Load Bread Switches – A History by Manufacturer

Westinghouse and Cutler-Hammer WLI Load Break Switches

Westinghouse began manufacturing load break switches in 1950, with 5KV-15KV being the most popular sizes. The earliest switches were non-load break types, and were called Westinghouse LBF switches, while the next generation of switches were dubbed WLI load interrupters. Also made by Cutler-Hammer, WLI type load break switches were manufactured through 1980. Cutler-Hammer currently makes the MVS load break switch, available in 5KV-15KV and 38KV.

ITE HPLC and ABB Load Break Switches

ITE started making load break switches right after WWII, again with the most popular sizes being 5KV and 15KV. The ITE models were called the HPLC Load Break Switch and thery came in both fused and non-fused varieties and were produced for over 30 years. ITE was sold to Gould and then Brown Boveri before ultimately resting under the ABB moniker, and continued to market the HPLC load break switch throughout. ABB produced their own load break switch called the ABB Versa Switch, that came in the standard 5KV, 15KV and 38KV ratings and were available for a very limited time from 1970-1980.

General Electric Load Break Switches

As General Electric by far built the most switchgear in the United States from 1945 – 2000, GE load break switches were the most popular models. And the best-selling model was called the SE-100S Load Break Switch. The switch had a stored energy (SE) design and came in many different configurations including NEMA 1 Indoor and NEMA 3R outdoor and fused or non-fused. As a cost-efficient way to get complete plant distribution, General Electric often made large switchgear lineups with their load break switches as they generally cost less than their smarter brother the circuit breaker.

Where and Why to Buy Load Break Switches and Parts

Circuit Breakers Sales Northeast offer a huge inventory of every generation of medium voltage switches. More important, we stock thousands of standard and hard-to-find parts for load break switches, the most common of which are the right 5KV and 15KV fuses needed both for replacement and spares, often found sitting in a “pocket” in the front door of the switch.

Interestingly, load break switches from different manufacturers always need different parts, as diverse designs produced diverse weak points. For example, on the GE SE-100S load break switch, the “whipper blades” will fail as a small contact on the blade often breaks off as the blades whips into the arc chute. Westinghouse and Cutler-Hammer WLI switches seem to always require mechanism parts, as the torque put on the mech during closing tends to break key parts. ITE HPLC load break switches constantly require handle assemblies or porcelain push rods that frequently break, just as the ABB Versa Switch also had problems with their glastic push rods.

Circuit Breaker Sales Northeast are a consortium of switchgear and circuit breaker experts with decades of knowledge and experience gained from working closely with the manufacturers themselves, We are well-versed in dealing with Westinghouse, Allis Chalmers, Siemens Allis, Federal Pacific/Federal Pioneer, General Electric, ITE/ABB and Cutler Hammer and others. We understand functions, types, components, voltage ratings, ampere ratings, ampere interrupting capacity, testing, electrical arc, effects of current flow, thermal energy, magnetic trip elements and every other detail behind the proper functioning of all your circuit breakers and associated electrical equipment. Combine that expertise with nearly 200,000 square feet of inventory, shop and test space, and we are the one-stop source for all your load break switch needs.

Circuit Breaker Inventory – Bigger is Better -> GE

Used Circuit Breakers -> GE

Circuit Breakers and Switchgear from 1945

Prior to 1945 facilities had large fuses. The first air circuit breaker was made during the war effort in 1945 and was the first re-settable fuse.

GE AL-2-50 breakers, ITE KC circuit breakers, Westinghouse DA-50 circuit breakers – which were 1600 Amp frame sizes, were part of an original switchgear family of breakers which featured air breakers from 600 Amp frame size to 4000 Amp frame size.

The big breakers were mounted on slate back frames and had oil dashpot trip units. These oil dashpot trip units, while revolutionary at the time, had problems with the oil leaking out of the trip unit or getting too heavy.

Circuit Breaker Sales NE., carries all the original breakers from this era, by ITE circuit breakers, FEDERAL PACIFIC circuit breakers, WESTINGHOUSE circuit breakers and ALLIS CHALMERS circuit breakers.

These early companies paved the way for the power generation industry for years to come.

