History and types – GE Industrial Solutions EntelliGuard R AKD-8 User Manual
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EntelliGuard R Circuit Breaker Retrofill AKD-8 Installation Manual DEH-41549 02/12
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General Electric AKD-8 Low Voltage Switchgear is a free-standing assembly of metal-enclosed units of power
circuit breakers and other auxiliary power circuit protective devices. It may also be a part of a single-ended
or double-ended load center unit substation. It’s defined as a draw-out breaker.
Figure 1
(front and back
views with finger clusters) presents an AKD-8 EntelliGuard R Retrofill breaker, permanently encased in a
cassette-like structure.
Figure 1. AKD-8—AKR30H\50H Breaker in Cassette (Front View)
The EntelliGuard R Circuit Breaker is suitable for application on power systems up to 635 VAC 50/60 Hz
systems and up to 1000 Vdc as a main/source breaker, feeder breaker, bus coupler, or tie breaker.
History and Types
AKD
AK — Power Circuit Breaker Equipment
D — Drawout circuit breaker construction
Manufactured from 1951 to 1975, the breakers had these characteristics:
• All bolted
• Copper bus design
• All drawout-breakers—AK-1, —2, —3,—15 / 25 / 50 / 75 / 100
• 4000A-max bus rating
• 4 levels of bus
• Ring-bus used in all feeder sections
• Main bus with provisions for future extension
• Sections in outdoor construction, which did not line up in the front
• Indoor construction, with extended frames, allowing the section fronts to line up
• Indoor depths of 49" (225 / 600A breakers)
• Indoor depths of 59" (1600A breakers)
• Indoor depths of 63" (3200 / 4000A breakers)
Back then, breakers had a ratcheting drawout mechanism, with an open-door drawout. Breakers were
painted ANSI 61, light gray, manufactured in Philadelphia from 1951 to the mid-60s and in Burlington from
the mid-60s to 1975.
The breaker compartment was a welded assembly, and the equipment frame was bolted. Breaker boxes
were stacked to make a vertical section with equipment frame around the breaker boxes. There were no bus
compartment barriers, just an open bus design. Ring silver-plating was applied to bolted connections.