New deep well pump amps.

[The FIB]

The deep well pump at the cabin seized up after about 12 years (very little use), so last weekend my brother and I replaced it with a new one.


The install went good then I ran it for about 15 minutes on the first day, its drawing 6.1 amps, the plate on motor said running amps should be 4.8 and max service factor amps are 6.4, water is clear. The motor is a 230v-1/2HP.


The second day I ran it for another 15 minutes, amps read 5.7, getting better, but still above normal running amps and still below max S.F. amps.


I took some more readings, voltage on top with the pump running is 247v, pump is one hundred feet down, doesn't look like a voltage drop problem. Took OHM readings hot to ground on both legs is 0, hot to hot is 11.


My questions would be, should I even be worried about the higher than normal amp draw, do you think the pump is reading high because the seals are new and need to be broke in?


Any input would be appreciated, thanks.

 

[Alchymist]

A pump located quite deep will draw somewhat more power than one closer to the surface. Takes more power to lift the H2O higher. I think you are good to go.

 

[Aceman]

I wouldn't have a problem with it running in the service factor if I was using my Fluke meters to check it because I know they're accurate.

What kind of meter are you testing with?

 

[The FIB]

Thanks for the response guys, I have a tendency to overthink/overcomplicate things, the pump is made in the USA by a reputable company and comes with a 3 year warranty, so I was thinking I would take a wait and see attitude, just needed a little help convincing myself. It seems to have real good flow, so I REALLY did not want to pull it back out.

Alchymist, the pump is rated for a 220' lift so it should be OK at its 100' depth, there is also a rise of 15' in the building, plus a lateral of 70' (I don't know if they count that as part of the lift). All together I'm still within its rating.

Aceman, all the readings were taken with my Fluke T5-600, not a high end Fluke but I think we should be OK.

Thanks!

 

[wyliesdiesels]

The T5-600 and -1000 are good entry level meters..

Ive got a T5-1000 and a 381 and the T5 gets pretty close to readings taken by the 381.

 

[gungatim]

just a general assumption: if the amp draw is linear to the lift height, 4.8 at zero and 6.4 at max 220ft, somewhere around 110 ft. would be 5.6 amps, so I would say you are probably right on or pretty darn close...

 

[ard]

The pump mfg likely has published tables on draw, head, etc.

What is the static water height?

Your 'head' is not the pump depth- it is actually between the static water height and the pump depth- the higher the recovery capacity of the well, the higher that height. (Let's say you are pumping out 5GPM, and the well can recover at 10GPM. In this case the water height will basically stay at that static height. OTOH, if you are pulling 10, an the well recovers 5, the water level will drop over time)

Again, most pump/motor Mfgs will publish pretty detailed numbers/graphs/charts

 

[The FIB]

just a general assumption: if the amp draw is linear to the lift height, 4.8 at zero and 6.4 at max 220ft, somewhere around 110 ft. would be 5.6 amps, so I would say you are probably right on or pretty darn close...

What you say makes sense, the normal running amps probably start at a zero depth, the deeper the pump is set, the higher the amps.

I looked at the pump manufacturers tables, they have tables for depth-to- pressure and depth-to-flow, but didn't have anything on depth-to-amps.

 

[The FIB]

The pump mfg likely has published tables on draw, head, etc.

What is the static water height?

Your 'head' is not the pump depth- it is actually between the static water height and the pump depth- the higher the recovery capacity of the well, the higher that height. (Let's say you are pumping out 5GPM, and the well can recover at 10GPM. In this case the water height will basically stay at that static height. OTOH, if you are pulling 10, an the well recovers 5, the water level will drop over time)

Again, most pump/motor Mfgs will publish pretty detailed numbers/graphs/charts

I shouldn't have any problems with the level dropping, well's in this area are typically good producers, I haven't heard of anyone in my area running their well dry, even the shallower wells. I guess we are lucky in that respect.

I checked the original paperwork from the driller, according to his info, the well has a S.W. of 53'.

So are you saying, if the pump is at 100' and the S.W. is at 53',then I should deduct 47' from the total rise (head) number?

