General Electric produced a very popular line of medium voltage (2.3kv-15kv class) circuit breakers over a 30-year timespan with literally tens of thousands of units in service across the U.S., Canada, and other areas. This product line, known as the Magne-Blast or AM breaker, has been upgraded over the years with improvements and life extensions to add even more value to the customer.

One of the maintenance items that needs to be addressed periodically is what the industry calls the “Raise Lower Mechanism.” This is a mechanism that lifts the breaker from ground level and assures proper alignment and connection to the primary disconnects on both the line and load side.

Maintaining Raise Lower Mechanisms for Your Circuit Breakers

There are several versions of this mechanism that need to be identified properly when service is needed. First, we will address the two most common mechanisms, the “Cast” and “Fabricated” or “Fab’d” mechanisms. GE classifies these mechanisms into two groups depending on the width of the switchgear cabinets they are in because they also include the shutter and connecting chain. GE identifies the Cast Mechanisms as either M26H or M36H because the cabinets they go in are either 26” or 36” wide. The fabricated design is simply designated as M26 and M36.

There is a well-known table in a GE publication that details the supposed application of these devices with particular breaker models and frame sizes. However, we have found both discrepancies in actual field applications as well as contradictions within the table itself. See the Illustration 1 Cast vs Fab mechs pdf for reference.

The easiest way to identify which mechanism you may have (they are not interchangeable), is by looking at the housing at the top of the mechanism that contains the gears. The cast style is obviously heavier duty, thicker, and has pit marks from the sand that was used to sand cast the original parts. The fabricated style is built with plate steel that is lighter duty and welded together.
See Illustrations 2 and 3 for reference.

NPE regularly stocks both of these mechanisms. They are completely rebuilt and ready to install for those “unscheduled outages” and we can even take your damaged or worn out mechanism in for a core rebate. For customers that want to rebuild the mechanisms themselves, we offer both cast bushing kits and fabricated bushing kits and years of experience and expertise to help you along the way.

Raise Lower Mechanism Exceptions

While these mechanisms comprise 90% of what is found in the market, there are some exceptions that should be noted.
The first mechanism is designated in the first illustration with the “HH” suffix. These mechanisms will be found in the largest of the Magne-Blast product line, particularly in the 1000 MVA breakers. See 7A in Illustration 1 for reference. They are the heaviest duty mechanisms and have two vertical screws to lift these frames into place.

On the opposite end of the spectrum, the smallest Magne-Blasts made are the 50 and 75 MVA class and are built for 18”-wide switchgear. These cells utilize a single lifting screw mechanism mounted on only the right side of the cell.

The last group of mechanisms are the oldest versions made for the AM 5 and AM 15 versions of the Magne-Blast line that utilize a double secondary coupler. While not many of these breakers are left in service, there are designs for updated/retrofitted breakers that still use the old switchgear. This last set will have the double vertical screw on both sides, similar to the “HH” version, except that these are much lighter duty. When replacing these, you will need to know if the motor that operates the lift is mounted in the front of the cell or all the way in the rear.

Raise Lower Mechanism Aftermarket Parts to Help Keep Switchgear Going

In addition to Raise Lower Mechanisms, NPE manufactures and stocks many of the common parts that you will need to keep your switchgear running. Raise lower motors, motor clutch parts, and bearing kits are all the things you will need to properly operate and maintain your equipment. You can find these parts in our Aftermarket Parts Store on our website.

• AM 4.16 -350 3000 Amp Shutter (Cell)
• AM Motor Coupler
• AM Raise Lower Mech Bearing and Bushings Kit (Cast)
• AM Raise Lower Mech Bearing and Bushings Kit (Fabricated)
• AM Raise Lower Motor (120 AC/125 DC), with Switch
• AM Raise Lower Motor (120 AC/125 DC), without Switch
• AM Raise Lower Motor (220 AC/250 DC), without Switch
• AM Raise Lower Motor (220 AC/250 DC), with Switch
• AM Raise Lower Motor Base Plate

This may seem complicated, but at NPE we face these questions every day. Our knowledgeable staff has the expertise to walk you through the various steps to identify what you have. Contact us online, give us a call, or send us an email with pictures of the nameplate if available and we will help you get the right parts, at the right price, right now!

General Electric produced tens of thousands of Magne-Blast breakers in various sizes.

While most maintenance programs focus on rebuilding the original air breakers or retrofitting them to a more modern vacuum technology, there are other components to the system that need to be addressed to maintain safety and reliability.

