after.

Martin

I doubt it....op said it trips the o/l frequently after less than 1 minute on load.
Op does not seem to want to supply detail I asked for so can't do much more.
As it was ok when it was stored, and it's a open frame, hornets probably been in and built a mud nest in amongst the cent. sw.

 

[mtcowley]

Sorry but it was not that I did not want to send a picture but I got a new computer with Windows 10 and it has been a nightmare for me and photos. I just finally just figured out(with my wife's help) how to get pics off the phone. So I am attaching the name plate off the motor and a picture of the motor. I tried to get both the pullet off or the plastic fan with no success. I know I can get a device to pull the pulley off and I will if need be. Thanks for all the help and if anyone can tell me a simple way to take this motor apart, I would appreciate it.
Opps- So when I try to upload a file I get a message "There was a problem uploading your file." What is this all about?

 

[bertus]

Hello,

When the filesize is to big, you will get an error message.
When you keep the filesize at about 300 k, you will be fine.
You can reduce the filesize with a paintlike program.

Bertus

 

[bushtech]

File probably too big. Aim for something in Kb range, not Mb

 

[mtcowley]

Here you go.

 

[Bluejets]

Good job on the photos...excellent.

Link to your model for an exploded view.
https://www.searspartsdirect.com/model/1zztsstp5c-000247/craftsman-11312310-power-tool-parts

Appears to be a sealed motor so I withdraw my comment on hornets nest being a possible culprit.
Most times this would eliminate rubbish in the switch but it still could be damaged in some way.
It could be a fault in the motor windings, however, it still points to the centrifugal switch sticking or malfunctioning in some way given you say it was fine when originally stored away.

Centrifugal mechanical mechanism (part No.2) and the switch plate (part No. 21).
No requirement as said previously, to remove the pulley.

Removal of the fan without damage can be a right pain.
It really requires the right tool to get in behind the centre of the boss near the shaft.
My workshop, and more than likely a decent local electrical workshop to you, should have the necessary know how and tooling.

You say you replaced the capacitor, so was it the right size and type..??
Need to verify before you go ripping the motor apart.
Do you hear any clicking of the centrifugal switch as the motor spins up and down...only needs to be powered on for a couple of seconds.

 

[73's de Edd]

Sir mtcowley . . . . .

I, also would not be so eager to get inside of that motor housing proper, until further checking out the boxed area which the power cord enters and also inside the cover over the capacitor (s) at the top.
Is there just one capacitor(s) being within that unit, or is it having two units ( start and run) being built within one capacitor casing ?
And what is/ are the capacitor(s) values and voltage ratings .

Unless a capacitor (s) is open , you should be getting a LOUD humm just as soon as AC power is turned on to the unit.

This is one typical motor wiring diagram

If the run cap has decreased in capacitance SIGNIFICANTLY the motor would not run up to par or else, be weak in torque.
If the start cap has failed the unit would not start up from a standstill; same situation with an inoperative start / centrifiugal switch.
Then the motor will make a loud HUMMMMMM until the motor shaft is physically rotated fast enough / in the correct direcction / for the weaker magnetic field of the run winding to take over .

Here is a situation of having a non contacting centrifugal switch . . . . note the loud HUMMMMMM on initial AC power up. And NO movement of the motor pulley.
(HIS " cement powder " . . . . .was being MY ultrafine sawdust ))

73's de Edd . . . . .


I'm certainly glad I know sign language . . . . . . it's pretty handy.
.

 

[Harald Kapp]

I suggest you go back to @Bluejets post #4.
As the motor starts spinning when turned on, it seems that the start capacitor is in the circuit and doing its job. However, if is not released after spin-up of the motor, the start winding will continuously dissipate too much power. This in turn may cause overheating and activation of a thermal protection as @Minder mentioned in post #3.