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Westy sparking on startup.  Rate Topic 
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 Posted: Sat Feb 20th, 2021 05:41 pm
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Bob Bosco
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I just picked up a 162628 non-oscillating brass blade brass cage Westy.  It runs great on all three speeds, very quiet. Problem is on start up I see that it’s arcing or shorting out in the front a little bit and then goes away as it runs. Looks a little oily in there any suggestions on how to fix that do I have to take the whole thing apart?  Remove Stator which I can’t do?

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 Posted: Sat Feb 20th, 2021 06:21 pm
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Elliot Segal
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Bob, Here's some background to consider. When your motor starts it has inrush current, also referred to as “locked rotor current,” and this is the excessive current flow that happens inside a motor and its conductors during the first few moments after switching on the motor. This current draw is sometimes referred to as “locked rotor current” because the current necessary at startup to begin the rotation of a non-rotating, de-energized motor shaft, is very similar to the extreme current draw experienced for the moments when a motor is overloaded to the point of seizing. In both cases, the current draw is such that is required when the motor is trying to overcome an idle motor shaft.

Modern appliances have devices protecting the motor and its circuitry to withstand this brief, but extreme current spike, while still providing appropriate protection against short-to-ground faults and motor overload conditions.

This can be a fine line to walk.

Motor Inrush Current is a Necessary Overload Condition

So, what is motor inrush-current? When an AC motor is first energized, excessive current is drawn on the circuit supplying the motor, well beyond the current levels specified on the motor nameplate. High resistance is often encountered when starting a motor from a static (idle) position, and excessive current draw is necessary to begin rotation of the motor shaft.



Often, during the initial half-cycle of electrical current flow experienced at motor startup, (Note: A half-cycle in a 60 Hz electrical system equates to 1/120 of a second duration of time) inrush currents reach levels 20 times greater than the normal current levels experienced during the motor’s normal operating speeds. After this initial inrush of current, the motor begins to rotate. At this point the initial starting current subsides, reducing to a level of current equal to 4 – 8 times the normal running current for that motor. This reduced, yet still largely exaggerated current, is sustained only briefly, as the motor quickly reaches full running speed, where current then subsides to its normal operating level.



Inrush Current and the Motor Components

When considering inrush current, it helps to understand what is going on inside the AC induction motor when we first energize it. We know the stator windings are energized instantly upon power up. The alternating current (AC) supplied to this winding, produces an alternating magnetic-field, and then induces that field into the rotor.



The difference in the magnetic fields between the stator winding (stationary copper winding group within the motor) and the rotor winding (rotating shaft winding) is the biggest contributor to the initial inrush current experienced at startup. Once the rotor starts to rotate and then catches up with the stator’s magnetic field, the difference between the two fields is diminished and inrush current drops proportionally.

So we know the standard AC induction motor always experiences some degree of slip; the two magnetic fields never synchronize entirely, as the rotor always lags the stator winding field to some degree. This motor “slip” is specified as percent of slip, and the final torque that is delivered from the motor shaft is the result of the magnetic force induced to the motor shaft, minus that slip.

SO what's this all got to do with your fan? The initial start up and arcing COULD BE a mechanical resistance to the rotor turning, there could also be debris inside the motor between the stator and rotor, etc. If this fan has been sitting around for a long time in adverse environment (dirt, dust, grease etc) chances are, it's dirty as all get out. You should at least carefully remove the cage and blade, open the motor housing nd remove the rotor only -- -just the rotor!

Removing the stator is tricky at best and if the headwires are in good condition and it's working leave them alone for now. Get a can of compressed air and blow that motor housing out thoroughly. inspect with a flashlight and magnifying glass/loop for any damaged wiring on the stator coils, debris, etc. Inspect the rotor for build up of grease, dirt, rust, etc, clean it off. Remove old lubricant and re-lube. reassemble and try it again. Let us know how you do.

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 Posted: Sat Feb 20th, 2021 06:49 pm
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Steve Stephens
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I have a simpler explanation for the sparking.    I think your fan has a centrifugal starting switch located inside the motor.   Until the start switch cuts out when the motor reaches the proper speed, there will be some slight sparking.   Listen for some gentle scraping upon startup and, again, before the fan speed comes down.   It's normal.
The three arms of the start switch make contact with a brass cone shaped piece that goes up inside the switch assy. below.   As the fan comes up to speed the three arms move outward breaking contact with the center piece of the switch assy (not shown).    The switch assy should be fairly clean and free of oils and the springs in good condition and the switch arms able to move freely.






