ABB SACE Emax 2 Types and Models: Complete Range Guide for Engineers

What is the ABB SACE Emax 2? The ABB SACE Emax 2 is a low-voltage air circuit breaker range rated 400–6300 A under IEC 60947-2, available across four frame sizes (E1.2, E2.2, E4.2, E6.2) with breaking capacities up to 200 kA and six performance classes (B, N, S, H, L, V). Mismatched frame selection, incorrect performance class specification, or an incompatible Ekip trip unit assignment can compromise fault discrimination, violate coordination studies, and trigger costly retrofit work. This guide covers frame size current boundaries, performance class Icu ratings, fixed versus withdrawable mounting trade-offs, Ekip trip unit variants, terminal configurations (F, FC Cu, R, HR, VR), and 3-pole versus 4-pole selection criteria.

Published: 2026-04-27 | Last updated: 2026-04-27 | By Stoklink Engineering Team

Most of what gets specified wrong on Emax 2 happens in the first thirty minutes of a project — when someone copies a part number from an old single-line and forgets that the second-generation frames changed footprint, busbar geometry, and accessory keying versus the original Emax. We see this on at least one tender per quarter. The cost of that mistake compounds through the panelboard build, so the goal here is to give you a working map of the range before you commit a part number to paper.

What are the four frame sizes of the ABB SACE Emax 2?

The ABB Emax 2 is built around four mechanical frames. They are not interchangeable. Each frame defines the maximum continuous current, the breaking capacity ceiling, the physical envelope, and the accessory ecosystem.

E1.2 — 630 A to 1600 A

The smallest frame in the second-generation range, and the one that did the most to compress switchgear footprint. The E1.2 covers 630, 800, 1000, 1250, and 1600 A in a footprint of roughly 296 mm wide for the three-pole fixed version. That matters when you're trying to fit a main breaker plus outgoing feeders in a 600 mm column.

Common SKUs we ship for this frame include the ABB 1SDA070701R1 E1.2B 630 Ekip Dip LI 3p F F for sub-feeder duty, the ABB 1SDA070741R1 E1.2B 800 Ekip Dip LI 3p F F at 800 A, and the ABB 1SDA070781R1 E1.2B 1000 Ekip Dip LI for typical secondary distribution.

E2.2 — 800 A to 2500 A

The workhorse. Most main breakers on 1000–1600 kVA dry-type transformers end up here. The frame supports 800, 1000, 1250, 1600, 2000, and 2500 A, and the higher performance classes (N, S, H, L) reach up to 100 kA Icu at 415 V. For a 2000 kVA transformer at 400 V producing roughly 2887 A nominal, the E2.2 2500 is the natural fit. The ABB 1SDA070981R1 E2.2B 1600 Ekip Dip LI with horizontal rear terminals is what we typically see in switchboard backplanes.

E4.2 — 3200 A to 4000 A

For 2500–3150 kVA transformer mains and large generator paralleling. Above 3200 A, busbar bracing inside the panel becomes a bigger design concern than the breaker itself. Engineers often overlook the busbar derating at 50 °C ambient — IEC 60947-1 Annex H gives the basis, and most panel builders will quietly oversize the bar by one section.

E6.2 — 5000 A to 6300 A

Process plants, marine main switchboards, large data center MV/LV substations. At 6300 A you are pushing what an LV breaker can do thermally; the E6.2 uses an active arc-runner geometry and silver-tungsten contacts to handle the duty. Selection here is rarely a catalog exercise — it is a coordination study.

For complete technical documentation on the ABB Emax 2 air circuit breaker family, including frame ratings, Ekip trip unit configurations, and compliance with IEC 60947-2, refer to the ABB SACE Emax 2 product portfolio.

What are the performance classes (B, N, S, H, L, V)?

Within each ABB Emax 2 frame, ABB offers performance classes that govern breaking capacity. They are stamped on the nameplate after the frame letter — for example, E2.2N or E4.2H.

A common mistake is to pick the class purely from the prospective short-circuit current Ik" calculated upstream. The relevant question is what the breaker must interrupt after upstream impedance is included. On a 2 MVA / 6% Z transformer, the actual Ik" at the LV busbar is around 48 kA — a B class is marginal, an N class is the sensible engineering choice. For deeper coordination, the full technical specifications, ratings and dimensions reference covers Ics and Icw values per class.

Fixed vs withdrawable: which version when?

