Blog posts tagged with 'westinghouse breakers'

Westinghouse DA Circuit Breaker Line

George Westinghouse was one of the primary innovators of the Industrial Revolution and of the electrical power distribution and control industry that developed along with it. His company continued to spearhead innovations created by inventors such as Edison, Tesla and others which included polyphaser motors and the first resettable circuit breakers made with interchangeable parts. This product line is commonly known in the industry as Westinghouse slatebacks or the DA series of breakers. They both used thermal and inverse time overcurrent trip devices that sensed an overload condition and safely tripped to open the circuit to prevent damage to infrastructure, equipment as well as injury to personnel. Once the circuit was safely de-energized, technicians could locate and clear the cause of the fault and re-energize the circuit with minimal efforts.

 

This product line consisted of a robust current path mounted on a heavy slateback board and integrated into both live front and later dead front (enclosed) switchgear sections. Although this product line was advertised to have interchangeable units and parts, there was a wide variety of products to choose from and variables could only be identified by technicians familiar with the equipment, including changes caused by products marketed by a budding OEM of the time. In order to weed through these issues I will begin with the basics and fine tune the details as we go. Of course, if you need one of these quickly and don’t want to get bogged down in the weeds, just contact one of our experts at 800-647-0815 or use NPE’s “On the Go” tool - M.NPEINC.COM.

 

The basic product line came in 5 different designations, defined by how many amps each could be relied on to interrupt safely, based on standards in place at the time. These are DK 15, DK 25, DA 50, DA 75 and DA 100. Each of these breakers could be provided in either a drawout or bolt-in frame. These breakers were built to last and it’s not unusual to see them still in service today with upgraded electronic trip units. The bolt-in breakers are the toughest to identify and replace because they have often been incorporated into large control panels with various other controls. Things like size and placement of the bus, vertical or horizontal bus alignment and number of phases along with field discharge legs are a few of the criteria which must be identified and are best done with photographs and sketches along with the technical details.

 

The drawout breakers, while they still needed to be carefully examined, are much easier to identify and replace. The vast majority of them (say 98%) worked with a standard design that George Westinghouse was proud to put his trademark on. More on the other 2% later…

 

Westinghouse Drawout “DA” Style Slateback Breaker Types and Sizes:

 

MODEL

INTERRUPTING RATING

FRAME SIZE CONTINUOUS

 

COMMENTS

DK 15

15,000 amps

225 amps

 

Finger cluster style does not affect interchangeability as long as they are for round bus**.

DK 25

25,000 amps

600 amps

 

Finger cluster style does not affect interchangeability as long as they are for round bus**.

DA 50

50,000 amps

800, 1200 and 1600 amps

 

Frame size is not indicated by the nameplate on the front of the breaker. The breaker nameplate indicates the rating of the trip unit as supplied from the factory. Frame size, can be best be identified by the size of the round copper stab that the finger clusters are mounted on 7/8” for 800, 1 ¼” for 1200 and 1 5/8” for 1600 amp. Electrically operated breakers are in no way interchangeable with manually operated breakers. The 800, 1200 and 1600 amp frames are not interchangeable.

DA 75

75,000 amps

2000, 2500 and 3000 amps

 

Finger cluster style does not affect interchangeability as long as they are for round bus**. Frame size is not indicated by the nameplate on the front of the breaker. The nameplate only indicates the rating of the trip unit as supplied by the factory. Frame width varies between two sizes and finger cluster/back stab arrangement can also vary between 6 stab and 12 stab versions on a “standard” three phase breaker. The only reliable way to identify the breaker is with a measurement of the width and to photograph or otherwise visually inspect the back of the breaker.

DA 100

100,000 amps

various 4000-12,000 amps

 

Frame width varies and finger cluster/back stab arrangement can also vary between 6 stab and 12 stab versions on a “standard” three phase breaker. The only reliable way to identify the breaker is with a measurement of the width and to photograph or otherwise visually inspect the back of the breaker. This is a very rare breaker in today’s world. Engineers of the day theorized that anything above a 100,000 amp fault was impossible and used the base DA 100 design with a variety of ever increasing frame sizes. 4000 amp is the most common. Use all of the above guidelines to identify your application.

 

 

 

 

 

 

 

 

 

**The Other 2 Percent:

 

The above guidelines will help you identify the correct replacement for your Westinghouse slateback breaker 98% of the time. However, “back in the day”, Westinghouse also sold its stationary breakers to Allis Chalmers for use in its own OEM version of switchgear. Allis Chalmers would take stationary breakers, with flat stab (and all of the variables associated with them) and add their own finger clusters and drawout hardware. This resulted in a drawout circuit breaker with finger clusters designed to mount on flat bus rather than the standard Westinghouse round stab as noted above. To complicate matters, the Westinghouse factory nameplates remained on the breakers and no outward indication was given that they have been modified by an OEM and not interchange with standard factory breakers.

 

In conclusion,please keep in mind that equipment of this era was made during a period of time when the idea of standards for interchangeable parts left some room for interpretation. It will take a supplier with experience and an eye for detail to ensure that the your equipment fits and functions the way that George Westinghouse’s company intended, like the professionals at NPE. We’re breaker geeks -this is what we do. Give us a call, send us an email or use NPE’s “On the Go” tool and have it guide you through all of the steps you will need to find the right breaker for your job.

                                               

 

 

 

 

 

   

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.