Full Version: Any Electricians / Electrical Engineers in Here?
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Or maybe you stayed at a Holiday Inn Express? I'm trying to crowdsource some knowledge as I attempt to replace my hot tub pump and motor.

So I've got a Softub which if you're not familiar is a circular foam tub with the jets and everything and then a separate egg shaped thing that connects the water input/output/air for bubbles and a couple wires for the underwater lights. The egg has holds the pump and motor and the electrical control box. There's no heating element, instead the water is circulated through coils around the pump and sucks the heat from there. It's very easy to move and set up as it's lightweight and uses 110V hookup.

So, old pump leaked and blew. I entered the model number from the old one and found what I thought was a good replacement. As I was hooking it up however there was an extra hot wire coming from the control box to the pump and only a hookup for one on the pump motor. Turns out the old motor was a 2 speed motor and the new one is a single speed. The black wire for high speed and red for low. Called the guy I bought it from and he said others had just used the high speed as the low was just for circulation and not enough to actually heat. So he said wrap up the red wire with electric tape hook the high speed to the motor. He was wrong. I did what he said and everything seemed to be working. Jets came on and off, all the controls worked. Great. The jets will go off after an hour if you leave them on but according to the guy (who does not specialize in this type of tub) it will also heat with high speed. After an hour no jets were on to heat. They'd turn on if you pressed the button but the red "heat" light was on indicating that it should be heating. So clearly it heats on the low speed.

So, send it back and get yourself a 2 speed motor mturn. I can't find one that I can put those heating coils on. All the 2 speed spa pumps have some funky hump on them.

So I have two ideas. The first is to switch and hookup the low wire. The pump doesn't have a low speed but assuming the voltage from both wires is the same it should run on high whenever the control panel tells it to (i.e. the heat cycle). But I'd lose control of the jets. They would likely come on when using it anyway in cold weather because just the heat from the motor can't keep it at high temps with the lid off. But at least I'd have a "hot" tub.

Now, my question is what if I hook both wires up to the motor. The relay won't send power from both hot wires at the same time which would almost certainly cause a short. And there are two nodes to hook up to the same hot terminal. My coworker thinks that them just sharing that therminal might cause a short as the circuit tries to complete by running back up the other hot wire that's not pushing at the time.

I'm still trying to find a 2 speed motor that will work but if not want to make something work. Thanks in advance. I'll buy you a beer or give you free tax advice in return for you reply.
Interesting problem. You are really scraping the bottom of the barrel if you are posting it on this site. I am not an electrical engineer, just some experience with home and car wiring. My experiences with appliances has not been great. My first impression is to stay away from connecting high and low together. I think a short is a definite possibility in that scenario. And having a bare wire hanging around covered in only tape is a disaster waiting to happen, especially with something that holds water. I would at least put a wire nut and sealant on it, or better yet remove the unneeded switch entirely. But obviously the real problem is you don’t have the right pump. Do you know if this pump is designed for heating with those coils? Sounds like if you can’t find the right pump you might have better luck replacing the coils or the panel that will match the pump you now have. If you really like this tub and it’s worth the investment you would have a refurbished tub that will last much longer. I’m a safety first kinda guy so I don’t like to take too many chances where electricity and water combine. I’ve seen Hot Tub Time Machine so I know what can happen. If we don’t hear from you again we’ll assume you went back to 1985. And stay away from the Chernobli.
Yeah, I don't know if I'm trying to talk myself into doing something stupid or talk myself out of it but I think I need to try to find a two speed motor that will work. I bought the tub used and it had a good bit of mileage on it when I bought it. We've used it for 4 years and if I can put a few hundred dollars into it and get a few more years out of it then that would be great. I'd like to upgrade but now's not the time. Didn't even think about Hot Tub Time Machine, that brings a whole new element into it.
Found out the "hump" is a capacitor hump. Now need to find out what a capacitor hump is.
If you haven't tried it yet give eBay a shot. Almost every exotic part you could ever need is on there, used or new. Your best bet is to search by part # of you have it. I just sold an 8 year old washer timer on eBay for a washer that died on me a few years ago and I couldn't fix. I don't have the best track record with appliance repair. I'm not sure you should even listen to my advice. Not much luck with small engine repair either. Anything else I can fix the hell out of.
Yeah I was surprised that Ebay wasn't really turning anything up. I'm not the handiest but I enjoy trying and generally know when I'm in over my head. I've opened up the hot tub a few times since owning it to fix some small leaks so have some familiarity. It somehow got a very large leak and then the motor blew from pumping with insufficient water. I decided to replace the whole pump and motor assembly as it is relatively easy to swap out and wouldn't have to worry about where the initial leak was because it's all getting replaced. Good news is there's no leaks. Bad news is it won't heat. I found the manual, apparently it does heat on the high speed but starts out on the low and switches over after 5 seconds. For whatever reason it won't kick over to the high speed and I don't have a low so it's just dead. If I push the button the jets come on though.
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