The pump is a submersible kind around 100ft down. The is rated in ~ 1.5 HP ~ 1.1 KW and also is about 3 yes old. The manufacturer"s spec sheet mentions a full load present of 9.2 A.

You are watching: Well pump drawing too many amps

1.1KW/230 gives me a number of 4.86A, or 6.88A.The energy meter reports a PF 0.92

This is single phase maker with the line voltage nominally at 230V 50 HZ. At time it might be together high as 250V.

The meter an installed against the pump shows a **constant ** 11.x 9.7 A after it is powered, which i fail come understand. I can understand a beginning surge upto the rated load current yet not 200%.

Why is this the case?

electrical energy-efficiency well-pump
boost this question
edited Apr 27 "18 in ~ 2:43
request Apr 26 "18 in ~ 4:08

30111 gold badge22 silver badges1313 bronze title
add a comment |

2 answers 2

active earliest Votes
The 1.5HP rating is the mechanically output power of the motor, no the input electrical power. The method these motors are stated is the they placed out rated power at rated current and also frequency once consuming the full-load amps. Your naive current calculation stops working to take right into account motor efficiency and power factor. In various other words, the genuine calculation goes like this:

V * ns = p / (eff * PF)

Where V is the operating voltage, i is the current, ns is the rated output power, eff is efficiency, and PF is power factor. If you resolve that equation for I, that is your expected current. Yet there is no must go through the math, since the full load existing is already detailed on the nameplate as 9.2A. So if everything is functioning right, and also the motor is placing out 1.5 HP, friend would expect to watch 9.2A.

Still, even though your expectation the 6 or 7A is wrong, that sounds like the engine is consuming an ext than the full-load current. That is unclear indigenous your post whether this is something new, or if it has been law this ever because it to be installed.

I have the right to think of three reasons you would draw an ext than rated full-load amps. Reason one is that the pump is running at a greater flow rate and lower press than it to be designed for. (It may be counter-intuitive, but centrifugal pumps and blowers consume an ext power when there is less ago pressure... Castle consume the the very least power once the earlier pressure is greatest in the no-flow condition).

The second reason is that something is faulty either in the pump or the motor. Possibly the pump pillar is rotating in the not correct direction or a bearing has actually worn out.

The 3rd reason is that the voltage is too high and the motor is just being over-driven.

See more: What Is The Correct Formula For The Polyatomic Ion Ammonium ?

If you have the make and model that the pump, and know the complete vertical head that the pump is working against, we can maybe small it under a bit much more by compare your operation pressure versus charts in the pump datasheet. It would be an excellent to know if the voltage to be 250 at the time you measured the current.