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-   -   How many watts does my well pump have? (http://www.diychatroom.com/f18/how-many-watts-does-my-well-pump-have-23539/)

diyjet52 07-11-2008 08:28 PM

How many watts does my well pump have?
 
How do you figure watts with a 230v motor?

I'm trying to figure the monthly cost to run this pump at 2 hours per day. Power company charges .087 per KWH

Another question while I'm here: One leg pulls 9.4 amps and the other leg pulls 7.8, is this normal?

Speedy Petey 07-11-2008 09:11 PM

Quote:

Originally Posted by diyjet52 (Post 138269)
How do you figure watts with a 230v motor?

How many HP?




Quote:

Originally Posted by diyjet52 (Post 138269)
Another question while I'm here: One leg pulls 9.4 amps and the other leg pulls 7.8, is this normal?

Absolutely NOT. If this is a straight 240v load either there is a problem with the motor, or there is an unsafe 120v load attached to the 240v circuit.

diyjet52 07-11-2008 09:58 PM

Quote:

Originally Posted by Speedy Petey (Post 138278)
How many HP?




Absolutely NOT. If this is a straight 240v load either there is a problem with the motor, or there is an unsafe 120v load attached to the 240v circuit.


2 HP......

Yoyizit 07-11-2008 10:11 PM

unsafe 120v load attached
 
Yes.
Can you post a schematic of how you think this is wired?

Pudge565 07-11-2008 10:21 PM

it is 1,492 Watts so 1492*2=2984 Watts per day so 2984/1000=2.984 Kilowatts per day 2.984*31=92.504 Kwh per month 92.504*.087=$8.05 per month at most.

diyjet52 07-11-2008 11:23 PM

Quote:

Originally Posted by Yoyizit (Post 138290)
Yes.
Can you post a schematic of how you think this is wired?

For right now the best I can do is describe the wiring:

The pump motor is fed from a branch circuit from my garage. It's on a 20 amp 240 breaker. Both hots go straight from the breaker to the motor. Ground is grounded at the panel then attached to a screw under the wiring cover on the motor.

Another note: I swapped the wires on the motor and re-checked amps at the panel. Nothing changed, still pulling an amp higher on the same wire. Does that rule out the motor as a problem?

After Speedy petey mentioned I have a problem I went and checked all other 240 v motors around the house (ac compressor, dryer, welder). They all varied about an amp difference between legs. I'm thinking this might be normal. Maybe my $3.99 "tool sale" amp meter is broke.

The pump motor is almost new, it only has a few hours on it. It's a Goulds.

diyjet52 07-11-2008 11:25 PM

Quote:

Originally Posted by Pudge565 (Post 138293)
it is 1,492 Watts so 1492*2=2984 Watts per day so 2984/1000=2.984 Kilowatts per day 2.984*31=92.504 Kwh per month 92.504*.087=$8.05 per month at most.

Thanks,

I found a Usage calculator, I just wasn't sure on how many Watts to enter. Here's the link:

http://www.electricity-usage.com/Ele...alculator.aspx

Speedy Petey 07-12-2008 06:23 AM

Quote:

Originally Posted by diyjet52 (Post 138304)
After Speedy petey mentioned I have a problem I went and checked all other 240 v motors around the house (ac compressor, dryer, welder). They all varied about an amp difference between legs. I'm thinking this might be normal. Maybe my $3.99 "tool sale" amp meter is broke.

I think you may have found the issue. :whistling2:

diyjet52 07-12-2008 09:27 AM

Quote:

Originally Posted by Speedy Petey (Post 138329)
I think you may have found the issue. :whistling2:

Are the amp meter at lowes worth getting? If not what's a good brand to get without going bankrupt?

Yoyizit 07-12-2008 09:45 AM

The extra amp might be found going into the neutral, and this might be OK according to the NEC. Otherwise there might be other current paths.

I would pursue this problem until you're satisfied you've accounted for all the readings, more for safety than for motor lifetime.

J. V. 07-12-2008 11:42 AM

I would not consider a 1 amp difference on a motor reading as a problem.
Motors are induction loads and all motors are not created equally. One extra turn of magnet wire at the factory is all it would take for the imbalance. If your meter has a ohm scale, measure the motor windings. The ohm readings should reflect the variation in current. Put another way, the ohm readings will not be the same, just as the current reading is not the same.

diyjet52 07-12-2008 12:03 PM

Quote:

Originally Posted by Yoyizit (Post 138374)
The extra amp might be found going into the neutral, and this might be OK according to the NEC. Otherwise there might be other current paths.

I would pursue this problem until you're satisfied you've accounted for all the readings, more for safety than for motor lifetime.

You're right, the neutral wire has about 1.3 amps on it. You're saying this is ok? Doesn't make a whole lot of sense to me, I never would have thought to check the neutral.

Man, this thread has done made me about 15% more smarter :001_unsure:

Speedy Petey 07-12-2008 01:02 PM

Quote:

Originally Posted by Yoyizit (Post 138374)
The extra amp might be found going into the neutral, and this might be OK according to the NEC.

Quote:

Originally Posted by diyjet52 (Post 138413)
You're right, the neutral wire has about 1.3 amps on it. You're saying this is ok? Doesn't make a whole lot of sense to me, I never would have thought to check the neutral.

WHAT neutral??? A 230v circuit for a motor does NOT have a neutral nor does it need one.

Is there a neutral run with the two hot conductors?
Is anything else on this circuit?

We still do not have all the correct information.

diyjet52 07-12-2008 01:16 PM

Quote:

Originally Posted by Speedy Petey (Post 138431)
WHAT neutral??? A 230v circuit for a motor does NOT have a neutral nor does it need one.

Is there a neutral run with the two hot conductors?
Is anything else on this circuit?

We still do not have all the correct information.

I measured the 1.5 amps on the main neutral wire in the panel. I had all other breakers turned off.

I'm getting ready to run out to lowes, let me check it all again with a good amp probe and i'll get back to you.

Speedy Petey 07-12-2008 01:57 PM

Is there a neutral run to the pump? If so WHERE is is connected?


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