Blog posts tagged with 'compatability'

General Electric’s Magne-Blast Product Line and Interchangeability

The General Electric Magne-Blast product line was produced with a wide array of shapes, sizes, and ratings. Finding interchangeable breakers can be simplified once you break the line down to a few simple rules.

How to Determine if a GE Magne-Blast Breaker is Interchangeable

Single Coupler vs. Double Coupler

The secondary coupler or secondary disconnect is a device/plug that carries the power that controls the breakers opening and closing circuits. The original breakers are equipped with 2 round, 7 pin couplers that mount on each side of the mechanism. The newer breakers have a single square coupler with 16 pins that mounts on the left-hand side (as you face the breaker). These two breakers are not interchangeable.

Round style double couple Magne-Blast breaker.

Square style single coupler Magne-Blast breaker.

Solenoid vs. Stored Energy

Older breakers are equipped with a large closing solenoid that closes the breaker, this mechanism type typically has an “MS” designation, like MS-5, MS-7, MS-10B1, or the most common designation MS-13. Newer breakers are equipped with a spring charged/stored energy mechanism, most commonly, the ML-13. This mechanism uses a motor/gearbox to compress springs that are released to close the breaker.

The primary advantage of the stored energy mechanism is that it draws much less current to close the breaker. These breakers have a limited interchangeability. More modern ML-13 breakers can sometimes be used to replace old MS style breakers. When produced at the factory, these replacement breakers will have a “C” at the end of the model number (e.g. AM 4.16-250-6C). Minor changes will also need to be made in the cell wiring when using this replacement because of the decreased power that it takes to close the breaker.

Magne-Blast breaker with MS mechanism.

Magne-Blast breaker with ML mechanism.

Frame Size/Voltage/MVA Rating

The next thing to look for is the MVA rating of the breaker. This is designated in the model number after the voltage rating e.g. AM 4.16-250-6C, is a 250 MVA rated breaker.

The smallest of the product line is the 18-inch wide 50/75 MVA breakers. Designated as either AM 5-MVA or AM 4.16-MVA, these breakers all had one of various vintage MS style solenoid mechanisms. They are available in 600-amp and 1,200-amp frames and are backwards compatible. For example, an AM 4.16-75 1,200-amp breaker can be used in place of an AM-5-50, but not the other way around.

The next step up are the 100/150/250/350 MVA breakers. These are built on slightly wider, 26-inch frames and are very common in commercial and industrial facilities. They have the same limited backwards compatibility of ML-13 to MS-13 mechanisms outlined above and all but the 350 MVA have a backwards compatibility of MVA, as well. In other words, a 250 MVA can always be used in place of a 150 MVA but not the other way around. The 350 MVA’s are built on a taller frame and are unique.

The larger 36-inch-wide breakers cover both the 7.2 kv and 13.8 kv range which are not interchangeable with each other, but generally carry the same interchangeability of their smaller 5kv brethren. The exception comes in the 750 MVA frames. The original 750 MVA (e.g. AM 13.8-750-2) is on a much taller frame than the 500 MVA or below breakers and is commonly known as a “tall boy.” Its added height is unique. However, GE did make a replacement later in production that is designated with an “L” at the end of the nameplate, AM 13.8-7505HL, which indicates a shorter lower profile breaker that was factory modified to fit into the ‘tall boy” cell.

The final breaker, the AM 13.8- 1000 is unique and not interchangeable with the others. There are two basic versions the AM 13.8 100-3H and 4H. The “3H” is commonly called the humpback breaker because the box barriers and arc chutes are taller in the back. The “4H” has smaller arc chutes and is interchangeable with the “3H”, but again, not the other way around.

Frame Size

600/1200/2000/2500/3000/3800

Always make sure that breakers are replaced with replacements of the same frame size or extensive damage could result.

Need Help Finding Interchangeable Breakers?

Still confused? We can help. Take a photo of your nameplate and contact us or just go to m.npeincom and follow NPE On The Go to get all of the information we will need to quote you a replacement.

Trying to find a way to extend the life and reliability of your GE Magne-Blast switchgear instead of looking for a replacement? Learn more about how NPE’s bottle repotting program can be just what you need. If you need help identifying Magne-Blast circuit breaker designations, read this post to find out where to look.

Are Eaton, Westinghouse, Square D, and Cutler Hammer Breakers Compatible?

The search for old or obsolete circuit breakers isn’t always easy. Many factories and government or commercial facilities operate on electrical equipment that is no longer supported with new parts, which means you need to either find a remanufactured air or vacuum circuit breaker or aftermarket breaker parts that are a match for your equipment.

There are several companies that have manufactured breakers in the past century and beyond, but you typically can’t swap out one competitor’s breaker parts for another’s. However, there are some instances where one brand of breaker is nearly identical. Westinghouse and Eaton are two such examples.

Circuit breaker with Eaton nameplateCircuit breaker with Westinghouse nameplate

Why Does Eaton and Westinghouse Have Compatible Breakers?

The answer is simple: the same company owns the production rights for both Eaton and Westinghouse. Westinghouse had a low-voltage air circuit breaker line. The company sold the rights to this product line to Square D, which then sold it to Eaton Corporation. As a result of rights ownership, there are nearly identical breakers with four different nameplates on them:

  • Westinghouse
  • Square D
  • Eaton
  • Cutler-Hammer

These breakers can be compatible with each other despite the different nameplates, as certain models are largely the same aside from some upgraded electronics.

Circuit breaker with Square D nameplateCircuit breaker with Cutler Hammer nameplate

Find Old and Obsolete Eaton and Westinghouse Breakers

While you now know that Eaton breakersWestinghouse breakers, Square D breakers, and Cutler-Hammer breakers are largely compatible, you still need to find the exact models you need for your facility. At NPE, we have amassed and refurbished old electrical equipment, including breakers and aftermarket parts for Eaton, Westinghouse, and more.

Ready to find the right breaker parts for your facility? Submit information about what you need on our NPE on the Go mobile site or contact us today to talk to one of our experts about finding the rights solution for your needs.