Replacing Bottles in GE Magneblast Switchgear

The General Electric Magneblast is one of those iconic circuit breakers that if you spend any time in or around switchgear, you will have reason to deal with them. Manufactured from the 1950's through the early 1970's, they are usually found in large manufacturing facilities, from automotive plants to steel mills to repurposed properties that once had high volume production runs of one kind or another. It is sometimes called a "vertical lift" breaker. It is characterized by a unit that rolls into an enclosure and then lifted vertically into place and then connected to the line and load side by means of a vertical lift mechanism.

With ratings from 2.4kV through 15kV, frame sizes of 600, 1200, 2000 and even 3000 amp and interrupting ratings from 50MVA to 1000MVA, these breakers cover almost every conceivable industrial, commercial and utility application. Documentation for most of these frames can be found on our website www.npeinc.com/resources  or by contacting NPE personnel with specific requests at info@npeinc.com, 800-647-0815 or by fax 216-898-2684, yes, we still have one!

We have found over time, the original "tar pitch" that was used to insulate the primary conductor in the center of the primary disconnect bottle has outlived its useful lifespan. It can crack and absorb moisture and loosen the connection inside and eventually lead to catastrophic failure. That's where NPE and our experience can help to increase the safe, useful lifespan of your switchgear with our repotting program.

Regardless of what your GE Magneblast breaker and switchgear needs are, you will find that NPE has "The right part, at the right price, right now!"

National Power Equipment, Inc. is your one stop shop for air and vacuum circuit breakers, switchgear, primary switches, motor starters and of course, parts!

Allis Chalmers/Siemens Allis Cell Bottles...Almost Everything You Wanted to Know, but Didn't Know to Ask!

The cell bottles (primary disconnects) in Allis Chalmers horizontal drawout switchgear can be a little tricky to replace. These bottles are typically found in cabinets designed to operate FC, FB, FCV, FSV - 500 MVA - 1000 MVA circuit breakers. For example, FC-500, FB-500, FSV-500, FCV-750, etc. This follows all assembles rated 1200 amp or 2000 amp.

The assembly consists of a porcelain "bottle" with a round conductor on the inside which terminates in a flat conductor on the outside. The entire assembly is sealed on the outside with a molded insulation. The assembly is held in place with a steel mounting ring.

Of the six bottles in the cell, there are three different sizes. Three different ones on the line side so that the buss staggers to meet the cross buss and three of the same size on the load side. The tallest of the three measures roughly 16". The medium size measures around 12", and the shortest size measures approximately 9" from the base to the top of the conductor on the bottle.

Short                                                     Medium                                                         Tall

When these assemblies need to be replaced this information will need to be conveyed to our salesman to enable him to ensure that you will receive the correct assemblies. 

So give us a call or send us an email with as much information as you can and we'll take it from there!

NPE where our motto is "The right part, at the right price, right now!" 

General Electric produced tens of thousands of Magne-Blast breakers in various sizes from the early 1950s through the 1970s.

Continued maintenance of the original air breakers or upgrading them with a vacuum retrofit has helped to extend the lifespan of this product line but there are other critical components in the switchgear that also need maintence and upgrading to maintain safety and overall reliability.  Today we are  going to address one of those components, the "Primary Disconect" more commonly known as the "Cell Bottles". This critical component consistes of three porcelain mounted on an aluminum base with copper conductors rising from the top in various configurations to meet the line or load side connections in the switchgear. 

Why Magne-Blast Bottles Need to be Repotted

The element that we are addressing here is the old style "tar pitch" that was used to stabalize the riser buss and fill the void between the conductor and the bottle. This pitch ages and cracks over time with will not only allow dirt and moisture to enter the cracks but also tends to allow the spring loaded tulip inside to bottle to wiggle and misalign with the breaker and can be the source of more catastrophic failures or just a loose high resistance connection. 

 This illustration shows a typical set of bottles with one phase on the left "before" the middle phase "during" and the right hand phase after the upgrade is complete. 

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, reach out to National Power Equipment Inc. One of our specialties is repairing, upgrading and supplying replacement bottles that are upgraded with our proprietary 2 part epoxy for a true one and done solution. 

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 base filler.     
3. 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. Remove the olde buss insulation and 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. Perform final tests in a shop fixture to ensure proper alignment and overall performance. 

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 which can take several 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 return to inventory for future needs. 

Either way it demonstrates our commitment to "The right part, at the right time, right now!"

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