Pump Trips Breaker in 3 seconds

May 25, 2012
7
0
#1
I'll try to give as much info as possible...

Summary:
replacing 1HP pump with 1.5HP, did impeller and seal kit as well. 25K IG pool with 1.5" piping, Hayward 2600 series pump housing and S240 filter. Motor set and wired proper for 115V. New motor trips 20A breaker, another new motor sitting on ground never installed or wet also trips breaker after 3 seconds running.

Details:

25K gallon in-ground

Hayward S240 Sand Filter
1.5" Piping
Hayward 2600 series pump/filter housing
All original wiring done professionally. Inside 30A feeds box 10 feet away outside which has dedicated 20A dual pole for pump. Wiring from breaker to pump is maybe 6 feet long and 12AWG.
No timer (bought one to install when all this is sorted)
Old pump - 1HP Magnatek, 7.2/14.4A, 115V - bearings went bad and needed new pump. (very old - screws were all rusted and pump could not be disassembled) We have had the house 6 years with trouble free pool/pump operation, pool is about 14yrs old

I did some research measuring feet of head and all that and seemed 1.5HP would be a better fit, hoping this isn't the root of my problem.

Installed the new AO Smith UST1152 (1.5HP, 115V, 9.3/18.6A) after switching it to 115V. I turned it on and immediately the breaker tripped. I looked at the wiring and found the ground wire insulation was a little rough and it shorted on the screw at the black wire. Woops...

Decided to put new connectors on the hot and neutral and trimmed back the ground to good insulation. The connectors for the hot and neutral are female spade type and the wire at the motor is stranded type.

With everything tight (including external case ground) I reset the breakers and it fired up for about 3 seconds and tripped the outside 20A. I reset the breaker and tried again, and again ran for 3 seconds and tripped the breaker.

I learned somewhere along the way that a wrong size impeller could cause this so I replaced the impeller (with seal kit) with a Hayward SP2615X. It was definitely a little bigger and though I had it solved. Nope - turn on breaker, runs for 3 seconds and shuts off. When I look at the pool I can see the water is moving, pressure at the filter is around 15-18. The old pump also pumped fine it was just LOUD, so no obstructions.

The new pump seemed like it had a lot of vibration and was noisier than the old pump pre-bearing failure. I talked with the pump vendor and got a new one. Took the new one straight back to the pump area, and without it ever touching water or being installed (still had the rubber cone on impeller threads even) I wired it up (same as old pump, same as other new pump, switching it to 115V) and ran what should have been a bench test. Flip the breaker on, it ram for 3 seconds, maybe got 4 out of it, and it tripped. I. Am. Stumped.

The only thing I haven't done is replace the breaker. I bought one last night but in my hurry, got the wrong physical size. :|

I looked inside the outside CB box and checked all the connections and everything seemed fine. One thing I did notice - the wire to the pump starts in the box as solid wire, but where it comes out of the conduit, it's stranded. The stranded is good here as it's tight quarters and the stranded is more flexible. I tested resistance from pump to breaker and all was good. (although a multimeter tests that with little load) Also, tried measuring draw with my multimeter that is fused for 20A max and it blew that after a half second or so. I'm guessing it's not as robust as a household CB so not sure how much credibility it has. I'd like to get a clamp type ammeter but they're 60-70 bucks and up...

Going to try a new breaker but -

Is there anything I am missing?
Was my "bench test" OK or will the motor trip the breaker without a proper load on it?
 
May 25, 2012
7
0
#3
Ohm_Boy said:
wired proper for 115V
[quote:1s8sbz39]dedicated 20A dual pole for pump
Dual pole means 220v, not 115v. :!:[/quote:1s8sbz39]

I'm sorry - there are only 3 wires black, white and ground. I think what I'm referring to is maybe a ground fault CB? The black and neutral are both connected to the breaker on separate screws. So, dual pole is probably not the right term for this? :oops:
 

JasonLion

LifeTime Supporter
Platinum Supporter
TFP Expert
May 7, 2007
37,879
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Silver Spring, MD
#4
Welcome to TFP!

240 volt breakers are twice as wide as 120 volt breakers and usually have two switch levers connected by a bar. Wire color is suggestive of what voltage is involved, but that doesn't mean that is what the voltage actually is. GFCI breakers have connections for both hot and neutral, but a 240 volt breaker would also have two terminals, so that doesn't eliminate the possibility. Do you have a multi-meter? It should be easy to check the voltage with a meter.

Everything you describe sounds correct, and I would expect it to work. The most likely possibility is a wrong voltage or bad circuit breaker, especially since it is a GFCI breaker. However there are any number of less likely possibilities, including incorrect setup of motor voltage, partial shorts in the wiring, water in the electrical conduit, other loads on the same breaker, and so on.

Increasing your pump size wasn't a great idea. The larger pump will increase your electrical costs, reduce filter effectiveness, and not provide any significant advantages to counter those disadvantages. However, that has nothing to do with the breaker tripping. The motor is rated below 20 amps, so it should work.
 

bk406

Well-known member
Dec 3, 2009
2,690
0
Central Massachusetts
#5
Steve85 said:
Motor set and wired proper for 115V. New motor trips 20A breaker, another new motor sitting on ground never installed or wet also trips breaker after 3 seconds running.
Steve85 said:
The black and neutral are both connected to the breaker on separate screws.