Every ABB Emax 2 frame ships in two mechanical versions. The choice has more to do with maintenance philosophy than electrical performance.

Fixed (F)

Lower cost, smaller envelope, terminals bolted directly to the busbar. We use fixed versions for sub-feeders that will not be replaced during the panel's life — secondary distribution, motor control center incomers below 1600 A, captive process loads. The ABB 1SDA070821R1 E1.2B 1250 Fixed is a typical example.

Withdrawable (W)

Cassette-mounted, with primary and secondary disconnects engaging when racked in. Withdrawable adds about 80 mm in depth and 20–25% in unit price, but lets you isolate, test, and replace the breaker without de-energizing the busbar. For any main incomer above 2000 A, or any breaker feeding a continuous-process plant, this is non-negotiable in our experience.

What are the Ekip trip unit options?

The trip unit is where the ABB Emax 2 separates itself from older designs. ABB offers a tiered family — Ekip Dip, Ekip Touch, Ekip Hi-Touch, and Ekip G Touch — each with protection function suffixes (LI, LSI, LSIG, LSIRc).

Protection function codes

The letters after "Ekip" tell you what's protected:

An LI trip unit gives you long-time and instantaneous only — fine for an end feeder, useless for a main breaker that needs to be selective with sub-feeders. For a transformer main, you almost always want LSI or LSIG. The ABB 1SDA070782R1 E1.2B 1000 Ekip Dip LSI is the LSI variant of the same 1000 A frame, and it is what we specify when a downstream MCCB needs a selective time grading.

Ekip Dip

The entry-level trip unit. DIP-switch settings, no display, no measurement. It does the protection job, nothing more. Use it where the panel never needs to report data — small industrial sites, replacement projects, captive loads.

Ekip Touch and Hi-Touch

Color touchscreen, full metering (V, I, P, Q, S, PF, THD up to 50th harmonic), event logging, and modular communication slots (Modbus RTU/TCP, Profibus, Profinet, EtherNet/IP, IEC 61850). The Hi-Touch adds waveform capture and higher accuracy class. For any switchboard tying into a building management system or SCADA, this is the practical floor.

Ekip G Touch

Adds dual-setting protection (G1/G2) for genset paralleling — different curves for grid-connected vs island operation. Critical for hospitals, data centers, and any installation with on-site generation.

Terminal configurations: F, FC Cu, R, HR, VR

The two letters at the end of an ABB Emax 2 SKU describe the terminals — and this is where part-number errors most often hide.

• F — Front terminals (vertical, breaker face)
• FC Cu — Front terminals for copper cable connection
• R — Rear terminals, vertical orientation
• HR — Horizontal rear terminals
• VR — Vertical rear terminals (alternate geometry)

The ABB 1SDA070861R1 E1.2B 1600 F F is front/front; the ABB 1SDA071021R1 E2.2B 2000 F HR is fixed with horizontal rear — designed for back-connected switchgear where busbars run horizontally behind the breaker. Get this wrong and the breaker physically cannot bolt to the busbar. We have seen entire shipments delayed because a procurement spec listed "F F" when the panel was built for "F HR".

3-pole vs 4-pole: when do you actually need the neutral pole?

Three-pole ABB Emax 2 covers most three-phase loads where the neutral is solidly grounded and not switched. Four-pole is required when:

The neutral conductor carries significant current and must be protected (TT systems, IT systems, or TN-S where neutral fault detection matters). Generator paralleling switches where the neutral must be opened for safe transfer. Installations under local codes (some Middle East and African jurisdictions mandate four-pole on incomers regardless of grounding system). Harmonic-rich loads — VFDs, UPS, LED lighting — where third-harmonic neutral current can exceed phase current. We have measured 1.4× phase current on a neutral feeding a data center PDU. A three-pole breaker would not see that current at all.

For a deeper sizing walkthrough, see how to size ABB Emax 2 step-by-step, which covers ambient derating and harmonic factors that this quick estimator skips.

How does Emax 2 compare to alternatives in real selection?

In practice, Emax 2 competes head-to-head with Schneider MasterPact MTZ and Siemens 3WL. The mechanical differences are smaller than marketing implies; the meaningful differences are in the trip unit ecosystem and the spare-parts logistics. We have rebuilt switchboards where the original specifier picked an MTZ in a region where ABB had three service centers and Schneider had none — that decision cost the client three weeks of downtime on a routine trip unit replacement. The full breakdown is in ABB Emax 2 vs Schneider MasterPact MTZ.

