ABB SACE Emax 2: Best Low Voltage Air Circuit Breaker for Industry 2024

What is the ABB SACE Emax 2? The ABB SACE Emax 2 is a withdrawable low-voltage air circuit breaker rated 400–6300 A under IEC 60947-2, offering breaking capacities up to 150 kA and an integrated Ekip trip unit platform for protection, measurement, and communication. Specifying the wrong frame size, miscalculating Icw-rated short-time withstand, or selecting an undersized Ekip module forces costly retrofits and exposes switchgear to non-compliant protection coordination. This guide covers why the Emax 2 leads the LV ACB market, head-to-head comparisons with competing brands, frame sizing calculations, Ekip trip unit selection without overspending, real-world application contexts, and documented failure modes with mitigation strategies.

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

Why the Emax 2 Leads the LV Air Circuit Breaker Market

Walk into any modern automotive plant, data center, or chemical facility commissioned in the last five years and look at the incoming MV/LV substation. Odds are the main breaker is either an ABB SACE Emax 2 or a Schneider MasterPact MTZ. There is a reason for that duopoly, and it is not branding.

The Emax 2 was the first low voltage air circuit breaker (ACB) to integrate active power management into the trip unit itself. Before its release, energy metering and load shedding required separate meters, PLC logic, and a small forest of CTs. With the Ekip Hi-Touch and Ekip G Touch units, the breaker became a measuring instrument, a controller, and a protective device at once. That collapsed cabinet space, reduced wiring errors, and — more importantly — gave plant operators real-time visibility into the largest energy users on their bus.

In our experience commissioning industrial MDBs across Europe and the Middle East, the Emax 2's biggest practical advantage is not the protection curves. Every serious manufacturer offers L-S-I-G protection now. The advantage is the Ekip Connect ecosystem, which lets you commission, parameter, and diagnose the breaker over Bluetooth from a tablet without removing the trip unit. On a 1600 A breaker buried in the back of a substation, that matters.

What Engineers Actually Buy in

Looking at order data across our customer base, the most common Emax 2 frame for industrial new-builds is the E2.2 in the 1600–2500 A range, with Ekip Dip LSI as the entry-level trip unit. The ABB 1SDA070981R1 E2.2B 1600 Ekip Dip LI is a typical incomer for a 1250 kVA transformer at 400 V. Smaller plants — workshops, pumping stations, water treatment skids — gravitate to the E1.2 frame, where the ABB 1SDA070701R1 E1.2B 630 and ABB 1SDA070741R1 E1.2B 800 dominate.

Detailed technical specifications, performance ratings, and trip unit configurations for the ABB SACE Emax 2 are documented in the manufacturer's official ABB SACE Emax 2 product portfolio, which aligns with the IEC 60947-2 low voltage switchgear standard.

How Does the Emax 2 Compare to Other LV ACB Brands?

The honest answer: in pure protection terms, the top four — ABB SACE Emax 2, Schneider MasterPact MTZ, Siemens 3WL, and Mitsubishi AE-SW — are technically equivalent for 95% of industrial applications. The differences appear in software, accessories, and lead times. We covered this in detail in our ABB Emax 2 vs Schneider MasterPact MTZ comparison, but here is the executive summary.

The Siemens 3WL has marginally better short-time withstand (Icw) figures in some frames, which matters for selectivity in deep cascades. The MasterPact MTZ has the slimmest frame, useful when retrofitting older switchgear. The Emax 2 wins on availability and on the breadth of the Ekip family — there are nine trip unit variants ranging from a basic Dip LI to a Hi-Touch with embedded harmonic analysis.

Where Procurement Managers Get It Wrong

A common mistake is comparing breakers on unit price alone. A 1600 A ACB is roughly 8–15% of the cost of a complete LV switchboard. The real cost driver is what you bolt around it: CTs, meters, BMS gateways, and the labor to wire them. When the Ekip Touch trip unit replaces a separate Class 1 power meter and a small PLC, the all-in cost difference between brands shrinks to noise.

Sizing the Emax 2: The Calculation That Actually Matters

Engineers often overlook that ACB sizing — including for the ABB SACE Emax 2 — is not just about the load current. You are sizing for three things simultaneously: continuous current carrying capacity (In), prospective short-circuit current (Icc), and selectivity with downstream devices. Get any one wrong and you have a problem.

The continuous current calculation is the easy part. Take the transformer secondary full-load current, apply derating for ambient temperature, and pick the next standard frame up. For a 1600 kVA, 400 V transformer:

For a 1600 kVA / 400 V transformer, In = 1,600,000 / (1.732 × 400) = 2309 A. You would not pick a 2500 A frame here — you would pick the 2500 A E2.2 only if you have a hard ceiling, otherwise step up to the E4.2 at 3200 A to leave headroom for harmonic loading and future expansion. This is exactly the kind of decision the step-by-step Emax 2 sizing calculator walks you through.

