# Well pump electric usage and water usage

Discussion in 'Plumbing Forum, Professional & DIY Advice' started by joseph skoler, Oct 22, 2021.

1. ### joseph skolerMember

Joined:
Jan 14, 2018
Location:
Sullivan County, NY
I have a Flume water monitor on my well water meter and Emporia Vue electric monitor on my well pump.

I am hoping someone can help me better understand the data I’ve collected.

I ran a test early this morning: Used 13.65 gallons of water which caused the well pump to kick on for less than 2 minutes and use 1507 watts of electricity.

I have a CSV, a 62 gallon pressure tank in the well house and a 62 gallon secondary pressure tank (no electric hookup -- just a holding tank) about 200' feet away in a workshop.

I understand there are many, many factors involved, but I’m hoping someone there has experience with this and can help me better understand.

What can be understood from this data?

Thanks!

Thank you,

Joseph R. Skoler

joseph@nycequities.com

646-201-5311

2. ### valvemanCary AustinStaff Member

Joined:
Mar 15, 2006
Occupation:
Pump Controls Technician
Location:
Lubbock, Texas
Looks like you may have a leak of less than 1 GPM somewhere. Did you use the 13 gallons of water or did it just leak out?

4. ### joseph skolerMember

Joined:
Jan 14, 2018
Location:
Sullivan County, NY
I used it. Morning bathroom.

Other times (overnight) usage was 0.

I'm curious if there's something we can learn from the power usage (i.e., the well pump running) because of that amount and rate of draw.

5. ### Reach4Well-Known Member

Joined:
Sep 25, 2013
Location:
IL

If electric usage, compare KW to MPH in a car. If I record 30 MPH and the next minute 60 MPH, I don't add those to get 90.

On the other hand KWH would compare to miles. If I drive 0.5 miles one minute, and 1.0 miles the next minute, then that does add to 1.5 miles.

So what are your numbers? Maybe watt-minutes, and you would divide by 60,000 to get kWh -- what you are billed on?

6. ### valvemanCary AustinStaff Member

Joined:
Mar 15, 2006
Occupation:
Pump Controls Technician
Location:
Lubbock, Texas
A 62 gallon size pressure tank holds about 15 gallons of water. With two of those there should be 30 gallons to use before the pump comes on. So, apparently the tanks where only half full when you started using water and you only got 13 gallons before the pump came on. So, the 2 minutes of run time should have been to refill the 30 gallons in the tanks, not to supply 13 gallons. Depends on where your flow meter is?

7. ### fitter30Well-Known Member

Joined:
Feb 2, 2020
Occupation:
Retired service tech
Location:
Peace valley missouri
14 minutes in a row using less that 1 gpm a minute. Your flume device what water meter do u have? Did u ever check gpm flow to wifi reading. Energy monitor is it hooked to just the pump or does it break down it individual breakers? Plug in a hair drier or electric heater measure watts.

8. ### fitter30Well-Known Member

Joined:
Feb 2, 2020
Occupation:
Retired service tech
Location:
Peace valley missouri
Check both energy devices 5 gallon bucket measure gpm and time it let it run for 5 minutes.
Electric use a hair drier or electric heater to check watts used.

9. ### Reach4Well-Known Member

Joined:
Sep 25, 2013
Location:
IL
I presumed a faucet was opened part way for purposes of doing this test.

10. ### joseph skolerMember

Joined:
Jan 14, 2018
Location:
Sullivan County, NY
Is there a way to determine how much water is in a pressure tank by knowing the water pressure at the tank input?

11. ### joseph skolerMember

Joined:
Jan 14, 2018
Location:
Sullivan County, NY
I had a bathroom sink going and a flush, so I think 1gpm for 14 minutes would make sense.

I don't remember the meter specs. I never confirmed the accuracy.

Energy monitor is connected to a panel and I am 100% confident nothing else was drawing any current at the time.

I think the way to interpret this is:

1) 14 gpm for each of 14 consecutive minutes
2) Well pump kicked on due to the pressure at the tank dropping below 40psi at minute 9 and used 379 watts in that minute
3) Well pump stayed running for some part of minute 10 and used 1128 watts until it shut off because tank pressure reached 70psi

I supposed I'm curious if we can determine how much water was pumped by the pump which used 1507 watts. We can also estimate that the pump ran for between 60 and 90 seconds, so we can roughly calculate the flow rate of the pump also.

12. ### joseph skolerMember

Joined:
Jan 14, 2018
Location:
Sullivan County, NY
Exactly.

13. ### Reach4Well-Known Member

Joined:
Sep 25, 2013
Location:
IL
Pretty much. Know that when the water pressure exactly matches the precharge, the tank contains zero water, and the (tank capacity) of air. As water pressure increases, the air compresses according to Boyle's law, so you can compute the air volume. Water volume is (tank capacity) - (air volume).

When using Boyle's law, express the air pressures in (absolute pressure), which is (gauge pressure)+(atmospheric pressure).

14. ### joseph skolerMember

Joined:
Jan 14, 2018
Location:
Sullivan County, NY
Super cool, but juuuussst above my pay grade.

But I'll take a shot at it.

40 psi precharge (this is assumed, I didn't check).

60 psi on gauge.

Atmospheric pressure: 14.7 (also, assuming here)

So (I think):

When gauge psi = 40, water amount = 0

V1 = 62 gallons
P1 = 57.7 psi (40+14.7)
V2 = Volume of air when gauge reads 60 psi
P2 = 77.7 psi (60+14.7)

(V2 = P1 • V1/P2)

Amount of air when gauge reads 62 psi =

40 * (57.7/77.7) = 29.7

Amount of water when gauge reads 60 psi = 32.3 gallons (62 - 29.7)

Reach4 likes this.
15. ### Reach4Well-Known Member

Joined:
Sep 25, 2013
Location:
IL
Instead of 40 psi, you would want to use the 38 psi -- the precharge pressure, unless your precharge is 40.
I may go through that in more detail later, when I am more alert. I am pretty sure the answer should be closer to 20 gallons of water.

Also, this is a simplification that presumes that the diaphragm is perfectly limp. If we had to account for the diaphragm getting tight, we could not really do that. So we ignore that one.

16. ### Reach4Well-Known Member

Joined:
Sep 25, 2013
Location:
IL
62* (57.7/77.7) = 45.4

Water = (62-45.4) = 16.6 gallons.

17. ### fitter30Well-Known Member

Joined:
Feb 2, 2020
Occupation:
Retired service tech
Location:
Peace valley missouri
Consumed electrical energy is expressed in Watt-hour (Wh) or KWh, not in watt or Kw. 1/2 hp capacitor start induction run motor approximately pulls 1800 watts starting 600 running. All your chart tells me towards the last few seconds of 8 minutes the pump started and ran for one m after 7.51 gallons were discharged. With two ex tanks and csv doesn't make sense if they were working correctly.

18. ### Reach4Well-Known Member

Joined:
Sep 25, 2013
Location:
IL
Maybe something like the pump draws 1200 watts, and it ran during the last 19 seconds of one minute and the first 56 seconds of the next minute.