MCC Identification: Production Years, Series Letters, Date Codes

MCC buckets fit their own product line only. Every replacement or addition therefore starts with identifying the lineup and its generation. The manufacturers publish more identification data than is commonly known: Eaton dates nine vintages of Westinghouse and Cutler-Hammer lines in its renewal-parts catalogs, Siemens publishes an identification guide with production years and serial formats for eleven models, and Rockwell dates every CENTERLINE 2100 design revision since 1971 by the series letter on the nameplate. That material is consolidated here.

1. Westinghouse / Cutler-Hammer / Eaton vintages, 1935 to present

Source: Eaton Cutler-Hammer, Motor Control Center Type F2100 Renewal Parts, RP04304001E, December 2002, pages 1 and 3-4. Eaton's own caveat applies: MCC types were sometimes produced outside the time spans shown due to production overlap when a new design was adopted. The same document dates 11-300 as 1935-1965 in one table and 1950-1965 in another. F2100, Advantage, Series 2100, and Five Star unit wrappers are mechanically identical per the same document.
Line	Production	Original manufacturer	Handle type	Original starter	Bucket width	Renewal parts pub.
F2100 (Freedom 2100)	1995 to present	Cutler-Hammer	Lever	Freedom + HMCP/HMCPE	13-3/4"	RP04304001E
Advantage	1992 onward	Westinghouse to 1994, then Cutler-Hammer	Lever	Advantage	13-3/4"	RP04304002E
Series 2100	1987-1995	Westinghouse to 1994, then Cutler-Hammer	Lever	A200	13-3/4"	RP04304003E
Five Star	1975-1987	Westinghouse	Lever	A200	13-3/4"	RP04304003E
Freedom Unitrol	1988-1994	Cutler-Hammer	Slider	Freedom	13-7/8"	RP04304004E
F10 Unitrol	1972-1989	Cutler-Hammer	Slider and lever	Citation	14"	RP04304005E
Type W	1965-1975	Westinghouse	Slider	A200 or 11-200	11-3/4"	RP04304006E
9800 Unitrol	1956-1974	Cutler-Hammer	Rotary (slider replacements)	Three Star / Citation	16-1/8"	RP04304007E
11-300	1935-1965	Westinghouse	Rotary	11-200 Lifeline / Type N / A200	15-3/4"	RP04304008E

Eaton's documented identification method when the nameplate is missing: handle mechanism type plus original starter type plus bucket width plus door width, matched against the table (RP04304001E, pages 3-4, with handle photographs per line). The corporate history behind the table: Eaton's Cutler-Hammer acquired Westinghouse's Distribution and Control Business Unit in 1994, which is why the mid-1990s rows change manufacturer mid-production. All nine vintages remain supported with renewal parts per the same document family, including Eaton guides for the Gould/ITE 5600 (RP04304010E) and the 11-300 (RP04304008E).

2. Siemens family: Allis-Chalmers, Furnas, ITE/Gould heritage

Source: Siemens MCC Identification Guide, order no. CCBR-MCCAR-0813, 2013. Siemens captions its timeline chart as approximate values. Heritage per the same guide: Siemens acquired Allis-Chalmers 1978, ITE Gould 1983, Furnas Electric 1996. tiastar is based on the Furnas System 89 design and splices directly to System 89, 95, 95+, 90, and Marq21 lineups.
Model	Production	Original manufacturer	Handle	Serial / style format
tiastar	2002 to current	Siemens	Lever	89BF#####-###, 89BS, 89BB
Model 95+	1997-2001	Siemens	Slider	95BF/95BS/95BB#####-###, W####
Model 95	1995-1997	Siemens	Slider	09-001-####-#####-###
Model 90	1990-1997	Siemens	Slider	30-001-####-#####
Marq21	1975-1990	Siemens-Allis	Slider	01-14##-#####-##
System 89	1980-2001	Furnas Electric	Lever	89-prefix formats, as tiastar
Class 89	1965-1979	Furnas Electric	Lever	89FV/89SV/89BV##-###
Mark 2	1972-1975	Allis-Chalmers	Rotary	numeric
Mark 1	1965-1972	Allis-Chalmers	Slider	numeric
Gould 5600	1971-1992	ITE / Rowan Control	Rotary	84-/85-/86-#####
Gould 9600	1964-1971	ITE / Rowan Control	Rotary	84-/85-/86-#####

Identification per the Siemens guide: the style number on the nameplate, generally located on the incoming power section, identifies the line by its prefix. Two support facts from the same document: Class 89, Mark 1, and Gould 9600 replacement units are no longer available (cabled tiastar add-ons only); and Marq21 sections built 1982-1985 may carry a vertical bus phase-isolation barrier that blocks Model 95 style retrofit buckets, requiring panel-mounted cabled units instead.

