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What Circuit Breakers are Compatible with Cutler Hammer (Types and Voltages)

In this article, I will help you to understand which Circuit Breakers are compatible with a Cutler Hammer.

Being a certified electrician, I have experience in regularly dealing with Circuit Breakers. The compatibility of circuit breakers is crucial when doing any electrical work. Using compatible circuit breakers with a cutler hammer is mandatory to guarantee your circuit’s and electrical appliances’ safety; getting it wrong can lead to electrical fires.

In general, the following circuit breakers are compatible with a cutler hammer CB:

  • Low Voltage Circuit breakers — Popular in residential and business facilities – are divided into two categories: Moulded Case Circuit Breakers and Miniature Circuit Breakers
  • Medium Voltage Circuit Breakers — are deployed in 120V and 240V for medium levels
  • High Voltage Circuit Breakers — serve as a protection device for the transmission and distribution of electricity.
  • Thermal Circuit Breakers — also called overload circuit breakers and are found in almost all circuit breakers.
  • Magnetic Circuit Breakers — highly modernized replacement for regular circuit breakers
  • Eaton, Square D, Westinghouse, and cutler hammer circuit breakers are compatible.

We will go into detail below. Let’s begin.

Categories of Circuit Breakers Compatible with Cutler Hammer Breakers

Cutler hammers are old, and it’s a mission to find compatible circuit breakers. However, the information below will help you find circuit breakers that are compatible.

Low Voltage Circuit Breakers

Low-voltage circuit breakers are very popular. They are in various residential apartments, homes, and commercial buildings.

Low-voltage circuit breakers can secure the entire circuit or individual electrical appliance from a power or voltage surge.

circuit breakers
Video | GalcoTV

There are two categories of low-voltage CBS, MCCBs, and MCBs.

MCCBs – Moulded Case Circuit Breaker

MCCBs are used in any environment. They prevent the adverse effects of short circuits, ground faults, and thermal overloads via thermomagnetic and EM mechanisms.

MCBs – Miniature Circuit Breaker

MCBs and MCCBs are similar in almost all aspects and applications. However, the main difference is in their capacities. Check below:


Current – rated under 100 amps


Current rating – up to 2500 amps

Medium Voltage Circuit Breakers – MVCB

Medium Voltage Circuit Breakers are deployed in 120 and 240 voltages for medium-level applications.

They are also common and can be found anywhere from home wiring to business wiring. Additionally, medium-level circuit breakers are in the electrical lines of railways.

medium-level circuit breakers
Video | cpswitchgear

High Voltage Circuit Breakers

These circuit breakers are used as safeguard devices and are more prevalent in electricity transmission and dissemination/distribution.

They protect the transmission lines from current faults and damages, an imbalance, and any other potential fault in the transmission and distribution of electricity.

Thermal Circuit Breakers – Thermal CB

Thermal CBs are in most circuit breaker boxes. They are also called overload circuit breakers, fuses, and heat-triggered circuit breakers. They function to trip the current flow at a designated temperature. They consist of a metal strip with a couple of pieces of metal welded on.

Magnetic Circuit Breakers

Magnetic CBs are the modern replacement for the genuine versions of trip circuit breakers.

They showcase Impressive technological features and are modern. They utilize a multi-dimension electromagnetic coil that switches its polarity continuously. And they are also compatible with a cutler hammer.

Eaton Circuit Breakers

eaton circuit breakers
Video | EatonVideos

The following are identical breakers with different nameplates on them; hence they are all compatible and can be used interchangeably despite having different names.

  • Westinghouse
  • Square D
  • Eaton
  • Cutler-hammer

However, despite the similarity of the breaker models, you still need to use exact models.

The Eaton breaker is compatible with the Cutler-Hammer on all models. It’s imperative to know that the Cutler-Hammer is not compatible with any Siemens model. In contrast, Murray breakers are identical and can be used with the Cutler-Hammer.

Experiments reveal that you can use Siemens and Murray breakers interchangeably. However, Murray and Square D breakers work similarly. Additionally, they have a robust design and are easy to install. Another advantage is that they are reliable and safe.

Functions of Circuit Breakers

All circuit breakers are designed to safeguard electrical circuits and transmission lines in various forms like fuses. The breaker cuts the power source to the circuit automatically when the power trips. That way, damages to house Equipment and wiring are curtailed.

The circuit breaker then remains tripped until the overload conditions reassert.

Alternatively, operators can reset the overhead conditions manually, via the small button on the breaker.

Technicalities of Cutler Hammer and Other Circuit Breakers

Before you start looking for a circuit breaker compatible with your cutler hammer, you need to understand the various terminologies and properties of circuit breakers. Not knowing these definitions harms circuit breaker wiring and the operators.

The following are the basic technicalities of circuit breakers you should know:


You must know the voltage requirement of your circuit breaker before even considering fetching a compatible CB.

Various circuit breakers operate within a given limit. Exceeding such limits can result in malfunctions in the circuit. So, voltage mathematics and integrations are vital features to consider before choosing a circuit breaker. They ensure that a cutler hammer or any other circuit breaker supplies sufficient power to the equipment or appliances. (1)

Current Rating or Amps

A higher amps rating in a circuit breaker helps offset the effects of overheating in an electrical circuit or power system.  

In the event of an electrical fault, most fuses heat up. However, they should heat up within their allowable limits. If they exceed their allowable levels, they might gape open and harm the circuit or the appliance.

In contrast, circuit breakers don’t heat up appreciably when electrical faults occur. Hence, they oftentimes close without even gaping or opening, even if the voltage surge is great.

Nonetheless, I suggest you select a circuit breaker for approximately 120 percent of the required load.  

Moisture & Corrosion

You need to protect your cutler hammer or any other circuit breaker from moisture which can ultimately corrode your CB. That way, your device will function optimally.

Treat your circuit breaker with lubricants, rust inhibitors, or mold treatments to ensure better performance. (2)

Conductive Contact Plates of CBs and Cutler Hammer Compatibility

Ensure that the replacement circuit breaker is compatible with your cutler hammer panel. All cutler hammer replacement CBs have two conductive plates; stationery and moving or mobile conductive plates.

The stationary conductive plate is called the bus bar, and the mobile plate is known as the trip bar. The bus bar ferries 120V of DC (direct current) while the trip bar carries 24V DC. The trip bar attaches to the circuit and it trips turning off the breaker when overloaded or damaged.

Wrapping Up

Cutler hammer CBs, despite being old, still have compatible circuit breakers that are rather difficult to find. So, whenever you want to replace or add circuit breakers to a cutler hammer panel, go for any of the available options outlined in this guide. Make sure you understand the voltage and ampere ratings of the cutler hammer before looking for a replacement circuit breaker as faulty or wrong ampere and voltage values can jeopardize your circuit components.

Circuit breakers are crucial components that you cannot miss in your electrical circuit to protect your appliances and wiring from short-circuit and overload issues.

I hope this guide helps you find a circuit breaker compatible with your cutler hammer.

(1) mathematics – https://www.britannica.com/science/mathematics
(2) mold treatments – https://www.nytimes.com/2020/06/04/parenting/

Video References




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About Sam Orlovsky

AvatarCertifications: B.E.E.
Education: University Of Denver - Electric Engineering
Lives In: Denver Colorado

Electrical engineering is my passion, and I’ve been in the industry for over 20 years. This gives me a unique ability to give you expert home improvement and DIY recommendations. I’m not only an electrician, but I also like machinery and anything to do with carpentry. One of my career paths started as a general handyman, so I also have a lot of experience with home improvement I love to share.

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