Help With Reassembling Basic 110 VAC Motor

[Used_Cars]

My "Ridgid" brand shop vac stopped working in a puff of white smoke because I was vacuuming bees out of a junk TV set (while wearing a bee suit) and it started to "misty" rain. I thought I'd burned the thing permanent, so never tried to turn it back on.

Disassemble the motor housing and extracted the Motor, disassembled the motor. Very simple, very basic. Visual inspection shows the brushes both look good, no scorching or burning on the stator, it spins freely, the cord ohms good, the switch ohms good and the ONLY thing I can see that might have shut the thing off is a 1 1/2" "something" inside a protective sleeve on the interior windings of the motor. Assume this is a current overdraw protection, or thermistor, or something.

The windings ohm short where they should, and open where they should. I have very basic understanding of how motors work and that's where the question comes in.

I don't want to wire this thing wrong and risk burning it up. I can't remember which wire goes where. I have one constant wire from the AC cord that goes straight to the motor, and the other wire goes through the big, main Power Switch before it also goes straight to the motor.

I have four terminal clips to choose from, and I assume one wire goes on one side and the other wire goes on the other side, but I'm concerned that it matters which one goes where.

One side of this motor has a big letter "N" next to where the brushing clips to the windings, and the other side does not. I assume "N" is for neutral, but is Neutral the switched side, or the common side? (Please correct my terminology, it's been years since I really needed to put this knowledge to use.)

I can post pics if necessary. Hoping this text is descriptive enough to get help. Also hoping that it will work when I put it together, because disassembly and cleaning of the motor housing was a real PITA.

Other questions:

1) I decided not to lubricate anything inside the motor (grease, WD-40, etc...) because it would attract dust and eventually be a drag on the motor. Correct?

2) What's this fabric covered thing spliced into the windings inside the motor? i.e. What's most likely; current overdraw or temperature protection? Both?

I can post pics of all of this. It's right here on my desk next to my elbow. Thanks in advance.

[budm]

Re: Help With Reassembling Basic 110 VAC Motor

Yes, post pictures.
"the ONLY thing I can see that might have shut the thing off is a 1 1/2" "something" inside a protective sleeve on the interior windings of the motor" That this thermal protection incase the motor wiring gets too hot then it goes open circuit, so check to see if it shows resistance of <1 Ohm on that device.
N = NeutraL
L = Line
They usually use single pole-single throw power switch to break the Line when switch is off.
If they use Double-pole-single throw switch then they are breaking the L and N when switch is OFF

[Curious.George]

Re: Help With Reassembling Basic 110 VAC Motor

My "Ridgid" brand shop vac stopped working in a puff of white smoke because I was vacuuming bees out of a junk TV set (while wearing a bee suit) and it started to "misty" rain. I thought I'd burned the thing permanent, so never tried to turn it back on.

Have you since tried to turn it back on? I.e., the magic smoke getting out suggests something has given up the ghost (it's not a "resetable" failure). Trying to turn it back on would confirm that.

Is it a "one speed" vacuum? Is it reversible (blower)? Or, does it require you to move the "hose" to the exhaust port to reverse it?

Disassemble the motor housing and extracted the Motor, disassembled the motor. Very simple, very basic. Visual inspection shows the brushes both look good, no scorching or burning on the stator, it spins freely, the cord ohms good, the switch ohms good and the ONLY thing I can see that might have shut the thing off is a 1 1/2" "something" inside a protective sleeve on the interior windings of the motor. Assume this is a current overdraw protection, or thermistor, or something.

The windings ohm short where they should, and open where they should. I have very basic understanding of how motors work and that's where the question comes in.

[The STATor is the STATionary part of the motor. The ROTor is the part that ROTates.]

Have you verified isolation between each winding and the stator/rotor? I.e., that a winding hasn't shorted to the frame (even if the "other" continuity measures seem correct)

[Imagine touching the shaft while it is powered up only to discover the LINE has effectively been shorted to the rotor]

I don't want to wire this thing wrong and risk burning it up. I can't remember which wire goes where.

