How To Choose A Well Pump Breaker Size: A Full Guide

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The circuit breaker is a self-destructive system to protect appliances like well pumps. Normally, it’s a good idea to hire a professional. But luckily, this task can be completed all by yourself!  

How do you select a good well pump breaker size? 

Circuit breakers prevent extra amps from running through your pump. So you’ve to choose breakers according to the amperage of the pump. For example, a 0.5 HP well pump uses around 7 amps to operate properly. So, it requires a 15 amp circuit breaker. So, installing a circuit breaker that has 2x more amp capacity is a safe play. 

Anyways, that was a short preview of the discussion. Here, we’ve provided multiple charts and explained them in easy words. 

Let’s not roam around any longer and head right in- 

How Does A Circuit Breaker Work In A Well Pump? 

Knowing how circuit breakers work will give you an advantage in choosing one. Similarly, it’ll help you realize what breaker size you need for a 40-gallon electric heater

A circuit breaker is planted to stop extra electricity from entering the system. Extra electricity causes overheating in the system; gradually killing it. 

Circuit breakers have thin wires which can only endure a certain level of heat. In case of excessive electricity, it melts down due to overheating. It cuts off the connection as a result. This is called tripping. 

Now, you may wonder why not use a small-sized breaker and be done with it? Well, if it trips frequently, it can damage your pump. 

Also, that’s why you can’t use a 15 amp switch in a 20 amp circuit.

On the other hand, a high-amperage circuit breaker is also bad. Although, it is pretty self-explanatory. A bigger circuit breaker will allow more electricity to pass through the system and poof! The motor pump is now dead. 

Proper Breaker Sizes For Well Pumps 

Till now we’ve discussed how circuit breakers keep electronics safe. But now we’ve to add an extra factor to this equation. 

A well pump needs extra force to get started. In other words, it requires extra electricity flow to properly start spinning. 

For example-

If you put a 7 amp circuit breaker for a 7 amp pump, it’ll get tripped. Because it draws more than 7 amps to start itself. 

Now, let’s put a 15 amp circuit breaker for a 7 amp pump. Obviously, it’ll let the extra electricity go through it which will start the pump. 

It’ll then keep drawing 7 amps during the rest of the operation. It can also draw more amps like 10-12 amps while under maximum load. 

Pumps Under Full Load

Most of the well pumps have 220-240 volts. But the amp draw varies from model to model because of different horsepower. 

A full load means when the pump is working with full efficiency. The pump will draw a specific amount of power while executing a standard operation. 

To save your time, we’ve added a table to help you out. These are the required circuit breakers for pumps that are under full load:

Well Pump (HP) Volts (V) Wattage (W) Amps Circuit Breaker (Amps) 
0.5 HP110V 670W10A15A
0.5 HP230V 670W5A15A
0.75 HP230V 940W6.8A20A
1 HP 230V 1210W8.2A25A
1.5 HP230V 1770W10.6A30A
2 HP230V 2025W12A30A
3 HP230V 3000W15A40A
5 HP 230V 4900W25A50A

As you can see-

The required circuit breakers have a much higher amp rating than operating amps. This way, the circuit breaker won’t trip easily even if there’s a sudden surge in electricity. 

The pump’s horsepower also affects the total power draw. For residential uses, ½ HP or ¾ HP is good enough

Pumps Under Maximum Load

But there’s another benefit of having a higher amp-rated circuit breaker. It allows the pump to achieve higher efficiency by letting it draw more power. 

Here are the required circuit breakers for pumps under maximum load- 

Well Pump (HP) VoltsWattage Amps Req. Circuit Breaker (Amps) 
0.5 HP110V960W12A15A
0.5 HP230V 960W6A15A
0.75 HP230V 1310W8A20A
1 HP 230V 1600W10.4A25A
1.5 HP230V 2280W13.1A30A
2 HP230V 2555W16A30A
3 HP230V 3400W19A40A
5 HP 230V 5500W30A50A

So, even under maximum load, the pumps draw a lesser amp than the limit. And that’s how the circuit breaker successfully prevents any kind of damage. 

Sometimes you may not have access to the pump information. In those cases, you have to read the amperage first. 

To calculate the amperage you’re going to need a multimeter. With that, you don’t have to hire a professional and you can also calculate amps by yourself

Also, here are our top picks regarding the multimeter:

Product 1 
Product 2 

Now, you can easily get whichever you like and get started! 

If all these seem too hard or bothersome, just give your mechanic a call! 

FAQs

Question: Is a well pump 110V or 220V?
Answer: Most household pumps are 220-volt single-phase motors. However, it’s possible to get some old 110-volt pumps. Also, bigger pumps require 3-phase motors and more voltage. 

Question: How many amps do a 1.5 HP well pump draw?
Answer: 1.5 HP well pumps are power-hungry as they are very huge. Most of them will draw 13-17 Amps depending on workload. 

Question: What size breaker do I need for a 220V pump?
Answer: Almost all the motors require 220-volt motors. So, the horsepower of the pump is the factor. For example, ½ HP pump needs a 15 amp breaker. But the ideal circuit breaker will be 25 amps for a 1 HP pump. 

Conclusion 

Anyways, that was everything we could explain about how to choose a well pump breaker size. We hope it has satisfied your curiosity and now you have a better idea. 

Good luck on getting the appropriate pump breaker. Have a nice day!

Richard Allen