Square D Model 6

Class 8998, in production since 1997 and still current. Everything below comes from Schneider catalogs, instruction bulletins, and Digest sections, cited under each table, plus what we know from building Model 6 buckets every day.

Square DUpdated August 10, 2026

Where Model 6 sits in the Square D line

Model 6 is the fourth and longest-lived generation of Square D motor control centers. It replaced Model 5 in 1997 and has outlasted every competitor generation of its era; a lineup installed in 1998 accepts a unit built to today's catalog. That 29-year run is why Model 6 is the most common MCC in American plants, and why the aftermarket for its buckets is the busiest in the industry. We stock hundreds of Model 6 units and build to order daily in our UL 508A shop.

Scroll horizontally to view all dates.

Solid spans and marked dates are documented in Schneider literature (catalog 8998CT9701, Supplemental Digest 12). Faded bar ends are approximate: Schneider publishes no launch-year table for these models, so predecessor spans reflect industry consensus, not catalog dates.

1. Identification: is it a Model 6?

Sources: Schneider catalog 8998CT9701 (construction features); Schneider FAQs FA127402 and FAQ000269132 (Model 5 handle obsolescence); Schneider data bulletin 0110PD9201 (date code system).
Check	Model 6	Distinguish from
Disconnect handle	Cast metal handle that indicates ON, OFF, and TRIPPED breaker status	Model 5 handles are obsolete-style with different linkage; Schneider lists Model 5 handles and linkages as no longer available
Unit fasteners	Quarter-turn fasteners on unit and wireway doors	Model 4 and older use captive screws
Power stabs	Shrouded, self-aligning stabs; vertical ground bus engages a unit ground stab first-make, last-break	Earlier models lack the shrouded stab and ground-stab arrangement
Structure nameplate	States the model designation	Nameplate location and content varies on older lines
Date code	Modern Square D code: first two digits year, next two week (0235 = week 35 of 2002)	Legacy two-letter codes on oldest components repeat on a 21-year cycle

One splice fact matters when extending lineups: Model 6 splices directly to Model 5 structures built after May 1992; earlier Model 5 structures require custom splice plates. Schneider also builds transition sections matching Model 6 to Model 4 (15" to 14" depths) and to the Telemecanique/ITE Series 5600 (catalog 8998CT9701 transition pages; Supplemental Digest 12).

2. Structure specifications

Sources: Schneider catalog 8998CT9701 pp. 7-15; instruction bulletin 80459-641-01 Rev 12 (02/2026), About and Space Requirements sections; quick start guide 80459-641-04 Rev 02 (10/2025).
Item	Specification
Section size	90" H x 20" W standard (91.5" with base channel; add 3" removable lifting angle); 25" W option with 9" wireway
Depths	15" or 20" front-of-board; 31" or 41" back-to-back
Unit space	72" of vertical unit mounting space per section; reduced-height structures give 60"/54"/48"
Unit increments	6" minimum unit height; vertical bus stab openings every 3", each with a manual shutter
Vertical wireway	4" wide, full depth (9" in 25" sections)
Enclosures	NEMA Type 1, Type 1 gasketed (1A), Type 12, Type 3R; Type 1 sprinkler-resistant variant with its own gasketing and pull box
Pull boxes	Top pull boxes add up to 18"; standard 18" pull box on ArcBlok 1200 top-entry mains; vented and sprinkler-resistant versions
Frame	12-gauge steel with welded corner channels
Clearances	3 ft working space in front (plus 3 ft rear for back-to-back); minimum 0.5" wall gap, 6" in damp locations

