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frozen motors


vikingGoalie

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So I got a hot tub from someone who was getting rid of it. It worked at the time and was properly winterized by the folks they used to service it.   I moved it to it's new location, and then it sat for a little over 2 years :(   Life events prevented me from getting the wiring done until recently.  I have it wired up I have put a voltmeter on the terminal block and have the correct voltage.  I have 2 motors both humm but don't kick over and start rotating.  The blower works.  I did bleed the lines just in case there was an airlock in play.  My question is I think I just need to rotate the motors to get them freed up so they will spin once the capacitor hits them to go.   So the one motor I have to move the blower just get access to the back of it where cover is.  THe other is a 3hp Century and I got the cap offoff and under that I have this:  https://picclick.com/AO-Smith-Motor-Century-30-Horsepower-230v-2-Speed-184312138494.html#&gid=1&pid=5

I'm just asking before I tear down further I think I need to just undo that slotted bolt on the right side between the copper V that is formed (and recessed) and that V comes off ?  I'm asking because they way this is mounted I can't really get at easily and I really don't want to disconnect the entire motor from the tub to do this if I don't have to.    I only saw this image because I used my phone to reach back in there and take a pic.  I just linked this stock image up because it's identical to what I see and the same motor.   Any thoughts?   Thx.

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See if you can spin the part with the springs on it...carefully..or undo the connection at the face of the pump end where the plumbing attaches and get your finger in there to give it a spin. Had one last week with a similar issue and was able to get one half of my oil filter wrench/pliers in between the impeller grooves and get it to free up. Some pumps will have a bit of space between the wet end and the motor where you can get vise grips on the motor shaft and spin it a bit at a time. 

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thx guys!  I did get a big pair of pliers on the motor shaft between the wet part and the motor and turned it ever so slightly and did that for about 5 minutes, still humms no spin but I'm not sure how much I'm actually turning it as it feels like I am but.,,   The other motor I got the plastic cap off there is no nut for a wrench :( but there is a slot for a screwdriver to turn the motor. I torqued on it pretty hard and didn't budge that motor.   This is becoming a quest now.... I might end up taking both motors out just so I can really get at them.   Not really liking replacing each one at over $300 each.  But we'll see.    Just how frozen do these motors get if they sit for a while, cause they seem to be pretty frozen.

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Yes they will have to come out. Rebuilding them is a bit cheaper than replacement.

22 minutes ago, vikingGoalie said:

Just how frozen do these motors get if they sit for a while, cause they seem to be pretty frozen.

See it all the time. Free hot tubs are rarely free.

Worst thing that can be done to a hot tub is to leave it without water for an extended period of time. I won't winterize spas anymore unless the rare case where someone is going away for the winter and can't be there to check on it. When you take the water out air gets at everything. Seals around jets will shrink, Heater elements will rust and there is just to much liability for me. Cover blows open half way through winter and fills with snow then thaws and freezes again then come Spring and they start it up and it has cracked plumbing. Plus you pay $200 plus to get it winterized at $40 a mth to keep it running you are not saving much. JMO

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just an update as this is on going.   So got both motors disconnected and out of the hot tub.   First pump the motor I think is fine it spins freely, but the impeller part in the plastic pump portion is stuck.  I suspect this is true for both of them.  Didn't have time tonight to get the impeller off, but i figured this out because took the through bolts out and then I could easily and freely rotate the plastic impeller which is seized on the shaft of the motor.   Anyhoo next up is tapping this thing apart and then putting the stator in my vice grip and using an oil wrench hope to spin the impeller off the shaft.   I haven't done my research yet but can you buy/replace the guts of the impeller that's seized?   

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I'm in central PA.

I saw your post after i already got things apart.  I had to use a rather large oil filter wrench to get the one impeller off it was *really* on there.  Both impeller are the same even though they are different motors.  Looks like the shaft part got swelled up because of rust on the shaft of the motor and broke, jamming the whole thing up.  2 pics of each motor first first 2 are motor 1, second 2 are motor 2...

image.thumb.png.3ae11b72e2153b69cd216797e4b7dceb.png20200920_170206.thumb.jpg.21d7805754435f4002da12174ac9080e.jpg20200920_165652.thumb.jpg.38219a8edf944e75841af016bffa73af.jpg20200920_165658.thumb.jpg.01fc5f6d6f74d71d7d8e0f10b6b8ded3.jpg

 

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so the impeller, i got them off using a very large oil filter wrench with the stator held in a bench vice wrapped in carpet to protect it. the first one above was *really* stuck and took a lot of persuading to get to turn.