When taking a photo involved a trip to the drug store and a week's wait for the prints to arrived, it didn't make a lot of sense to photograph DAMN NEAR EVERYTHING. But, now, when you don't even have to PAY for the "processing" of the film and can view finished prints moments after taking them, its silly not to be taking photos every time you "do something".

I have one constant wire from the AC cord that goes straight to the motor, and the other wire goes through the big, main Power Switch before it also goes straight to the motor.

Polarized (3 wire) power cord? If so, the wire to the power switch is LINE (instead of NEUTRAL).

I have four terminal clips to choose from, and I assume one wire goes on one side and the other wire goes on the other side, but I'm concerned that it matters which one goes where.

One side of this motor has a big letter "N" next to where the brushing clips to the windings, and the other side does not. I assume "N" is for neutral, but is Neutral the switched side, or the common side? (Please correct my terminology, it's been years since I really needed to put this knowledge to use.)

NEUTRAL is electrically connected to GROUND -- GROUND being the "third wire" in the power cord. It often is not at GROUND potential owing to the IR losses in the NEUTRAL conductor (the GROUND conductor should never be carrying any current).

Other questions:

1) I decided not to lubricate anything inside the motor (grease, WD-40, etc...) because it would attract dust and eventually be a drag on the motor. Correct?

Correct. Any bearings/sleeves will probably be self-lubricating/sealed (e.g., sintered bronze).

2) What's this fabric covered thing spliced into the windings inside the motor? i.e. What's most likely; current overdraw or temperature protection? Both?

How many terminals enter/exit the "thing"?

I can post pics of all of this. It's right here on my desk next to my elbow. Thanks in advance.

Please do. And, review them before posting (nothing worse than looking at a bunch of "flash blooms" that washout all of the pertinent detail!

[Used_Cars]

Re: Help With Reassembling Basic 110 VAC Motor

Yes, post pictures.

[Used_Cars]

Re: Help With Reassembling Basic 110 VAC Motor

Yes, post pictures.
"the ONLY thing I can see that might have shut the thing off is a 1 1/2" "something" inside a protective sleeve on the interior windings of the motor" That this thermal protection incase the motor wiring gets too hot then it goes open circuit, so check to see if it shows resistance of <1 Ohm on that device.
N = NeutraL
L = Line
They usually use single pole-single throw power switch to break the Line when switch is off.
If they use Double-pole-single throw switch then they are breaking the L and N when switch is OFF

The AC cord is two-prong, no ground wire. The white wire goes directly to the motor, the black wire goes through a switch before going from there directly to the other side of the motor.

I double-checked the continuity tests. Calling the two sets of terminals posts "N1 and N2", and "Not N1 and Not N2":

N1 to N2 reads open
Not N2 to Not N2 reads open
N1 to Not N1 reads short
N2 to Not N2 reads short.

I can post a pic labeling the posts, terminals, whatever the word is, for clarity.

[Used_Cars]

Re: Help With Reassembling Basic 110 VAC Motor

Have you since tried to turn it back on?

No. Just assumed something fried and opened it up a couple months later.

Is it a "one speed" vacuum? Is it reversible (blower)? Or, does it require you to move the "hose" to the exhaust port to reverse it?

It's one speed. You "reverse" the hose to the fan's output to make it a blower.

[The STATor is the STATionary part of the motor. The ROTor is the part that ROTates.]

Thanks. Good to know I was at least in the ballpark.

Have you verified isolation between each winding and the stator/rotor? I.e., that a winding hasn't shorted to the frame (even if the "other" continuity measures seem correct)

After reading this, I just tested all four posts ("N1", etc...) against the Stator and all read open. Which I assume means it's good. Also I just posted continuity tests between all the terminals in the post above.

When taking a photo involved a trip to the drug store and a week's wait for the prints to arrived, it didn't make a lot of sense to photograph DAMN NEAR EVERYTHING. But, now, when you don't even have to PAY for the "processing" of the film and can view finished prints moments after taking them, its silly not to be taking photos every time you "do something".

Assumed that since it was so simple, simple text might be enough.

Polarized (3 wire) power cord? If so, the wire to the power switch is LINE (instead of NEUTRAL).

No, see above.