The short-circuit calculation is where mistakes happen. The prospective short-circuit current at the secondary terminals of a transformer is:

For our 1600 kVA transformer with uk = 6%, Icc = 2309 × 100 / 6 = 38.5 kA. The 42 kA E2.2B version covers it. But — and this is where engineers stumble — if the plant has parallel transformers or upstream MV contribution, the Icc on the bus can climb to 60+ kA, and you need the E2.2N (66 kA) or even an H or V version. Always check the upstream impedance contribution.

The 80% Rule and Continuous Loading

Per IEC 60947-2 §4.3.2.3, an ACB rated for category B can carry its full rated current continuously at 40 °C ambient. In practice, panel ambient at the trip unit can hit 55 °C in a closed substation in summer. Above 50 °C, you start to see derating — typically 5–8% on the In setting. We size at 80% of frame current as a working rule, leaving 20% headroom for ambient and harmonics.

The Ekip Trip Unit Family: Choosing Without Overspending

This is where most procurement decisions for the ABB SACE Emax 2 get bogged down. ABB offers Ekip Dip, Ekip Touch, Ekip Hi-Touch, and Ekip G Touch, each in LI, LSI, LSIG, and LSIG with measurement variants. The catalog has roughly 40 part numbers per frame. Here is how to cut through it.

If your application is a simple feeder breaker — a motor control center incomer, a sub-distribution feed — you want Ekip Dip LSI. The ABB 1SDA070782R1 E1.2B 1000 Ekip Dip LSI is the workhorse here. DIP switches on the front, no display, no communication. Set the curves once and walk away. Cheap, robust, no firmware to worry about.

If the breaker is the main incomer and you want energy data, you need Ekip Touch with the measurement (M) package. This adds a 4-line LCD, three-phase voltage and current measurement, energy registers, and Modbus RTU. About 25% more expensive than Dip, but you save the cost of a separate Class 1 meter.

If the breaker sits in a critical bus — data center, hospital, pharmaceutical — you go to Ekip Hi-Touch with G Touch. You get harmonic analysis up to the 50th, waveform capture on trip events, dual setting groups for source changeover, and embedded IEC 61850 GOOSE for fast bus transfers. We discuss the data center application pattern in detail in our note on Emax 2 in data center MDB design.

A Word on Ekip Connect

The Ekip Connect Bluetooth dongle (Ekip Com R or the newer Ekip Up) plugs into the front of the trip unit and pairs with a phone or laptop. You can read settings, push parameters, download trip logs, and run a test trip — all without opening the panel door. For maintenance crews, this is a substantial safety improvement: arc flash exposure goes to zero during routine parameter checks.

Real-World Applications: Where Engineers Specify Emax 2

Automotive Stamping Plant, Eastern Europe

A 2500 kVA, 400 V transformer feeds a press shop with 1500 A continuous load and large inrush from servo presses. We specified an ABB SACE Emax 2 E2.2N 2500 with Ekip Touch LSIG, set with selectivity to downstream ABB 1SDA070861R1 E1.2B 1600 feeders for the press lines. The harmonic measurement on the Ekip Touch caught a 14% THDi from the servo drives in commissioning, leading to a passive filter retrofit before damage to the transformer.

Pharmaceutical Cleanroom, Ireland

Validation requirements meant every electrical event had to be timestamped and logged. We used three E2.2B 2000 ACBs (ABB 1SDA071021R1 E2.2B 2000) with Ekip Hi-Touch and IEC 61850. The waveform capture and 1 ms time stamping satisfied 21 CFR Part 11 audit trails without an external power quality meter.

Water Treatment Plant, Middle East

Ambient temperatures in the substation hit 58 °C despite air conditioning. We sized down: the rated load was 750 A, but we specified an ABB 1SDA070821R1 E1.2B 1250 rather than the 800 A frame, with the In setting at 0.6. This gave thermal headroom and extended contact life. Three years in, no nuisance trips.

Common Failure Modes and How to Avoid Them

The ABB SACE Emax 2 is reliable, but it is not immune to the field problems that plague every ACB: nuisance tripping, neutral CT errors, communication dropouts, and contact wear. Most of these are installation or commissioning issues, not equipment defects.

The most common issue we see is nuisance tripping on inrush. A typical scenario: a 1000 A breaker (ABB 1SDA070781R1 E1.2B 1000) feeding a transformer-loaded UPS bank trips on energization because the instantaneous (I) setting is at 6× In. The fix is straightforward: raise the I setting to 10–12× In, or switch to LSI with the short-time delay set above the inrush envelope. We have a full diagnostic guide for these scenarios in our article on Emax 2 nuisance tripping root causes.

The second most common issue is neutral conductor protection on 4-pole breakers. If you specify a 4P breaker but only run a 3P+N system with the neutral undersized, the Ekip will read unbalanced current and trip on ground fault. Either size the neutral at 100% or set the N pole protection to 50% explicitly in the trip unit.

Standards Compliance and Certification in

The ABB SACE Emax 2 is type-tested to IEC 60947-2 (general requirements), IEC 60947-1 (basic standard), and IEC 60947-4-1 where used in motor circuits. For North American projects, the same frames are available with UL 1066 listing — the Emax 2 UL family — and meet ANSI C37.50 testing. For maritime and offshore, type approvals from DNV, ABS, Lloyd's Register, RINA, and BV are available on request.