The impellers are the same for both. pics of impeller. The shaft had swelled because of rust on the motor shaft I bet so it cracked and jammed it all up. Pic of wet end with part # as well.20200920_170001.thumb.jpg.78c9a2c52ad734b24ac8d188e9074bcd.jpg20200920_170011.thumb.jpg.d4bacc51767f65b8a1cb22aaae5675e6.jpg20200920_165938.thumb.jpg.1815dc8dd31c971fdd17855fd43d3488.jpg20200920_165808.thumb.jpg.a058c884923ce0e9b6acd0b85c9d5978.jpg

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so my plan right now is to deal with the rust on the motor shafts,  I have 3-1 oil on the shafts right now and tomorrow gonna work on getting the rust off the shafts of the motors first with a brass brush but i have some sand paper i use for knives that should work well as well.

Get the right parts and put it all back together.  Thankfully I believe the bearings of the motors are fine,  they spin very easily.  The one stator does have a bit of rust on the stator part but not sure if I should deal with that or just leave well enough alone there.   Anyhoo, i'm pretty hard core diy on just about everything around the  house but this is my first tearing a spa motor apart ;)   thx for help!   (oh don't mind the messy work bench, i had tried the strap wrench first and that just wouldn't turn it,  I used these:  https://www.walmart.com/ip/Hyper-Tough-Oil-Filter-Wrench-63-5mm-116mm-Model-1208/55524395  to turn the impeller off and they work super well for that.

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only thing with running the motor is i don't have a 220 line out in my workshop. I'm  still looking at prices but seems like this: https://www.poolzoom.com/3-hp-impeller.html?gclid=CjwKCAjw-5v7BRAmEiwAJ3DpuLnfNJ9rzD5X3oZaTOiShNUTTlHfAm3A8OBmkYSod5NVHKdkqyTcYRoCAxYQAvD_BwE 

 

is a pretty reasonable deal, can get the impeller and other bits i need for roughly $38 per motor.  do i need more then the seal assembly, impeller piece and some silicon sealent? (I through the slinger piece in there as well as they are pretty cheap, but i do have those from the old impellers).     i'll go watch a youtube or two on this part.   ;)     anyhoo thx again everyone.

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I like to replace the pump housing o-ring and bleeder o-rings while I have it apart if I can. Saves another project later. It wouldn't hurt to slap in a new front bearing, they are pretty cheap, but I am not sure which you need. Maybe @CanadianSpaTechknows?

Just to be clear, you need silicone o-ring lubricant not silicone caulk/sealant.

 

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7 hours ago, vikingGoalie said:

only thing with running the motor is i don't have a 220 line out in my workshop

You can run 110V just move the hot lead for low or/then high. I just use a grinder to knock the rust off and to lower the high points then spray it with rust paint when done. I will use the brass thread from the old impeller to protect the threads while cleaning it up.

 

2 hours ago, RDspaguy said:

Just to be clear, you need silicone o-ring lubricant not silicone caulk/sealant.

I use just a little silicone sealant on the bottom half of the seal that goes into the wet end housing it's self as an extra layer of protection.

Bearing should be ok if spins freely and the impeller shaft splitting was the root cause but if there is a lot of rust in that area then it should be a 6203 bearing...I use the old bearing on top of the new one and a 2" or 3" long 1" round hard plastic Sched 40 tube/fitting or even a long/deep socket when hammering it back on in to place. 

7 hours ago, vikingGoalie said:

(I through the slinger piece in there as well as they are pretty cheap, but i do have those from the old impellers)

Slinger piece...not sure what you are describing here

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17 hours ago, CanadianSpaTech said:

Slinger piece...not sure what you are describing here

this:  https://www.poolzoom.com/slinger.html

  the impeller piece says 2HP in the center so figure I just get the same, even though the one motor is 3HP.       Once again thx for the help on this.  I think I'm gonna live dangerously ;)  and not mess with the bearings right now.  Honestly it wasn't that hard to take these motors out and apart so if I have to deal with that down the road I will.  The only real difficult part was the one impeller took significant force to spin off.   (thank you oil filter wrench)

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so i know this is kinda the thread that keeps going ;)  but i am on a mission to do this myself.  

so i took the advice and wired up a cord so i could run the motor on 110v.     so I think the start capacitor's on both motors are probably shot.  The motor doesn't rotate super easily but not hard at all by hand.   but this is what goes on.  off to find my multimeter and see if i can discern if the capacitor's are bad....

 

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On 9/21/2020 at 8:39 PM, vikingGoalie said:

Honestly it wasn't that hard to take these motors out and apart

Shhhh

During the test in the video is it 110 wired to the low speed or high speed? or have you tried both?

Looks like the shaft cleaned up nicely. 

Can you wire it back up in front of the spa for 240VAC and test it there to see if it just needs better power supply to start on it's own?

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24 minutes ago, CanadianSpaTech said:

Shhhh

During the test in the video is it 110 wired to the low speed or high speed? or have you tried both?

