Solving the Mystery of the 4-5 Amp Draw on a 0.5 HP Pump

  • Thread starter Thread starter Evil Bunny
  • Start date Start date
  • Tags Tags
    Amp Mystery Pump
AI Thread Summary
A coworker is experiencing a puzzling 4-5 amp draw on a brand new 0.5 HP well pump, which should theoretically draw only 1.55 amps at 240V. The discrepancy may be due to the power factor, particularly in inductive loads, where the phase shift between current and voltage affects the actual power consumed. This phase shift can lead to higher amp readings despite the lower expected draw. Compensating for this issue can be achieved by connecting a capacitor in parallel with the pump. Understanding power factor and efficiency is crucial in resolving this mystery.
Evil Bunny
Messages
241
Reaction score
0
A coworker has a well pump that is a 0.5 horsepower, brand new, no issues...

He says the normal amp draw is 4 to 5 amps.

This is puzzling because it is a 240V pump and the math works out to (746/240 = 3.1/2 = ) 1.55 amps.

What is going on?
 
Engineering news on Phys.org
maybe it's the, i don't know English term for it, phase shift between current and voltage. E.g. if the current is 90 degrees off phase, the power (given by integral of voltage times current over entire cycle) will be 0 no matter the current. It tends to happen with inductive loads. It can be compensated for by connecting a capacitor in parallel.

Read this article:
http://en.wikipedia.org/wiki/Power_factor
 
Yep... I was forgetting all about power factor and efficiency. Don't I feel stupid now...
 

Thread '3-terminal device external modeling'

Very basic question. Consider a 3-terminal device with terminals say A,B,C. Kirchhoff Current Law (KCL) and Kirchhoff Voltage Law (KVL) establish two relationships between the 3 currents entering the terminals and the 3 terminal's voltage pairs respectively. So we have 2 equations in 6 unknowns. To proceed further we need two more (independent) equations in order to solve the circuit the 3-terminal device is connected to (basically one treats such a device as an unbalanced two-port...
View full post »

Thread 'Two capacitors, etc.'

suppose you have two capacitors with a 0.1 Farad value and 12 VDC rating. label these as A and B. label the terminals of each as 1 and 2. you also have a voltmeter with a 40 volt linear range for DC. you also have a 9 volt DC power supply fed by mains. you charge each capacitor to 9 volts with terminal 1 being - (negative) and terminal 2 being + (positive). you connect the voltmeter to terminal A2 and to terminal B1. does it read any voltage? can - of one capacitor discharge + of the...
View full post »

Similar threads

Solving Power Delivery Issues in a 5V Series Circuit with a 1.5V Rated Relay
Replies
12
Views
3K
Engineering I’m having second thoughts about my job position. How can I proceed with it?
Replies
13
Views
5K
Solve Normal Distribution Homework with Mean 5, Standard Deviation 4
Replies
1
Views
4K
A Shinichi Mochizuki's ABC Conjecture and Replication Crisis in Maths
Replies
33
Views
7K
Why can’t decay heat be harnessed to safely shutdown a nuclear reactor?
Replies
14
Views
10K
Challenge Math Challenge - December 2018
2
Replies
67
Views
14K
Exhaust and engine accoustics for asthetics and performance
Replies
2
Views
7K
Who is the Killer at the Beach Barbecue?
Replies
9
Views
5K
Terrell Revisited: The Invisibility of the Lorentz Contraction
4
Replies
184
Views
22K
Where to from here? (I need a mixture of academic and life guidance I think )
Replies
12
Views
3K

Hot Threads

Recent Insights

Back
Top