3. Bus system

Sources: Schneider Digest section 17 (current ratings); 8998CT9701 pp. 13-14; 80459-641-01 Rev 12 torque tables. Bus ampacity per UL 845 is rated at 65 C maximum rise over 40 C ambient; sections and units are listed independently, so a listed section can legally contain non-listed units (8998CT9701 pp. 9, 13).
Bus	Ratings	Notes
Horizontal (main)	600 / 800 / 1200 / 1600 / 2000 / 2500 / 3000 / 3200 A	Tin-plated aluminum available 600-1200 A; tin- or silver-plated copper all ratings; 1600 A and up require 20" depth. The 3000/3200 A tier was added after the 2009 catalog.
Vertical	300 A standard; 600 A and 1200 A options	Tin- or silver-plated copper; 1200 A tier is the current Digest listing
Ground	Horizontal 300 A standard, 600 A option; vertical ground bus steel standard, copper option	First-make, last-break engagement with unit ground stabs
Bracing	42 kA standard; 65 / 85 / 100 kA options	100 kA at 480 V maximum; 85 kA tier added after 2009
Splice torque	600-2500 A splices: 31-32 lb-ft; 3000/3200 A: 70 lb-ft	Single bar/phase splice kit applies to 600/800 A copper bus at 65 kA or less shipped after August 2012; 1600 A splices have a dedicated bulletin, 80459-656-01

4. Units: types, heights, and the plug-in limit

Two families exist: standard units and the 6" Compac 6 high-density units. Everything through the 400 A breaker frame plugs onto the vertical bus; larger disconnects cable directly to the horizontal bus, and only one disconnect 400 A or larger is permitted per section.

Source: 8998CT9701 p. 36. Reversing starters run taller: Size 1-2 at 18", Size 3 at 27", Size 4 at 33", Size 5 a full 72" section 25" wide (p. 39).
NEMA starter size (FVNR, breaker type)	Unit height
Size 1	6" (Compac 6) or 12"
Size 2	12"
Size 3	18"
Size 4	21"
Size 5	42" (48" with thermal-magnetic breaker)
Size 6	72", full 20" x 20" section

Source: 8998CT9701 p. 34. Fusible feeders run taller: 30-100 A at 6" or 12", 200 A at 24", 400 A at 51", 600-800 A at 60", 1000-1200 A at 72" (p. 35). Unit extenders add 3" to 24"; total unit height cannot exceed 72".
Breaker feeder rating	Unit height
15-150 A (H frame)	6" Compac 6 or 12" plug-on
175-250 A (J frame)	6" Compac 6 or 18" plug-on
300-400 A	27" plug-on
450-600 A	36"
800 A	18" top entry, cabled
1200 A	21" cabled; 100%-rated 1200 A takes a full section

Three open Square D Model 6 circuit breaker branch feeder units — Square D Model 6 circuit breaker branch feeder units.

5. What is inside a current unit

Sources: Schneider Digest section 17; 80459-641-01 Rev 12 (frame and settings tables); iMCC brochure 8998BR0001. Communications on intelligent units: Modbus, Modbus TCP, EtherNet/IP via TeSys T, DeviceNet, PROFIBUS, CANopen.
Component	Current content	Legacy content still serviced
Motor circuit protectors	PowerPacT MCP in standard units; TeSys BV4 in Compac 6	Mag-Gard; settings procedures retained in 80459-641-01 Rev 12
Feeder and main frames	PowerPacT B, H, J, L, P, R; MasterPact NT, NW, and MTZ mains	FA, FC, KA, KC, LA and letter-frame families; torque data retained
Starters	Class 8536 Type S NEMA or D-Line IEC	Type S is the same class as the legacy population
Overload relays	Melting alloy, Motor Logic solid state, TeSys T, TeSys Tera motor management	Thermal unit selection rules unchanged
Drives and soft starts	Altivar drives (18-pulse to 400 HP variable torque), Altistart soft starts	Altivar 61/71 era equipment
Other unit content	PowerLogic metering, SPD units, AccuSine active harmonic filters, ASCO transfer switches, panelboards, transformers, high-resistance grounding

6. Reading a Model 6 catalog number

Merchandised combination starter units use an eight-segment structure. Example: 8998 SBA005AFTMA