3. Allen-Bradley CENTERLINE 2100: dating by series letter

Every CENTERLINE 2100 vertical section carries a nameplate on the vertical wireway door with a series letter. Rockwell publishes the date each letter entered production, which makes the nameplate a date code:

Source: Rockwell Automation publication 2100-IN012M-EN-P, April 2024, Table 2, series numbers as manufactured in the United States. Unit series letters run A (Feb 1971) through Z (Jan 2018, Bulletin 1494U disconnects) in Table 3 of the same publication. Rockwell states renewal parts are no longer supported for section series A through G, and sections series A or B cannot take modern unit additions without engineering review.
Section series	Entered production	Design change
A	Feb 1971	Original design
B	Nov 1976	Changed terminal blocks
C	Jun 1979	Eliminated external mounting channels
D	Apr 1981	Reverse-fed 2192/2193 units
E	Oct 1982	Gasketing redesign
F	Jan 1985	42 kA bus bracing, new bus support and cover
G	Jul 1985	65 kA bus bracing
H	Jan 1986	New hinge design
J	Oct 1986	Cutler-Hammer Series C breakers and operating mechanisms, 150/250/400 A
K	May 1990	New unit grounding system
L	Feb 1996	New 600-1200 A breaker operating mechanism
M	May 2001	Serpentine DeviceNet cabling
N	May 2009	100 kA bus bracing
P	Feb 2012	New bus cover design

4. Square D: documented anchors

Schneider publishes no launch-year table for Models 3-6; the rows above are the documented anchors. Model 6 identification features per 8998CT9701: cast metal disconnect handle indicating tripped status, shrouded self-aligning power stabs, vertical ground bus mating with unit ground stabs (first-make, last-break), quarter-turn fasteners on unit and wireway doors.
Model	Documented fact	Source
Model 6	Current production line. First catalog is 8998CT9701 (catalog number dates it January 1997), copyright 1997-2009.	Schneider catalog 8998CT9701R07/09
Model 5	Structural design change May 1992: Model 6 splices directly to Model 5 structures built after May 1992; earlier structures require custom splice plates.	Schneider catalog 8998CT9701R07/09, transition section pages
Model 5	Handles, linkages, and saddle assemblies obsolete.	Schneider FAQs FA127402, FAQ000269132
Model 4	Structures no longer available as of 2009; transition sections match existing Model 4 to Model 6. Depth compatibility: Model 6 15" deep splices to 14" deep Model 4.	Schneider Supplemental Digest 12, Obsolete Motor Control Centers, 2009
Series 5600 (supported by Schneider)	Sold from 1970 under ITE Circuit Breaker/ITE Imperial; ITE Imperial merged with Gould 1976; Gould industrial controls sold to Telemecanique 1985; Telemecanique acquired by Groupe Schneider 1988; Square D acquired 1991. Production ran more than 20 years. Model 6 transition sections available.	Schneider Supplemental Digest 12

5. GE / ABB

No manufacturer-published year table exists for the 7700 to 8000 transition. Renewal parts literature: GEH-4961 (8000 line installation and maintenance), GEF-4629 (7700 line renewal parts).
Fact	Source
ABB acquired GE Industrial Solutions in 2018; the 8000 line is serviced and maintained by ABB.	ABB GET-6728, March 2025
The 7700 line, 8000 line, and Spectra Series are no longer manufactured as new lineups. ABB supports them with new buckets and spare parts from Mebane, NC.	ABB GET-6728
2700, 7700, 8000, and Spectra Series buckets, cabinets, and vertical buses are compatible; 2700/7700/Spectra are supported with 8000-style buckets.	ABB GET-6728
Nameplate is on the vertical wireway door of each section. ABB identifies sections from a nameplate photograph against original factory drawings.	ABB GET-6728
Stab identification cue: wedge-shaped silver-plated copper unit power stabs under double spring pressure; vertically mounted integral unit handle lockable with three padlocks.	ABB GET-6728

6. Date codes on components

Manufacturer	System	Source
Square D	Modern: 4-5 digit code, first two digits year, next two week (0235 = week 35 of 2002); fifth digit day-of-week since Aug 2016. Legacy: two-letter code, first letter month, second letter year, year letters repeating on an approximately 21-year cycle.	Schneider data bulletin 0110PD9201, Date Code System
Allen-Bradley	No numeric date code; date via the series letter tables above, or catalog/serial number to Rockwell LV MCC support.	Rockwell 2100-IN012M-EN-P
Eaton / Cutler-Hammer / Westinghouse	No numeric date code published for MCC nameplates; vintage placed by the handle and dimension matrix in section 1.	Eaton RP04304001E
Siemens family	Style number prefix on the incoming-section nameplate identifies the line and era per the table in section 2.	Siemens CCBR-MCCAR-0813

Sources

1. Eaton Cutler-Hammer, Motor Control Center Type F2100 Renewal Parts, RP04304001E, Dec 2002. Companion vintage guides RP04304002E through RP04304008E and RP04304010E (Type 5600).
2. Siemens Industry, MCC Identification Guide, CCBR-MCCAR-0813, 2013.
3. Rockwell Automation, CENTERLINE 2100 Installation Instructions, 2100-IN012M-EN-P, April 2024, Tables 2-4.
4. Schneider Electric, Model 6 Motor Control Centers catalog, 8998CT9701R07/09.
5. Schneider Electric, Supplemental Digest 12, Obsolete Motor Control Centers, 2009.
6. Schneider Electric, Date Code System data bulletin, 0110PD9201.
7. ABB, Spectra Series and 8000-Line Motor Control Centers Application and Selection Guide, GET-6728, March 2025.