Swithching 240 Volt, 2 leg circuit

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Dave Williams

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Just replaced 240 Volt, 1.5 horse submersible pump.

Original was placed on float switch that cut both legs when storage was full, by electrician.

New is on a float switch, but well man only cuts one leg, says two leg switch to much problem.

Electricity use has increased significantly over old setup.

When only cut one leg does the other continue to consume juice, is this the reason for my increase in electric use, or do I need to look elsewhere?: :confused:
 

Jimbo

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Hard to say without seeing a wiring diagram. But try this: turn off most stuff in the house, and turn off the circuit breaker to pump. Check to see how fast the meter wheel is spinning. Turn the pump breaker back on and see if meter speeds up.

If both pumps had the same HP an service factor, you may need another electrician to figure out where the juice is going.
 

Speedy Petey

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I can tell you with 100% certainty that switching one leg as opposed to two legs of a straight 240v circuit will NOT cause any current consumption.

It has to be something else.
 

JWelectric

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When only cut one leg does the other continue to consume juice, is this the reason for my increase in electric use, or do I need to look elsewhere?: :confused:

No. There has to be a complete circuit before any "juice" is consumed.

The single pole switch installed bu the service tech is no different than the switch on your water heater. One side of the heating element is hot 24 hours a day seven days a week without consuming any "juice"
 

Speedy Petey

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The single pole switch installed bu the service tech is no different than the switch on your water heater. One side of the heating element is hot 24 hours a day seven days a week without consuming any "juice"
Perfect comparison Mike. ;)
 

Dave Williams

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Thanks

The well is on its own meter so I know the loss is somewhere in it, the only other use is occasionally through a receptacle at the breaker box.

I'll get someone to check the circuit.

Thanks for your input.

Dave Williams
 

JWelectric

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The well is on its own meter so I know the loss is somewhere in it, the only other use is occasionally through a receptacle at the breaker box.

I'll get someone to check the circuit.

Thanks for your input.

Dave Williams

In your orginal post you said
Just replaced 240 Volt, 1.5 horse submersible pump.
The difference could be in the different type of motor.
 

Bob NH

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Any of the following can cause an increase in power consumption, to different degrees.

1. You are using more water.
2. There is a leak in the pipe somewhere between the pump and point-of use.
3. The pump is less efficient (make and model of both?)
4. The pump is not well matched to the pressure requirements of the system so it is operating at a less efficient point on the curve.
5. Smaller diameter pipe, or more flow-capacity of the pump with the same pipe
6. Valve in the line is partially closed
7. Smaller tank
8. Some kind of control, such as a Cycle Stop Valve or a regulator, installed in the system
9. Wire to pump is too small so there are losses that make the pump operate less efficiently
10. Filter installed in the system
11. Higher pressure switch setting

Come back and tell us if any of the above apply to your installation.

How deep is the well and how much water is used? A 1.5 HP pump is a lot of pump for domestic use unless you have a very deep well with lots of demand.
 

480sparky

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Opening one side of a 240V circuit is opening the circuit... no power can flow (I=0).
 

Alternety

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What did that installer do with the second hot wire? Tie it to the second wire going to the pump, or something else? If the new pump motor is faulty or wiring not sealed properly, that second wire of the 220 V circuit could be supplying a 120 V "leak" somewhere through a high resistance short to ground. Opening one wire of a 240 V single phase US circuit does open the circuit but it does not remove power from the attached device. It still has 120 V applied relative to neutral or ground on the circuit. Grounding yourself and touching the motor wire on the pressure switch when the switch is open will initially provide 120 V to your body. This will rapidly drop and the final voltage will be 120 V - inductance and resistance losses in the now complete circuit at the current drawn by your body.

If it is an isolated meter and the pump is off it should be real easy to see if a power loss is occurring.
 
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