For functional safety, the Ekip Touch with Safety package carries a SIL 2 certification per IEC 61508 for the trip function. This matters in process industries where the LV main is part of the safety instrumented system.

Per IEEE C37.13 — the U.S. equivalent for low voltage power circuit breakers — short-time current ratings are stated for 0.5 s rather than the IEC 1 s. The Emax 2 UL versions publish both ratings to ease cross-referencing for engineers working on dual-standard projects.

Total Cost of Ownership: The 15-Year View

Procurement managers tend to evaluate ACBs like the ABB SACE Emax 2 on capital cost. Plant managers, who pay the maintenance bills, evaluate them on lifecycle cost. The two views rarely align in the bid stage, and that misalignment costs money over the life of the installation.

An Emax 2 E2.2 at 2000 A has a mechanical life of 25,000 operations and an electrical life of 10,000 operations at full rated current. For a typical industrial main breaker that operates twice a year for routine testing and never trips on full fault, that is effectively unlimited life. The wear items are the auxiliary contacts, the springs in the closing mechanism, and the trip unit battery (where fitted).

The maintenance regime per IEC 60947-2 Annex K recommends:

A visual inspection every 12 months, a functional test every 24 months, and contact resistance measurement every 60 months or 5000 operations. The Ekip Touch can run a "trip test" from the front panel without de-energizing the bus, which means the 24-month functional check takes 15 minutes per breaker instead of a half-day shutdown. Across a fleet of 30 ACBs in a large plant, that is a real cost saving.

Spare parts strategy matters too. Because the Emax 2 trip unit is a swappable module, you can stock one or two Ekip Touch units as plant spares and cover any breaker in the family. The Emax 2 technical specifications guide lists the part number cross-references between frames and trip units.

Where Emax 2 Fits in the Wider Protection Scheme

An ACB such as the ABB SACE Emax 2 is not an island. It sits at the top of a protection cascade that runs down through molded case breakers, then to miniature circuit breakers at the final circuit level, and often includes residual current devices for personnel protection. Coordination across this cascade is what keeps a single fault from blacking out the plant.

The Emax 2's L-S-I-G curves are designed for selectivity with downstream MCCBs (Tmax XT or T series from ABB) and MCBs. The short-time delay (S) is the key parameter: setting it at 200–400 ms with an Icw of 42 kA gives downstream breakers time to clear faults on their own circuits without taking down the bus.

For motor feeders, coordination with thermal overload relays and contactors follows IEC 60947-4-1 §8.2.5.1 — Type 2 coordination, which guarantees no damage to the contactor or overload under fault conditions. The Emax 2 does not directly protect the motor; that is the contactor and overload's job. The ACB protects the bus.

For a deeper view of the full ACB ecosystem and how the Emax 2 sits among ABB's other offerings, see our overview of what the ABB SACE Emax 2 is and its features, or browse the full range of air circuit breakers at Stoklink.

Procurement Reality: Lead Times, Counterfeits, and Spares

2024 lead times for genuine ABB SACE Emax 2 stock from ABB factories run 4–8 weeks for standard configurations and 12–16 weeks for special variants (UL listed, marine certified, special accessories). For project schedules that cannot absorb that, working with a stocking distributor cuts delivery to days, not weeks.

A note on counterfeits: the Emax 2 has been targeted by counterfeit operations, particularly in markets where pricing pressure is high. The giveaway signs are mismatched serial numbers between the breaker frame and the trip unit, missing CE/UL holographic stickers, and Ekip Connect Bluetooth that fails to authenticate against ABB's cloud. Always source through authorized channels and verify the serial number through ABB's product registry before commissioning.

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 vs Schneider MasterPact MTZ: Technical Specs, Features and Price Compared

Conclusion

The ABB SACE Emax 2 earns its position as the leading low voltage air circuit breaker for industrial use in not because it has the highest breaking capacity or the cheapest unit price, but because it integrates protection, metering, communication, and diagnostics in a way that reduces the total cost of an LV switchboard. For engineers, that means simpler panels, fewer wiring errors, and faster commissioning. For procurement managers, it means shorter lead times and a single supplier for breaker, meter, and gateway functions.

The decision framework is straightforward. Start with the transformer rating to pick the frame. Verify the prospective short-circuit current to pick the breaking capacity class. Match the trip unit to the application — Ekip Dip for simple feeders, Ekip Touch for incomers needing energy data, Ekip Hi-Touch for critical buses with power quality requirements. Coordinate the protection curves with downstream devices using IEC 60947-2 selectivity tables. Specify accessories — auxiliary contacts, motor operators, undervoltage releases — based on the operational scheme.

For the full selection methodology, including detailed coordination tables, accessory part number lists, and commissioning checklists, see the ABB SACE Emax 2 Air Circuit Breaker: Selection, Application and Maintenance Guide. The right Emax 2 specification, made once at the design stage, pays back across 25 years of plant operation.