How to Identify Raise Lower Mechanisms for Circuit Breakers and What You Need to Maintain Them

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.

Image of a cast raise lowe mechanism for a GE Magne-Blast circuit breaker.Image of a fabricated raise lowe mechanism for a GE Magne-Blast circuit breaker.

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!

Extend the Life and Reliability of Your GE Magne-Blast Switchgear with NPE’s Bottle Repotting Program

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.

 

  1.      Remove the outdated “tar pitch” potting right down to the filler. 

  1.      Re-align the connecting tulip and lock it in place so it doesn’t move and cause future failures.

 

  1.      Secure the joint between the copper and seal.

 

  1.      Insulate the buss with modern shrink tube insulation.

 

  1.      Replace the old potting material with a new two-part system that is thermally stable which will last far into the future.

 

  1.      Clean and silver plate all mating surfaces to increase conductivity at critical joints.

 

  1.      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 typically 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.

Reduce Failure Rates and Avoid Downtime with NPE’s Circuit Breaker Aftermarket Parts

It is well known in the industry that National Power Equipment has thousands of available reconditioned parts, assemblies and subassemblies. NPE has now taken the business of supplying parts to a new level by introducing a product line of aftermarket parts for industrial circuit breakers and switchgear.

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!

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.

Finding Electroswitch Lock-out Relays – Series 24 and 31

Lock-out relays provide reliable protection of critical utility equipment. Electroswitch lockout relays can accommodate nearly any lock-out switching application in the electric power industry and can be the difference between a routine outage and the destruction of expensive equipment.

Finding these high-quality Electroswitch lock-out relays can be challenging. Even browsing switchgear providers’ catalogs and websites, or other Electroswitch distributors, can yield low or no inventory. However, National Power Equipment regularly stocks these lockout relays, including the popular Electroswitch Series 24 lock-out relays and Electroswitch Series 31 lock-out relays.

Electroswitch Series 24

This series features low resistance, double-wiping contacts with self-cleaning silver contacts for long-term reliability. They come available with up to 10 decks (20 poles) and allow for between two and eight positions. Series 24 switches are rated at 30 amps @ 600 volts.

These lock-out relays have been put to the test over the years in heavy duty applications, including military and power switching applications.

Features include:

  • Double-sided, Double-wiping, Knife-type rotary contacts
  • Silver Contact Surfaces
  • #8-32 Terminal Screws
  • Standard Three-Hole Panel Mount

Reading Electroswitch Series 24 Product Numbers

Identifying the exact part number you’re looking for can be difficult. Here are some tips on finding the exact Electroswitch part number you’re looking for:

  • To better understand the lettering in the product number, use this guide:
    • A=Single LED, Amber, 48/125VDC
    • B = Two LEDs, Green/Red, 48/125VDC

    • C = Three LEDs, Green/Amber/Red, 48/125VDC

    • D = Three LEDs, Green/Red/Red, 48/125VDC (Dual Trip Coil Monitor)

    • E = Single LED, Amber, 120VAC

    • F = Two LEDs, Green/Red, 120VAC

    • G = Three LEDs, Green/Amber/Red, 120VAC

  • Example: A breaker control switch with a pistol grip handle (PG), Lighted Target Nameplate, three LED’s, and 120VAC LED voltage would be part number 24PG38D

View all available Electroswitch Series 24 Relays available from National Power Equipment

Electroswitch Series 31

This series features low-resistance, double-wiping contacts in a smaller package. They are available with up to 10 decks (20 poles) and allow for between 2 and 8 positions. Series 31 switches are rated at 15 amps @ 600 volts.

Features include:

  • Double-sided, Double-wiping, Knife-type rotary contacts
  • Silver Contact Surfaces
  • Terminal Screws
  • Standard Four-Hole Mount

Reading Electroswitch Series 31 Product Numbers

Use the graphic below, sourced from Electroswitch’s “Switches and Relays for the Power Industry” Guide, to identify the exact product number that you’re looking for:

Image to help identify product numbers for Electroswitch eries 31 lock-out relays.

View all available Electroswitch Series 31 Relays available from National Power Equipment

About Electroswitch

Electroswitch Corporation is a leading manufacturer of electronic switches, relays, and photocontrols. The company was founded in 1946, and over the years began designing and building high-quality switches for the heavy duty Industrial and Electrical Utility markets. Through a series of acquisitions in 1908, Electroswitch became the industry leader in electrically-operated auxiliary relays, and their products are used in virtually every major electric utility in the United States and Canada.

If you’re looking for a specific Electroswitch lock-out relay but can’t find it in our catalog, contact us or give us a call at 216-898-2680.

 

 

Identifying MAGNE-BLAST Circuit Breaker Designations

General Electric produced a line of medium voltage air circuit breakers called the MAGNE- BLAST for over 30 years. The 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.

Image of a designation flowchart for MAGNE-BLAST circuit breakers.

Even with the flowchart, it can still be easy to miss specifics for designation There will be additional information you will need. Rated Amps, close and trip voltage, and mech 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.

First nameplate image from a MAGNE-BLAST circuit breaker.
Second nameplate image from a MAGNE-BLAST circuit breaker.

Still confused? Contact us today with what information you have and we’ll help your figure it out. As a circuit breaker supplier, that’s what we’re here for.