NEUTRAL is electrically connected to GROUND -- GROUND being the "third wire" in the power cord. It often is not at GROUND potential owing to the IR losses in the NEUTRAL conductor (the GROUND conductor should never be carrying any current).

No neutral to worry about here.

Correct. Any bearings/sleeves will probably be self-lubricating/sealed (e.g., sintered bronze).

Just noticed that the back side (away from the brushes) is a sealed bearing that also swivels.

How many terminals enter/exit the "thing"?

Four, see above

Please do. And, review them before posting (nothing worse than looking at a bunch of "flash blooms" that washout all of the pertinent detail!

Not my 1st rodeo.

Also, just noticed that the plastic housing that holds the bushings can be installed both (180 degree) ways against the Stator, which puts the white sleeved "thermal protection" thing (what's it called?) either on the "N" side or the "Not N" side.

[Used_Cars]

Re: Help With Reassembling Basic 110 VAC Motor

I decided to take pic and do a graphic of the continuity tests.

[eccerr0r]

Re: Help With Reassembling Basic 110 VAC Motor

Well that white sleeved thing probably has a thermal protection fuse inside to prevent a fire if motor overheats. If N1 is conductive to not_n1 then the fuse is probably okay. Determining if the windings themselves have a winding to winding short, you probably will need to look for a ring tester, or perhaps a low voltage transformer and feed to the Nx and Not_Nx poles and see how much average current flows (but you don't have a baseline, though comparing the two poles against each other probably is at least a start.)

It looks like the winding 1 and winding 2 are wound antiparallel, so to get opposite poles at the stator, power needs to be fed in opposite directions. Hopefully the connections to N1 N2 not_n1 not_n2 are connected properly externally? Where/how do they connect? As they need to be fed in opposite directions, I'd guess N1 and N2, or not_n1 and not_n2 (N1 XNOR N2? ) are connected together externally if there's not a separate driver for each winding?

Backing up, what exactly happened to the motor?

Did the motor stall while it was powered up? This would be the most damaging part, not the water entering. The water entering the bearings causing it to stall, however, is a destructive act. Water on the commutator causing contamination can cause damage. But water vaporizing off hot windings actually should help cool the motor making it last longer (until salts deposit on it or the water causes thermal stress causing cracks on the lacquer.)

[Used_Cars]

Re: Help With Reassembling Basic 110 VAC Motor

Well that white sleeved thing probably has a thermal protection fuse inside to prevent a fire if motor overheats. If N1 is conductive to not_n1 then the fuse is probably okay. Determining if the windings themselves have a winding to winding short, you probably will need to look for a ring tester, or perhaps a low voltage transformer and feed to the Nx and Not_Nx poles and see how much average current flows (but you don't have a baseline, though comparing the two poles against each other probably is at least a start.)

It looks like the winding 1 and winding 2 are wound antiparallel, so to get opposite poles at the stator, power needs to be fed in opposite directions. Hopefully the connections to N1 N2 not_n1 not_n2 are connected properly externally? Where/how do they connect? As they need to be fed in opposite directions, I'd guess N1 and N2, or not_n1 and not_n2 (N1 XNOR N2? ) are connected together externally if there's not a separate driver for each winding?

Backing up, what exactly happened to the motor?

Did the motor stall while it was powered up? This would be the most damaging part, not the water entering. The water entering the bearings causing it to stall, however, is a destructive act. Water on the commutator causing contamination can cause damage. But water vaporizing off hot windings actually should help cool the motor making it last longer (until salts deposit on it or the water causes thermal stress causing cracks on the lacquer.)

I don't know what happened to the motor. As mentioned in the OP, I was busily minding my own business in a bee suit ruthlessly murdering africanized bees and suddenly my weapon stopped working.

Look. I didn't understand a word of any of that. "Fed" this and "Fed" that. This is freaking electronics, not Chef Ramsay's Kitchen. It's hard enough trying to remember 30 year old electronics training (that I never used), without all these euphemistic words being thrown around. I have a white wire and a black wire. I have two brushes. All four of those things need to be plugged into those four terminals so I can put it together and see if it works. The only difference between one side and the other is one winding has the thermal cut off device and the other doesn't. If I install these wires backwards, or if I put the wrong color wire to the thermal protection side, will the motor burn up? Will it run backwards?