Last edited on Sat Feb 20th, 2021 06:53 pm by Steve Stephens

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 Posted: Sat Feb 20th, 2021 08:08 pm
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Noah Britt
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If your fan's style no. is 162628 with no suffix letter, your fan should be a centrifugal start model. If it has a suffix, then it might not have the centrifugal switch. Since you say the sparking goes away after the fan gets going, that narrows it down right away to the centrifugal switch, like Steve said. The centrifugal switch only engages on the startup and then again on the spindown, meaning that the brass-on-brass rubbing only takes place on the startup and spindown. Just like what happens with brushes and a commutator, you can expect sparking from the centrifugal switch as well. Sparking is the normal result when metal rubs metal. 


Even so, it would still be a good idea to open up your motor (this doesn't have to involve removing the stator) and clean everything: dust, grime, and like Elliot said, use compressed air to get dust and junk off the stator windings. Also, if you take the motor apart, clean the bearings and shaft and re-oil them with Zoom Spout oil or 3 in 1 MOTOR oil in the BLUE can. You may have already done this, but you should also clean the oil cups and replace the wicks, and refill the oil cups with the oil stated above.

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 Posted: Sat Feb 20th, 2021 08:47 pm
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George Durbin
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Steve Stephens wrote: I have a simpler explanation for the sparking.    I think your fan has a centrifugal starting switch located inside the motor.   Until the start switch cuts out when the motor reaches the proper speed, there will be some slight sparking.   Listen for some gentle scraping upon startup and, again, before the fan speed comes down.   It's normal.
The three arms of the start switch make contact with a brass cone shaped piece that goes up inside the switch assy. below.   As the fan comes up to speed the three arms move outward breaking contact with the center piece of the switch assy (not shown).    The switch assy should be fairly clean and free of oils and the springs in good condition and the switch arms able to move freely.







What Steve says!

99 out of a hundred Westy tanks can use a centrifugal switch tune up! Clean, clean, clean is the word of the day for these beauties! And while you are looking the switch over you can see what is needed for a tune up... Usually springs and spacers... I know Steve loves these tanks as do I!! Some maintenance gets rid of 95% of the sparks after you have clean and lubed the bearings!


Geo...:bow:bigfan

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 Posted: Sat Feb 20th, 2021 09:00 pm
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Steve Sherwood
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Take the cage and blades off, then remove the front cover, this will give you access to the rotor, it should pull straight out. Then you can see the start switch, if it has one.

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 Posted: Sat Feb 20th, 2021 10:41 pm
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Russ Huber
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The earlier centrifugal start stationary stamp steel models are actually the easiest to work on. The centrifugal mechanism is up front. You can drive the stator out by drilling 2 stator bolt holes in the housing out to 1/4" in diameter. This will allow you to use a drift punch as the the 1/4" hole in the housing will be wide enough for the drift punch to catch the stator lamination. You just go back and forth between the 2 drilled opposing holes driving the stator out evenly. You must free the centrifugal switch housing contact by removing 2 screws before you drive out the stator. Once the struts are back on the fan you will never know the housing holes were widened.

If you want to simply get your rotor out to clean the centrifugal mechanism and contracts just follow the pictures:D



































Last edited on Sat Feb 20th, 2021 10:42 pm by Russ Huber

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 Posted: Sat Feb 20th, 2021 10:50 pm
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Russ Huber
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Do not pound on the rotor shaft with a steel hammer. That is a no no.  :D

Just tap the front of the rotor shaft carefully to pop the rear bell with a plastic/rubber hammer. Do not distort the housing.

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 Posted: Sat Feb 20th, 2021 11:57 pm
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Bob Bosco
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Thanks, great pictures, I’ll probably just clean the switch, check the springs.

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 Posted: Sun Feb 21st, 2021 12:12 am
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Russ Huber
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Bob Bosco wrote: Thanks, I’ll probably just clean the switch, check the springs.
Thanks for your post. I have been meaning to get that junk stator out of that housing for the last 2 years. Fact Jack. :tumbs

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