 

[ard]

I shouldn't have any problems with the level dropping, well's in this area are typically good producers, I haven't heard of anyone in my area running their well dry, even the shallower wells. I guess we are lucky in that respect.

I checked the original paperwork from the driller, according to his info, the well has a S.W. of 53'.

So are you saying, if the pump is at 100' and the S.W. is at 53',then I should deduct 47' from the total rise (head) number?

Yes, if the recovery rate of the well exceeds the pumps' delivery. So if you turn on your pump and it starts drawing water in, the water level will 'try' and drop- the water in the ground will then move back into the bore to replentish. How much the water height drops is actually how they rate the well's delivery capacity.

For example, my well is 400 ft deep. It was rated at 75gpm. The well driller did NOT pump 75gpm out of that to rate it. (A 5HP pump is the largest single phase pump for a 4" design, and caps out at approx 38gpm... They would have needed a three phase test pump to be able to exceed 50GPM.) So they drop down a 2HP pump, measure static height, then dynamic height after pumping for some time (like minutes to an hour, not sure), then compute the well rating.

Id say a half HP motor is barely pulling your well down, so the approximation of 50 ft of head would seem reasonable, maybe 55 or 60.

And obviously, I am not a well guy...

 

[The FIB]

Yes, if the recovery rate of the well exceeds the pumps' delivery. So if you turn on your pump and it starts drawing water in, the water level will 'try' and drop- the water in the ground will then move back into the bore to replentish. How much the water height drops is actually how they rate the well's delivery capacity.

For example, my well is 400 ft deep. It was rated at 75gpm. The well driller did NOT pump 75gpm out of that to rate it. (A 5HP pump is the largest single phase pump for a 4" design, and caps out at approx 38gpm... They would have needed a three phase test pump to be able to exceed 50GPM.) So they drop down a 2HP pump, measure static height, then dynamic height after pumping for some time (like minutes to an hour, not sure), then compute the well rating.

Id say a half HP motor is barely pulling your well down, so the approximation of 50 ft of head would seem reasonable, maybe 55 or 60.

And obviously, I am not a well guy...

Just checked the driller info again, he has 40GPM for the well, the pump is rated for 10gpm at 0', I think we should be good to go as far as capacity is concerned.

 

[mm08822]

The deep well pump at the cabin seized up after about 12 years (very little use), so last weekend my brother and I replaced it with a new one.


The install went good then I ran it for about 15 minutes on the first day, its drawing 6.1 amps, the plate on motor said running amps should be 4.8 and max service factor amps are 6.4, water is clear. The motor is a 230v-1/2HP.


The second day I ran it for another 15 minutes, amps read 5.7, getting better, but still above normal running amps and still below max S.F. amps.


I took some more readings, voltage on top with the pump running is 247v, pump is one hundred feet down, doesn't look like a voltage drop problem. Took OHM readings hot to ground on both legs is 0, hot to hot is 11.


My questions would be, should I even be worried about the higher than normal amp draw, do you think the pump is reading high because the seals are new and need to be broke in?


Any input would be appreciated, thanks.

OP, check out this info:

https://franklinaid.com/2012/06/08/column-by-column-full-load-amps-and-max-amps/

Many posts available to read..........

 

[justsam]

The deep well pump at the cabin seized up after about 12 years (very little use), so last weekend my brother and I replaced it with a new one.

I took some more readings, voltage on top with the pump running is 247v, pump is one hundred feet down, doesn't look like a voltage drop problem. Took OHM readings hot to ground on both legs is 0, hot to hot is 11.

Any input would be appreciated, thanks.

I am going to assume that you meant something closer to infinite as opposed to 0.

 

[wyliesdiesels]

I am going to assume that you meant something closer to infinite as opposed to 0.

Good catch.

 

[The FIB]

I am going to assume that you meant something closer to infinite as opposed to 0.

Yes, I meant infinite, its completely open. Zero would be a short, wouldn't it. Sorry for the confusion.

 

[ard]

Yes, I meant infinite, its completely open. Zero would be a short, wouldn't it. Sorry for the confusion.

Since the pump ran, and the current wasn't infinity- I knew the ohms couldn't be zero...