Looks like the shaft cleaned up nicely. 

Can you wire it back up in front of the spa for 240VAC and test it there to see if it just needs better power supply to start on it's own?

lol.  i mean it was really hard to take this motor out,  hire a professional !

so i wired it to low, don't wire it to the high it won't quite run right and try to draw to much amps. (i tried it for a brief sec)   i think high needs both phases where as low just draws on one leg i.e. 110.  i might be completely wrong as i didn't google that lol.  but it makes sense in my head anyway.

I thought that myself, the 240vac might be what it needs, i guess it doesn't hurt anything to try that but i'll have to wait until tomorrow when it's light out.  I watched a youtube though where a guy did this and the motor started right up so I'm thinking it's most likely the capacitor, but. but.   it is both motors doing this.   The first motor actually started up the first time without help,  but refused to do so any attempt there after.  so the voltage thing might be it.  dunno.  stay tuned on that i'll try it.

It would be nice if I could just test theses but while my harbor freight multimeter has a capacitor setting but it is a retarded you gotta plug the capacitor in and it won't go up very high anyway.  so a 2 prong capacitor you can plug in but normal bigger capacitors like on a motor it's no good for.    

 

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vikingGoalie, Thanks for documenting this.  I'm going through a motor rehab project as well and it's good to have a reference of your experience.  I have nowhere near the experience of the guys helping you, but I can tell you about my experience.

I bench tested all the pumps in my 'free' inherited tub using 120v, while I was waiting for my electric to be hooked up.  I had a circulating pump that only draws .63 amps and I got the same behavior as you showed in your video.  It needed help for it to spin, and sometimes I couldn't get it to stay spinning.  I was convinced it was dead.  When the 240v service was installed, it started and runs like a champ.

I had other 10 amp pumps that ran great, albeit slow, on 120v but now trip my GFCI.  I think that's a whole different issue (ground fault I think) but my point is that what I saw on 120v didn't really predict what I saw on 240v. I suspect that if I had run these pumps on a GFCI protected 120v circuit it would have tripped as well (that's my next step when I get one of these pumps removed).

CanadianSpaTech, you mentioned testing the pump near the tub using 240v.  Is it OK to hook up a pump to the spa pac and test it without water at 240v?  Should this only be done with the volute off? That would be a really helpful test for me as I rehab these tripping pumps.

Thanks,

Rob

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7 hours ago, rmcderm313 said:

Is it OK to hook up a pump to the spa pac and test it without water at 240v

Sure... just long enough to test it. I normally wouldn't but I would advise you to disconnect the heater. If you do it with the wet end off you need to use nuts on the threaded rods to keep the front and back of the motor in place as you can see in the last photo Viking posted...or reattach the wet end

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grr.  impeller parts didn't come yet,  should be here tomorrow.   oh just btw. I talked to a guy who runs a hot tub store and does service.  he told me that it's normal that 240v motors to not start up like that when wired to 120v.  Which if you think about it makes sense, the start capacitor says right on it that it's 250v, so quite possible it won't charge up enough to kick the motor over when wired to 120v.     i spent some time today constructing steps to the hot tub.    i'll post back once i have the motors in.

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so just got the parts, putting the stuff back together and i realized that the slinger piece is a bit of an oddity.

if you look at the diagram it's number 11.  so it looks to me like it is between the volute and the motor.  but I know for a fact it wasn't when I took it apart.  it was on the inside of the volute sitting down in the hole below the seal.   thing is i went and watched this guy (good video for anyone reparing a motor/wetend) 

he is actually taking apart a waterway wet end, and I see the slinger piece fall out when he takes it off but he does not put another one in, and he is the "spa guy". so now i'm debating if i put this slinger piece in at all, and if i do where exactly as in his video the piece that falls out is between the motor and volute, i know in my case both pumps had one and they were not between the motor and the volute.  thoughts?

image.png.902b8bff3130674dc0bbda0c28b76752.png

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Not really a needed part. Think the design is to keep water from running back along the shaft to the bearing if the seal fails. Most pumps just have a rubber "washer" the sits at the face of the motor...I usually get the rebuild complete and then see the washer sitting on the bench...lol. Spa Guy vids are good.

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16 hours ago, vikingGoalie said:

he is the "spa guy

He is A spa guy, not THE spa guy! But not a bad video for first timers, I guess. I didn't watch the whole thing, but skipped through it. Didn't see anything I seriously disagree with.

The slinger thing, as Canadaguy mentioned, often gets left out. It's purpose is to protect the motor bearing from water tracking down the spinning shaft. It is moderately effective, and can add years of life to your bearings. Older pumps did not have them, and so us older guys often forget to put them back on. 🤪 I have several floating around in my tool bag even now.

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