New sprinkler/Undersized wire

[JLC]

I recently bought a 1 1/2 hp Flotec sprinkler pump for lake front sprinklers. I made a mistake. I have a small building down by the water that is powered by a fuse box, not circuit breakers. Anyways, I switched the pump to 115v and connected it to 12 awg wire that connects to a pump start relay with a run of maybe 50'. I set the timer and once it was time to turn on, all it did was hum and by the time I got it shut off, there was smoke coming from the motor?
By then, I ran out of time to do anymore with it until next weekend.
Shouldn't the motor have kicked off before it got that hot?
Do you think I ruined the motor?

 

[Valveman]

#12 wire should be large enough. Most likely when switching from 230V to 115V you picked up a ground or the wrong wire and instead now have 65V to the motor. The only protection a motor like that has is an overload, and it probably didn't draw enough to overload with half voltage. Might still work. Plug it into the correct voltage and give it a try.

 

[Sponsor]

 

[JLC]

#12 wire should be large enough. Most likely when switching from 230V to 115V you picked up a ground or the wrong wire and instead now have 65V to the motor. The only protection a motor like that has is an overload, and it probably didn't draw enough to overload with half voltage. Might still work. Plug it into the correct voltage and give it a try.

Thanks. I need to investigate further once I get there but at the moment Im running things through my mind as to what happened. I may have some #10. If so, Ill run that. I dont know enough about fuse boxes to make it 230v.

 

[WorthFlorida]

Just a review from the owners manual for the pump. Be sure you moved the dial to 115v setting. The power leads can be either way. The manual also includes a wire size chart. For your needs a 10 AWG is recommended, though with 12 gauge it should have worked without a load on the impeller. At 19.9 amps running under load, a 30 amp with 10 AWG wire is needed.

Was there an 115v old pump that you replaced? An old fuse panel can have 240 volts. I would remove the cover of the fuse panel and verify the wiring is good and do check that you have ~115v and at the motor. If the motor is toast and you cannot rewire for 240v, get the 1 HP motor. According to the manual, 1HP motor is also wired for 240v. At one time for irrigation pumps, 1HP pumps were 115v and 240v was not an option.

At the motor with the cover off and power disconnect or switched off, you should be able to get a finger on the centrifugal switch and shaft and be able to spin the shaft motor to be sure that the motor is not seized. Check the wiring for burns or melted insulation going to the start capacitor and centrifugal switch.

What the Valveman described maybe true since all motors have a locked rotor rating. With the correct voltage, and the motor seize (locked) it will draw current, the motor will get hot but it should not burn as in fire and not necessarily trip a breaker or fuse. This is a UL requirement. Pool and irrigation pumps use the same motors. One time my pool pump lockup and only noticed it when the pool water didn't look right, it could have been locked up for a week and the motor was hot enough to make toast but never tripped the 240v breaker.

 

[JLC]

Just a review from the owners manual for the pump. Be sure you moved the dial to 115v setting. The power leads can be either way. The manual also includes a wire size chart. For your needs a 10 AWG is recommended, though with 12 gauge it should have worked without a load on the impeller. At 19.9 amps running under load, a 30 amp with 10 AWG wire is needed.

Was there an 115v old pump that you replaced? An old fuse panel can have 240 volts. I would remove the cover of the fuse panel and verify the wiring is good and do check that you have ~115v and at the motor. If the motor is toast and you cannot rewire for 240v, get the 1 HP motor. According to the manual, 1HP motor is also wired for 240v. At one time for irrigation pumps, 1HP pumps were 115v and 240v was not an option.

At the motor with the cover off and power disconnect or switched off, you should be able to get a finger on the centrifugal switch and shaft and be able to spin the shaft motor to be sure that the motor is not seized. Check the wiring for burns or melted insulation going to the start capacitor and centrifugal switch.

What the Valveman described maybe true since all motors have a locked rotor rating. With the correct voltage, and the motor seize (locked) it will draw current, the motor will get hot but it should not burn as in fire and not necessarily trip a breaker or fuse. This is a UL requirement. Pool and irrigation pumps use the same motors. One time my pool pump lockup and only noticed it when the pool water didn't look right, it could have been locked up for a week and the motor was hot enough to make toast but never tripped the 240v breaker.




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Yep, I did for sure move the dial and my mistake was running #12 wire. What you say is exactly my plan-- open up the panel and see whats in there. I just ran out of time to check anything out after the fact so now Im worrying about whether I screwed this pump up. Thanks for all the tips, greatly appreciated

 

[Valveman]

#12 wire is not what caused that problem.

 

[JLC]

#12 wire is not what caused that problem.

What would be you 1st guess? Fuse box? Bad ground?

 

[Valveman]

Wrong wire, bad connection, or any of the above, but #12 wire would only reduce the voltage minimally.

 

[JLC]

Wrong wire, bad connection, or any of the above, but #12 wire would only reduce the voltage minimally.

Ok, thanks. Hopefully I will find it this weekend. As I said earlier, until I get there Im just running things through my head wondering why.

 

[JLC]

Wrong wire, bad connection, or any of the above, but #12 wire would only reduce the voltage minimally.

So I opened up my fuse box. Had a couple open circuits so I went ahead and switched it over to 240v. When I first turned it on, had no water, so I shut it off and checked to see if it was primed. It was but I noticed that the fitting I put in the priming plug with a pressure gauge may have been too long. I think maybe it was keeping the impeller from spinning. Anyways, its working good now and its switched to 240v. Thanks for your helpful tips.