Will an AC motor like this one run backwards if you reverse the wiring?
Does it matter which wire (black vs. white) gets the thermal device thing?

Looking at my continuity tests, it's obvious to me that each brush plugs into each side, and each wire goes to each side. The wires aren't going side-by-side, and the brushes CAN'T go side by side. So the only questions are the orientation of the "N" side of the housing (thermal device side or the other), and what color goes on the "N" side.

[Sparkey55]

Re: Help With Reassembling Basic 110 VAC Motor

I don't know what happened to the motor. As mentioned in the OP, I was busily minding my own business in a bee suit ruthlessly murdering africanized bees and suddenly my weapon stopped working.

Look. I didn't understand a word of any of that. "Fed" this and "Fed" that. This is freaking electronics, not Chef Ramsay's Kitchen. It's hard enough trying to remember 30 year old electronics training (that I never used), without all these euphemistic words being thrown around. I have a white wire and a black wire. I have two brushes. All four of those things need to be plugged into those four terminals so I can put it together and see if it works. The only difference between one side and the other is one winding has the thermal cut off device and the other doesn't. If I install these wires backwards, or if I put the wrong color wire to the thermal protection side, will the motor burn up? Will it run backwards?

Will an AC motor like this one run backwards if you reverse the wiring?
Does it matter which wire (black vs. white) gets the thermal device thing?

Looking at my continuity tests, it's obvious to me that each brush plugs into each side, and each wire goes to each side. The wires aren't going side-by-side, and the brushes CAN'T go side by side. So the only questions are the orientation of the "N" side of the housing (thermal device side or the other), and what color goes on the "N" side.

The whole thing is a series circuit. The rotor windings are in series with the commutator brushes and the brushes on each side are in series with the field coils. The BLACK wire coming from the power cord goes to one terminal of the switch. The other switch terminal goes to one end of a field coil. The WHITE wire of the power cord goes to one end of the OTHER field coil. Remember that BLACK wire is HOT and WHITE wire is NEUTRAL. Never put the switch in the NEUTRAL wiring.

[Sparkey55]

Re: Help With Reassembling Basic 110 VAC Motor

You can check the thermal fuse by a continuity check across the field coil winding that it is installed in. Beep is good and no beep is bad (open thermal fuse). Most likely rated for 121 degrees C.

[redwire]

Re: Help With Reassembling Basic 110 VAC Motor

For the thermal cut-off, these are a pain to work with because you would have high-current crimp connections to it. Soldering a TCO is very risky, due the heat tripping the fuse. I crush open the eyelets with pliers.

Rigid Shop Vac thermal fuse replacement youtube vid microtemp TF121C

Don't worry about wiring it wrong and burning it out, you can put a light bulb in series to limit power, or even run it on a low voltage AC or DC power supply. It's a universal motor, AC or DC. They may even run slow on 24V.

I'd apply 20 or 30 weight motor oil to the bearings, one drop. It doesn't cause extra drag, as the load is the vacuum.

Don't run the motor with no load (impeller) and full mains voltage. It would over-rev and damage the motor.

[will62]

Re: Help With Reassembling Basic 110 VAC Motor

For the wiring, go to about 4:45 in on this video:

https://www.youtube.com/watch?v=Ekx0-TJzOaw&t=456s

[budm]

Re: Help With Reassembling Basic 110 VAC Motor

Wiring.
Once you have it all together, if there is no open circuit then you should see low resistance reading between the two blades of the AC plug when power switch is closed.

[eccerr0r]

Re: Help With Reassembling Basic 110 VAC Motor

Weird, the windings look deceptive in the pictures, thought that one was left hand wound and the other right hand wound. The connection diagram would imply both need to be wound the same way -- hence the curiosity on how it was wired before removal and a mere guess at how it was supposed to be connected.

As long as you don't shunt power and have everything in series, you should be OK though hooking it up wrong would not allow the motor to spin. If you were to just hook up power across one field and hook the brushes to the second stator (incorrect), then you could fry something...

[Used_Cars]

Re: Help With Reassembling Basic 110 VAC Motor

Wiring.
Once you have it all together, if there is no open circuit then you should see low resistance reading between the two blades of the AC plug when power switch is closed.