Why Magne-Blast Bottles Need to be Repotted

The main component that needs to be addressed is the “bottle,” the critical link between the draw outcircuit breaker and its connection to the line and load side buss. The bottle consists of a porcelain cylinder mounted in a cast aluminum plate that is aligned and attached to the switchgear cabinet. Within that bottle is a silver-plated copper “tulip” that the line and load side conductors mate with for a solid reliable connection.

That connection is mounted in a filler material and supported by potting material that was originally designed to fill the upper void in the bottle and hold it in place for proper alignment. However, that material, commonly described as a tar pitch like filler, dries out and cracks over time. This allows moisture, dirt, and other contaminants into the bottle that cause that old reliable mating connection to loosen and eventually fail.

Those failures can be catastrophic, causing untimely loss of production and collateral damage, and can occur regardless of the care and maintenance of the breaker and the rest of the system. The question then is, “How do I maintain the reliability of this system”? Should I spend the capital for upgrades and replace the whole system?”

The answer is simple: Call NPE. We have the material and experience to eliminate this issue and help you extend the life of your Magne-Blast switchgear through our special repotting process.

NPE’s 8 Step Procedure: 

1.      Examine the bottles in a fixture and conduct a wipe test to assure that they are candidates for rebuild.

2.      Remove the outdated “tar pitch” potting right down to the filler.     
3. Re-align the connecting tulip and lock it in place so it doesn't move and cause future failures.
4. Secure the joint between the copper and seal.
5. Insulate the buss with modern shrink tube insulation.
6. Replace the old potting with a new 2 part system that is thermally stable which will last far into the future.
7. Clean and silver plate all mating surfaces to increase conductivity at critical joints.
8. Re-test alignment and conductivity to assure a quality trouble-free replacement in the field.

Sound simple? The devil is in the details and NPE focuses on details. This whole procedure may sound easy but there is typically little opportunity to schedule downtime to shut down production while these critical components are sent out for work. That process can take one or two weeks.

NPE stocks replacement bottles that can be matched to your system and swapped out in hours rather than weeks. Once we've provided identical replacements, we can evaluate the bottles that were taken out and either provide a credit for the "core" or we can recondition/repot them for replacement in other cells or to have on the shelf for spares for other GE circuit breakers.

Contact us online or give us a call at 216-898-2680 to discuss our Magne-Blast Bottle Repotting Program today.       

NPE specializes in having what you need when you need it.

Aftermarket parts are designed with modern materials and design enhancements: 

      Stronger materials

      Enhanced designs

      In stock and ready to ship

Extend the Life of Your Equipment with Replacement Aftermarket Parts

NPE’s aftermarket parts are available with improved designs and modern materials to help reduce failure rates and avoid downtime. Our experienced staff continuously works to identify solutions for hard-to-find and high-failure parts.

We use modern materials with an emphasis on strength and quality. Sometimes the changes can be as simple as a fiber-reinforced material or by filling voids to increase the strength of the part. Other times it could be a change in the concept of how the part performs. Why would you want to replace one poorly-designed part with another? NPE’s line of parts are made to fix the problem, not just put a band-aid on it.

In addition to our long and growing list of replacement parts for circuit breakers, we also stock an extensive and growing list of hardware and tools to help you safely move, lift, and maintain your circuit breakers and switchgear. Racking handles, extension rails, slow close, and spring removal tools are only a small sample of what we offer

Most often we find that our customers appreciate the prompt availability of our parts and our same day or next day shipping. All of our parts, especially the ones that have been out of manufacturing production for decades are in stock and ready to ship for delivery in hours or days, while OEM’s take weeks to ship even if they are in stock. Our products are available through your normal purchasing channels and in our online Aftermarket Parts Store. 

The Right Circuit Breaker Replacement Parts

As difficult as it is to correctly specify replacement circuit breakers, finding replacement parts can be much more challenging. Not only do you need to communicate all the correct breaker information, you also need all the information regarding the vintage changes of the internal parts as well. 

We specialize in fast, easy solutions for finding these parts. With a few questions and possibly a photo or two, our sales team will get you the right part at the right price and, if needed, right now!

Just email us at info@npeinc.com or use our mobile ap NPE on the Go!

Please take a moment to browse our available aftermarket parts store. If you don’t see what you need just let us know. If we don’t have an improved design or a used part, we would be happy to quote a new custom design just for you. In any case, you can be assured that we will do our best to find the best solution to solve your problem and get the power back on as fast as possible.

Contact us today to talk to one of our experts about aftermarket parts.