For the introductory background on the platform itself, what is the ABB SACE Emax 2 covers the genealogy from the original Emax through to the current generation.

Where does Emax 2 fit in real industrial facilities?

Three scenarios cover most of what we ship in the ABB Emax 2 range.

Scenario 1: 1600 kVA transformer in a manufacturing plant

Nominal secondary current at 400 V is 2309 A. With 25% headroom for thermal derating in a 45 °C panel, you need at least 2886 A continuous capacity — an E2.2 3200? No, the next step up. Here you would specify an E4.2 frame at 3200 A, performance class N (66 kA Icu covers the 42 kA prospective fault), withdrawable, with Ekip Touch LSIG. Add Modbus TCP for the plant SCADA.

Scenario 2: Data center main distribution board, 2N topology

Each utility feed has its own E4.2 main, plus an E4.2 generator paralleling breaker, plus tie breakers. Trip units must coordinate selectively across four cascaded levels, which forces LSIG with zone selective interlocking (ZSI). The full design considerations are in ABB Emax 2 in data centers: MDB design and uptime considerations.

Scenario 3: Marine main switchboard at 690 V

E6.2 6300 A on the main bus tie, classification society approved (DNV, Lloyd's, ABS). Mechanical interlocks between port and starboard mains. Withdrawable mandatory.

Common selection mistakes — and how to avoid them

Some patterns repeat across ABB Emax 2 projects.

Undersized Icu on parallel transformers. Two 2000 kVA units in parallel give you nearly double the prospective fault current at the bus. A class N breaker that handled one transformer cannot necessarily handle two.

Wrong terminal type on retrofit projects. Replacing an original Emax E2 with an Emax 2 E2.2 looks one-for-one in the catalog. The connection geometry differs. Always order a retrofit kit (ABB part code suffix RH) when going generation-to-generation.

Trip unit too basic for the application. Specifying Ekip Dip LI on a main breaker because "we don't need metering" — then discovering during commissioning that the upstream relay needs a delayed short-circuit setting that LI cannot provide. The Emax 2 nuisance tripping guide covers the field symptoms that follow.

Ignoring ambient derating. Per IEC 60947-2 §B.8.2, continuous current is given at 40 °C ambient inside the enclosure. At 55 °C, derate by roughly 12% on most frames. Engineers often spec for 40 °C and install in a 50 °C plant room — the breaker survives, but trips earlier than expected on long-duration overloads.

Related Reading

• What Is the ABB SACE Emax 2? Features, Models and Key Benefits
• ABB Emax 2 Full Technical Specifications: Current Ratings, Breaking Capacity and Dimensions
• How to Size ABB Emax 2: Step-by-Step Calculator for LV Distribution Panels
• ABB Emax 2 Nuisance Tripping: Root Causes, Diagnostic Steps and Fixes

If you need to extend the search beyond the ABB Emax 2, our broader Air Circuit Breakers collection covers the full LV ACB inventory at Stoklink, with adjacent product families like miniature circuit breakers, residual current devices, and protection relays for the downstream side of the same switchboard.

Conclusion

The Emax 2 range is broader than a part-number list suggests. Four frames, six performance classes, two mechanical versions, four trip-unit families, five terminal codes, and three or four poles — the combinatorics run into the thousands. What separates a good specification from a bad one is not knowing every SKU, but knowing which axes matter for your specific application. The frame ceiling sets your future expansion path. The performance class sets your fault-survival margin. The trip unit determines whether you can coordinate selectively with downstream devices and feed data to a building or plant management system. The terminal type determines whether the breaker bolts into the panel on day one. Get those four right and the rest follows.

For most industrial work, the practical sweet spot is an E2.2 N frame, withdrawable, with Ekip Touch LSIG and rear terminals matched to the switchgear. For data centers and process plants you step up to E4.2; for marine and heavy industry, E6.2. For everything below 1600 A in non-critical service, the E1.2 fixed family covers the spread economically.

Selection is only the first step — coordination, commissioning, and maintenance carry equal weight over the breaker's twenty-five-year service life. For the full selection methodology including time-current curve setting, ZSI wiring, and preventive maintenance intervals, work through the ABB SACE Emax 2 Air Circuit Breaker: Selection, Application and Maintenance Guide, and use the broader air circuit breaker engineering guide as the standards reference for IEC 60947-2 and IEEE C37 compliance considerations across competing platforms.