Okay.

So the more I am forced to type out what I think I know, the more I actually KNOW what's going on. I've looked at this and thought about it enough to (think I) know that the only real question I have is which side of the circuit the thermal cut-off needs to be on (thanks, redwire).

Does it go on the white, common, "always felt" side, or the black, switched side? Does it matter?

Since I never tried to run the motor after it cut-off, I have no reason to believe that the components in the motor aren't 100% functional. The fact that the thermal cut-off side of the windings read short should be enough to show it's still good. It's never cut-off before. Seems unlikely to me that the one time it pops is also the time that kills it, but damages it in such a way that, when cool, it reads a short.

I intend to just put it back together and see what happens, but the one thing that holds me back is which wire goes to which side of the motor. As soon as I know that, I can start reassembling it and see if it still works.

FYI, I'd like to endorse this "Ridgid" brand vacuum. It has loyally served me for years of hard, professional use, vacuuming up the worst-of-the-worst, such as drywall dust and thin-set powder (used for tile installation, and is as small as drywall dust and much more abrasive). And also water, as I use it to take up spills, pump smaller amounts of water, etc... It also makes a decent blower for yard work, if you can get used to being tethered by a cord. And it's not nearly as loud as some brands I've used, "Genie" being the worst.

[Used_Cars]

Re: Help With Reassembling Basic 110 VAC Motor

Wiring.

Oh. I posted the previous post before looking at your modified pic. I'll follow that diagram and post results. Thanks for the artwork.

[eccerr0r]

Re: Help With Reassembling Basic 110 VAC Motor

Yes ideally the thermal cutoff is at the hot end of the chain - black/small blade/... side along with the main power switch and any other fuses. However thermal cutoffs were usually designed to be one-time and need to be replaced when tripped.

Shop vacs are neat. I only have a small 1.5HP "shop vac" branded one that I used to ...

... vacuum out a yellow jacket nest...

It started raining once when I had it set up to vacuum out the nest and it survived. Dodged a bullet there? Not sure.

[Sparkey55]

Re: Help With Reassembling Basic 110 VAC Motor

Okay.

So the more I am forced to type out what I think I know, the more I actually KNOW what's going on. I've looked at this and thought about it enough to (think I) know that the only real question I have is which side of the circuit the thermal cut-off needs to be on (thanks, redwire).

Does it go on the white, common, "always felt" side, or the black, switched side? Does it matter?

Since I never tried to run the motor after it cut-off, I have no reason to believe that the components in the motor aren't 100% functional. The fact that the thermal cut-off side of the windings read short should be enough to show it's still good. It's never cut-off before. Seems unlikely to me that the one time it pops is also the time that kills it, but damages it in such a way that, when cool, it reads a short.

I intend to just put it back together and see what happens, but the one thing that holds me back is which wire goes to which side of the motor. As soon as I know that, I can start reassembling it and see if it still works.

FYI, I'd like to endorse this "Ridgid" brand vacuum. It has loyally served me for years of hard, professional use, vacuuming up the worst-of-the-worst, such as drywall dust and thin-set powder (used for tile installation, and is as small as drywall dust and much more abrasive). And also water, as I use it to take up spills, pump smaller amounts of water, etc... It also makes a decent blower for yard work, if you can get used to being tethered by a cord. And it's not nearly as loud as some brands I've used, "Genie" being the worst.

Like was stated earlier, a non-resetable thermal fuse, one that is designed to burn open circuit can not be reused. IF what you said in your original post is true about it shutting off then the thermal fuse is history. But IF you had the shop-vac connected to a circuit breaker type of power strip it is possible that the resetable circuit breaker on the power strip stopped the vac instead of blowing the fuse.

[budm]

Re: Help With Reassembling Basic 110 VAC Motor

BYW, based on this measurement you provided: https://www.badcaps.net/forum/attach...2&d=1521157574
N1 to Not_ N1 did not show open circuit so that means the Thermal protection did not go open circuit.
Once you put it all together to check to see if it shows open circuit or not between the AC plug's blades then we can go from there. Be careful on those brushes when putting them back together.