Ground and Test Devices 5KV-7.5KV or 15KV -> Switchgear

Westinghouse Air Circuit Breakers 600V: 1945 – The Present

In 1955 circuit breakers became smaller and faster. GE introduced the AK line of circuit breakers. The GE AK circuit breakers were smaller, lighter, and more reliable than their earlier GE AL counterparts. These models featured electro-mechanical trip units and plastic pole bases. The changes allowed for more reconditioned circuit breakers and remanufactured circuit breakers. GE continued to make the AK circuit breaker for the next 30 years. These models included: 600 amp GE breakers AK-1-25, AK-2-25, AK-2A-25, AK-3A-35, AK-4A-25, AK-5A-25, AK-6A-25. 1600 amp circuit breakers manufactured over the same time period were: AK-1-50, AK-2-50, AK-2A-50, AK-2A-50S high-speed circuit breaker, AK-3A-50, AK-4A-50, AK-5A-50 and the AK-6A-50. At this time GE also introduced a 2000 amp frame size, the GE AKT-2-50. In 3000 amp sizes selection there was the GE AK-1-75, AK-2-75, AK-2A-75, AK-3A-75 AK-4A-75, and AK-5A-75. The largest circuit breakers made during this time period (1955-1986) were the GE AK-1-100, AK-2-100, AK-2A-100, AK-3A-100 and AK-4A-100.

Around 1985 GE introduced the AKR line of circuit breakers, after decades of rebuilt circuit breakers. This was a major design change, and led to the GE AKR circuit breakers being able to communicate information back to a central pc. There were several variations on the AKR line of circuit breakers, mostly upgrades the solid state trip units and changing the racking mechanisms. The model numbers for these types are as follows.GE AKR-5A-30, AKR-5B-30, AKR-6D-30, AKR-7D-30, AKR-8D-30, AKR-9D-30, AKR-10D-30.

Fused models were the GE AKRU circuit breakers, and high interrupting models were always signified with an ‘H’ at the end of the serial number (such as AKR-7D-30H). 1600 amp frame sizes were the next size. 1600 amp AKR air circuit breakers are known for serial numbers that begin with “AKR’, some model types you might find are as follows: AKR-5A-50, AKR-5B-50, AKR-5D-50, AKR-6D-50,AKR-7D-50, AKR-8D-50,AKR-9D-50, AKR-10D-50. Around this time popular models included the fused 1600 amp air circuit breakers AKRU-6D-50 and H model high interrupting circuit breakers. Low voltage power circuit breakers in the 3000 amp frame size were GE AKR-5A-75, AKR-5C-75, AKR-5B-75, AKR-6D-75, AKR-7D-75, AKR-8D-75, AKR-9D-75. 4000 amp frame size circuit breakers followed a similar pattern, GE AKR-5A-100, AKR-5B-100, AKR-6D-100, AKR-7D-100, AKR-7F-100.

The GE AKR low voltage air circuit breaker line was very popular and reliable. The current GE line of GE circuit breakers are called the GE Wavepro Series, these circuit breakers have introduced a completely new technology to switchgear.

Circuit Breaker Sales NE has a complete line of GE from past to present, along with an extensive parts inventory if your unit may only need a small piece replaced. Contact us at any time for a quote, consultation, or a visit to your facility for an assessment!

Motors for Westinghouse DHP 5KV and 15KV Medium Voltage Circuit Breakers

Westinghouse DHP circuit breakers came with several different motor designs. The earlier Westinghouse DHP breakers, whether they are for 5KV DHP or 15KV DHP breakers, were solenoid operated. They had a big closing coil, like most early medium voltage breakers built in the early 1960’s.

Circuit breakers in the late 60’s became motor operate-spring loaded. This provided faster closing Times for the DHP or porcelain design breakers.

The earlier breakers featured a cast mechanism and the motor ran horizontally in the middle of the mechanism. It was hard to get to from a maintenance point of view.

The later Westinghouse DHP circuit breakers had a wielded design and the motor was put in a much more convenient spot for maintenance. The motor ran front to back, and was located near the rear of the wielded mechanism, making it much easier to be removed for service.

When inquiring to purchase a motor for your spring loaded DHP circuit breakers, it is important to specify closing voltage (motor voltage) and which design you have – vertical or horizontal.

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