The way its wired at the breaker is for 240 volts. If its configured at the pump for 115 volts, thats the issue. For 115VAC, you need the black wire on a single pole breaker, the white wire on the neutral bus, and the ground wire on the ground bus.
 
May 25, 2012
7
0
#7
I will double check what's in the box and measure for voltage on what I thought was the neutral.

I thought for 240 I would have 4 wires to the pump - two hot, neutral and ground.

I wish I was at home to check stuff now!
 

bk406

Well-known member
Dec 3, 2009
2,690
0
Central Massachusetts
#8
240 motors like that dont need a neutral. The reason the drier and the oven generally have a neutral is because of timers, etc run off one of the 120VAC legs, so a neutral is needed to return that current back to the main panel.
 

Soupy

LifeTime Supporter
Jun 23, 2011
62
0
#9
Steve85 said:
I will double check what's in the box and measure for voltage on what I thought was the neutral.

I thought for 240 I would have 4 wires to the pump - two hot, neutral and ground.

I wish I was at home to check stuff now!
Nope! For 240v you essentially have 2 hot and a ground, no neutrals.
 

Bama Rambler

Mod Squad
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TFP Expert
Jun 23, 2009
22,789
3
105
SouthWest Alabama
#10
240 volts to the pump will be three wires. L1, L2 & Ground.

You almost never see them with 4 wires because they don't need 120 volts.
Home appliances (dryers, ovens, etc.) will have 4 wires because they use 120 volts for the controls, so they need the neutral.

[edit] I've been beat again, :hammer: but as you see we all had the same idea! [/edit]
 

bk406

Well-known member
Dec 3, 2009
2,690
0
Central Massachusetts
#11
Bama Rambler said:
240 volts to the pump will be three wires. L1, L2 & Ground.

You almost never see them with 4 wires because they don't need 120 volts.
Home appliances (dryers, ovens, etc.) will have 4 wires because they use 120 volts for the controls, so they need the neutral.

[edit] I've been beat again, :hammer: but as you see we all had the same idea! [/edit]
:mrgreen: :mrgreen:
 
May 25, 2012
7
0
#12
There is great promise!

Question then for tonight - the "wiring diagram" they provide is rudimentary at best (I do a lot of car stuff with very detailed diagrams) does it matter which hot wire goes on which terminal, L1 and L2?

And yeah, the dryer thing did throw me off, I had to relocate ours a few years ago and did it with the help of an experienced friend - 4 wires. I will check the white wire to the pump for voltage.

Thank you all so much. I promise to return with results this evening (or tomorrow if we get lightning again).
 

JasonLion

LifeTime Supporter
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May 7, 2007
37,879
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Silver Spring, MD
#14
bk406 said:
For 115VAC, you need the black wire on a single pole breaker, the white wire on the neutral bus, and the ground wire on the ground bus.
This is not true of GFCI breakers. 120 volt GFCI breakers have a separate terminal for neutral on the breaker, and a coiled white wire coming out of the breaker that gets connected to the neutral bus.

See for example this page which has some good drawings of regular 120 and 240 volt breakers, and then at the bottom shows how a 120 volt GFCI breaker is wired.
 
May 25, 2012
7
0
#15
Defining "know just enough to be dangerous" one job at a time...

Switched the voltage selector to 230, turned the breakers back on and it fired up and is running smooth and quiet.

It's amazing how terrible it sounded with on the 115V setting. I was convinced there was something wrong in the motor.

Thank you all for your time and help. Lessons learned - I didn't recognize the breaker and wiring as a 240 setup and when verifying voltage didn't test ALL wires present at the motor.

Now to install the timer - err call someone to anyway.

Also going to monitor the consequences of the "upgrade" to 1.5HP. I need to invest in some sort of solar heating method (or cut neighbor's trees down) to supplement the propane so maybe the upsized pump will come in handy...
 

bk406

Well-known member
Dec 3, 2009
2,690
0
Central Massachusetts
#16
JasonLion said:
bk406 said:
For 115VAC, you need the black wire on a single pole breaker, the white wire on the neutral bus, and the ground wire on the ground bus.
This is not true of GFCI breakers. 120 volt GFCI breakers have a separate terminal for neutral on the breaker, and a coiled white wire coming out of the breaker that gets connected to the neutral bus.

See for example this page which has some good drawings of regular 120 and 240 volt breakers, and then at the bottom shows how a 120 volt GFCI breaker is wired.
I know how to wire one. I've done many. I didn't see where the op said he had one, though. The way I read his post was he had a dipole in the box, not a gfci. I didnt want to confuse him be describing something he didnt ask about :wink:

Steve85 said:
Switched the voltage selector to 230, turned the breakers back on and it fired up and is running smooth and quiet.

...
Glad we could help. :goodjob:
 

scooperhsd

Well-known member
May 11, 2009
395
0
58
Youngsville NC
#17
The next thing you should think about - since this is for a pool pump - you probably want a 240V GFCI breaker on the pump circuit. The one I have is a 20 AMP dual pole 240V GFCI CB (GE brand) - takes two slots on the panel, and has a neutral wire coil that is connected to the neutral bar. It also has 3 terminal screws - L1, L2, and Neutral - and I ran all of those to my timer (as well as a ground). The neat thing about doing it this way is that if I wanted to run a 120V pool pump (instead of 240V like I am now) - I would just need to take one of the L wires off the load terminal in the timer, and jumper it to the neutral terminal in the timer - so I could run a 120V pump off a 240V timer. And yes - I have tried this out and it worked like a charm.