General Electric produced a line of medium voltage air circuit breakers called the MAGNE- BLAST for over 30 years. This product line was very popular and was produced in a wide range of sizes and ratings to meet customer’s needs.

Particular attention needs to be paid to several parts of the nameplate when you’re looking for replacement MAGNE-BLAST breakers or parts for these GE circuit breakers. This flow chart was designed to streamline the specification process and help you identify your MAGNE-BLAST designation.

Even with the flowchart, it can still be easy to miss specifics for designation There will be additional information that you will need. Rated Amps, close and trip voltage, and mechanism type can all be found on the nameplate. When in doubt, a photo of the nameplate and a photo of the breaker from the front will give your supplier a clear understanding of what you need. The following photos of MAGNE-BLAST nameplates show how important details like the letter suffixes are in determining exactly what you need.

Still confused? Contact us today or try our Mobile Ap- NPE on the Go  and we’ll help your figure it out. As a circuit breaker supplier, that’s what we’re here for.

Finding old or obsolete General Electric circuit breakers can be challenging. GE has produced circuit breakers for over 70 years, which can make it difficult to match the right models and model numbers to your needs. In this article, we’ll present a brief history of GE’s circuit breaker production and help you understand how to identify what circuit breaker you’re looking for.

A Brief History of General Electric Circuit Breakers

GE’s “Slate back” line of type AE and AL air circuit breakers was its first product line utilizing one of the first true inverse time elements to obtain automatic “resettable” overcurrent protection. These breaker lines have generally been upgraded since the original series overcurrent trip units with solid state trip units or retrofilled with more modern breakers  Sometime later, technological improvements prompted a redesign. GE iresponded by ntroducing the AK line of breakers. These models featured improved electro-mechanical trip units and were designed to fit both AKD and AKD5 switchgear.

In the 1980’s, GE redesigned the AK line and gave the product line the AKR prefix. Although they may initially seem similar in appearance to the older style, the AKR design has been improved and is not interchangeable with previous versions. This product line was designed to fit both AKD6 and the later redesigned for future vintages righ up through AKD10.

As products and technology continue to evolve through the Wavepro and AKD 10 up through and including Entelliguard and AKD 20 switchgear. These changes make it very important for users to be able to read breaker numbers to identify which type of breaker model they need.

How to Read a General Electric Breaker Number Basic Designation Chart

All of  the digits in an AK or AKR model number identify important characteristics of the breaker. It is important to either understand these details or be able to relay that information to a supplier that has a working understanding of them.

When it comes to reading and understanding an AK or AKR breaker number, let’s start by using an AK-25 circuit breaker as an example. At a glance, with the door closed, most AK-25’s look the same, but the missing digits between the AK and 25 reveal important information that is needed to assure a safe and proper fit. You can use these quick guidelines to identify the specific model of a General Electric circuit breaker:

4 Steps to Identifying GE Circuit Breaker Model with the 

1. The first part, “AK”, tells you the general designation of one of two switchgear vintages that the breaker will fit in - AKD or type AKD 5.
2. The last part, “50”, indicates one of the smaller feeder breakers that is rated 1600 amp AC continuous and has a frame rating of 50,000 amps interrupt (AC). 
3. There are up to 4 more spaces for letters or numbers between the AK and 25 that are important.
   1. One could be a “U” which would indicate the addition of current limiting fuses.
   2. Another could be an “F” which designates a special field discharge option.
   3. There will be a number, most likely a 2 but it could be a 3, 4, all the way up to 10, which designates which type of trip unit that was installed at the factory.
   4. After the 2 or other trip unit number there could be an “A”. Absence of an “A” indicates that it is for AKD switchgear, the presence of it indicates it is for type AKD5 switchgear.
4. For more information on how to understand what each letter or digit of the model number means, we’ve developed a guide. This guide will help you identify most of the options built into your breaker from the factory and which, if any, will need to be changed or upgraded.

Other Questions to Ask When Identifying Type AK and AKR GE Circuit Breakers

In addition to knowing the brand and product number you’re looking for, here are some other questions to help identify the perfect solution for your needs:

• Is the breaker A. electrically or B. manually operated?
• If A, what is the voltage of the close coil, control relay and trip coil?
• If A, do you have a wiring diagram number? 
• Why type of trip unit is needed?
• What trip function is required?
• Are any accessories like bell alarm or under voltage protection required?

To download this chart click here: flowchart for AK and AKR circuit breakers  If you’re still having trouble or are unsure of what you need, just let us know and we’ll be happy to walk you through the process.