Source: Schneider Digest section 17-4. Base ratings for merchandised units: 480 V, 60 Hz, NEMA 12, Type 1B wiring, 100 kA AIR. Branch feeders use five segments: 8998 + S/H + B or F + F (feeder) + amps, e.g. HBF015 (6-inch, 15 A) or SBF250 (18-inch, 250 A). Blank doors: 8998CP03 through 8998CP24 by inch.
Segment	Meaning	Codes
8998	Class	All Model 6 units
S / H	Unit family	S standard, H high density (Compac 6)
B / F	Disconnect	B circuit breaker (PowerPacT MCP; TeSys BV4 in Compac 6), F fusible (Class R clips; Class J in Compac 6)
A / C	Device	A FVNR, C FVR (FVR not available in Compac 6)
005	Motor HP	001 through 100; 15 HP and above not available in Compac 6
A / C / X	Pilot devices	X none, A start-stop pushbutton with lights, C HOA with lights
FT / FS	Control power	FT 480-120 V CPT, FS 120 V separate fused control
MA / SS	Overload	MA melting alloy (thermal units ordered separately), SS Motor Logic solid state

7. Arc flash and safety options

The AR rating is device-limited: it depends on the upstream protective device clearing within 50 ms (instantaneous at or below 35 kA), with short-time delay off, per the label text reproduced in 80459-641-01 Rev 12.
Option	What it is	Rating / document
Arc-Rated (AR) Model 6	Sections tested to contain an internal arc: reinforced 12-gauge doors, roof flaps, unit shelf pressure relief, insulated bus options, exhaust plenum option	ANSI/IEEE C37.20.7, Type 2 accessibility (front, sides, rear); 65 kA max, 600 V, 100 ms device-limited; IB 80459-654-01
ArcBlok 1200	Line-side cable vault isolating the incoming compartment; thermal monitoring of line-side conductors	100 kA at 480 V, 50 kA at 600 V, through 1200 A; brochure 8998BR1901
ArcBlok 2500	Larger ArcBlok main; documented in the current instruction bulletin with its own wiring, lacing, and post-arc-event maintenance procedures	80459-641-01 Rev 12 and 80459-641-04; published ratings pending
Closed Door Racking (CDR)	Rack a unit on or off the bus with the door closed	IB 80459-655-01; remote racking option operates outside the arc flash boundary
Absence of Voltage Tester (AVT)	Panduit AVT integrated in the unit	Brochure 8998BR1701
ERMS	Energy-reducing maintenance switching on applicable trip units	Brochure 8998BR1701
Automatic vertical bus shutters	Shutters close automatically as a unit is withdrawn	80459-641-01 Rev 12, Appendix C

8. Engineering data worth bookmarking

Sources: 80459-641-04 Rev 02 (insulation test); 8998CT9701 p. 11 (heat, altitude); 80459-641-01 Rev 12 (storage, seismic chapter); HCAI OSP-0052.
Topic	Values
Insulation test at commissioning	500-1000 V megohmmeter, all disconnects off; typical readings 5-20 megohms or higher; do not energize below 1 megohm. Disconnect drives, soft starters, SPDs, filters, and meters first.
Unit heat dissipation	Size 1 starter 270 BTU/hr (79 W); Size 5 starter 2,400 BTU/hr (700 W); 2500 A feeder 27,815 BTU/hr (8,150 W). Add 10% for 1200-1600 A bus, 20% for 2000-2500 A bus.
Altitude derating	At 8,500 ft: 0.99 current, 0.95 voltage. At 13,000 ft: 0.96 current, 0.80 voltage. VFD units: minus 1% output current per 330 ft above 3,300 ft.
Storage	75% relative humidity or less; minimum 200 W of heat per section against condensation.
Seismic	AC156 shake-table certified; HCAI (OSHPD) preapproval OSP-0052 through Aug 2028: SDS 1.88 g at roof, Ip 1.5, standard and relay sections including 3R.
Marine	ABS certification available for classed vessels and rigs (Schneider FAQ FA280117).

