water pump


Old 08-03-05, 06:33 AM
Thread Starter
Join Date: Aug 2005
Posts: 19
water pump

i'm going to be installing either a 1 hp or 1 1/2 hp water pump to pump water out of a lake to water the yard, it wont be on a sprinkler. it's a 150 foot run, what size wire & size breaker should i install to keep to keep from having voltage drop, the pumps i have looked at(suregard) are 230 volts. should i run the wire to a breaker dox then to a gfi? is there a special gfi for 230v,s. thanks reid 37.
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Old 08-03-05, 09:14 AM
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Join Date: Feb 2005
Location: Near Lansing, Michigan
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You need to pick out the pump first. You will need the nameplate ratings from the pump motor to properly size the conductors and breakers. If you have a pump in mind, post back with the running amps, locked rotor amps and minimum circuit ampacity. From that we can help you pick the conductor size and breaker size. Horsepower ratings do not accurately correspond to electrical requirements as they vary by manufacturer and motor type.

This pump will not need GFCI protection, unless the manufacturer requires it. It will however require a weatherproof disconnect near the motor.
Old 08-03-05, 06:24 PM
Join Date: Aug 2004
Location: NA
Posts: 1,065
Branch circuit ampacity for conductors is determined by table 430.148 FLC for the given voltage and horsepower. That FLC rating is then multiplied by 125%.

1.5 hp 230 volt [t 430.148].....FLC 10 amps 10A x 1.25 = 12.5 amps
table 310.16 for 60 C ampacity......14 Awg copper minimum

Overcurrent protection using inv.time circuit breaker is determined by table 430.152 and mutiplying by 2.5 times the flc of the motor.

1.5 hp 230 volt FLC is 10 amps. 10 amps x 2.5 = 25 amp Breaker

Voltage drop for this motor circuit is determined by nameplate FLA and other factors. However, manufacturers motor charts show for this run of 150ft a typical 1.5 horse single phase motor needs 12 awg copper.

230 volt 1.5 hp Single Phase

14 awg copper minimum...use 12 awg copper for voltage drop at 150'

Use a 25 amp double pole common trip breaker**

if motor will not start you are allowed to go to a maximum 40 amp breaker increasing the the breaker size in standard increments by NEC table 240.6..ie.. 25 amps then 30 amps...etc...till motor holds and runs up to 40 amp breaker maximum.

Check motor/pump nameplate for thermal overload protection. IMO I would not use a motor/pump that doesnt have it.

230 volt 1 hp Single Phase

14 awg minimum...use 12 awg copper for voltage drop at 150'

Use 20 amp double pole common trip breaker**

Same procedure as 1.5 hp only max. breaker is 35 amp.

NOTE: The above figures are for farm grade water pumps much like you would find at tractor supply or northern tools etc.. these suit the application you explain. If your "suregard pump" is not suitable for the use you describe then these figures could be useless.

I was not able to find suregard pumps on the internet to compare compatibility with the above figures. If you could post the information on these pumps then we could be more positive.

Follow all manufacturer instructions

I assume you want a disconnect means for the motor. You can use cord and plug or a simple douple pole switch that will open both ungrounded conductors. The switch IMO should be good quality hp rated to match the pump you use. Of course all weatherproof compliant to NEC.

Last edited by Roger; 08-03-05 at 06:35 PM.
Old 08-04-05, 01:27 PM
Thread Starter
Join Date: Aug 2005
Posts: 19

hi & thanks for the info & help, the pump i mentioned turned out to have no head pressure, confirmed by plumber, so i returned it, it was a 2 hour round trip so i decided to shop locally, which means sears. they have a 2 hp, hi pressure sprinkler pump that i'm going to get, when i called the 800 number for the info that ibpooks asked for, they didn't have it. i dont think that you get much of a manual with any of these pumps.
what i have already done is run number 10 wire the 150 ft, it's on a double 30 breaker. maybe i can wire to a exterior box & have a plug inside, i'll be using a number 12 s o extension cord rather than anything else, what do you all think. thanks.

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