9. Obsolescence boundaries: what is still supported

Item	Status	Source
Model 6 structures and units	Current production	Schneider Model 6 range page
FA breakers in early Model 6 units	End of life; PowerPacT equivalents replace them	Schneider FAQ FA233980
KA frames (KA36100-250)	Replaced by PowerPacT HGA/JGA, same 4.5" mounting height	Schneider FAQ FA233980
PowerPacT H/J/L retrofits into existing buckets	Direct-mount conversion accessories: S429341 (H/J), S32606 (L), instruction GHD16295AA	Schneider FAQ FA294496
Mag-Gard MCPs, legacy letter frames	No longer current content, but settings and torque data retained in the live instruction bulletin; replace like for like from the catalog	80459-641-01 Rev 12
Model 5 handles, linkages, saddles	Obsolete from Schneider	FAQs FA127402, FAQ000269132
Model 4 structures	Unavailable since 2009; transition sections join Model 4 lineups to Model 6	Supplemental Digest 12

10. Ordering a Model 6 bucket: the complete checklist

This is the information that turns a call into a correct bucket. It is the same checklist we run on every order.

Step	What to determine	Where it comes from
1. Confirm the lineup	Model 6 vs Model 5 vs Model 4; see section 1	Handle style, fasteners, nameplate, or send photos
2. Unit function	Feeder, FVNR starter, FVR, VFD feeder, or special	The load. For drive retrofits see our VFD feeder reference
3. Disconnect and rating	Breaker vs fusible; amp rating or motor HP	Load calculations; drive manual maximum if feeding a VFD
4. Interrupting rating	Available fault current at the bus	Fault study. Our feeders ship 65 kAIC standard
5. Unit height	From the tables in section 4; match the slot being filled or consolidated	The existing unit and section space
6. Wiring class and type	Type B-D, B-T, or C termination	Plant standard; Type B is the common default
7. Pilot devices and control	PB/HOA/lights; CPT vs separate control	The control scheme
8. Options	Enclosure type, space heater, nameplate engraving, special paint	Site conditions

Lead time reality: Schneider's merchandised units ship in as little as 3 days but only in a limited 480 V / NEMA 12 matrix; RapidSource pre-engineered lineups run about 3 weeks; fully engineered orders are quote-driven (Digest section 17-4; brochure 8998BR1701; handout 8998HO2001). That gap is the reason our shop exists: we keep hundreds of Model 6 buckets in stock, build custom configurations every day in our UL 508A shop, and ship fast, complete units with breaker installed, door, and hardware. Configure a Model 6 bucket or send photos to [email protected].

The Model 6 document library

All are Schneider Electric publications, available from the se.com download center by document number.
Document	What it covers
8998CT9701R07/09	The full Model 6 catalog: unit tables, construction, typical specifications. Last full edition (2009); current selection data lives in the Schneider Digest, section 17
80459-641-01, Rev 12 (02/2026)	The living instruction bulletin: installation, torque tables, maintenance intervals, seismic chapter, breaker settings including legacy frames
80459-641-04, Rev 02 (10/2025)	Quick start guide: receiving, joining sections, bus splicing, ArcBlok wiring, pre-operation checklist, insulation testing
80459-654-01	Arc-Rated Model 6 instruction bulletin
80459-655-01	Closed Door Racking unit bulletin
80459-656-01	1600 A splice instructions
8998BR1701 (2021)	Current overview brochure: bus tiers to 3200 A, safety options, RapidSource
8998BR1901 (2019)	ArcBlok brochure with ratings
0110PD9201	Square D date code system
Supplemental Digest 12	Obsolete MCC section: Model 4 and Series 5600 support and transition sections

Values on this page are compiled from the Schneider documents cited under each table. Where editions disagree, the newer document governs and the change is noted. MCC Depot is an independent builder of new replacement units and is not affiliated with Schneider Electric.