ABB Emax2 Air Circuit Breaker Review and Full Specifications Guide

What is the ABB Emax2 air circuit breaker? The ABB Emax2 is a low-voltage air circuit breaker rated 400–6300 A up to 1000 V AC under IEC 60947-2, featuring the Ekip trip unit platform for integrated protection, measurement, and digital communication in main and tie-breaker applications. Specifying an Emax2 without correctly mapping Ekip trip unit grade to selectivity requirements — or overlooking Icu versus Ics ratings against prospective fault levels — risks failed cascade coordination, non-compliant protection discrimination, or unnecessary overrating costs. This guide covers the Emax2 versus original Emax architecture changes, the Ekip trip unit hierarchy, breaking capacity and selectivity cascade behavior, mechanical endurance ratings, IEC 61850 digital substation integration, and a direct technical comparison against the Schneider Masterpact MTZ and Siemens 3WL.

What Makes the Emax2 Different from the Original Emax?

The first time I specified an original Emax (the E1–E6 series, launched around 2002) was for a paper mill retrofit in 2009. It was a solid breaker. But by the time the ABB Emax2 landed in 2014, the gap had become obvious — particularly around metering accuracy and communications. Emax2 isn't a cosmetic refresh. ABB redesigned the trip unit platform, the contact system, and the auxiliary architecture.

The headline change is the Ekip Touch and Ekip Hi-Touch trip units, which embed a Class 1 power meter (per IEC 61557-12) directly into the breaker. You no longer need a separate multifunction meter on the switchgear door for most applications. That alone saves roughly €400–€600 per cubicle and frees up door space for HMI screens.

The second meaningful change is connectivity. Emax2 supports Modbus RTU/TCP, Profibus, Profinet, EtherNet/IP, and IEC 61850 natively through plug-in Ekip Com modules. For substation automation work, IEC 61850 GOOSE messaging on a low-voltage breaker was unusual in 2014 — now it's table stakes.

Frame sizes at a glance

The Emax2 family spans four frame sizes, each available in multiple performance grades (B, N, S, H, L, V, X) that define the breaking capacity:

In practice, the E1.2 frame replaced what used to require a molded-case breaker plus separate meter for outgoing feeders in the 630–1600 A range. The compact ABB 1SDA070701R1 E1.2B 630 Ekip Dip LI is a typical example we ship for motor control center incomers.

Understanding the Ekip Trip Unit Hierarchy

Engineers often overlook how much the trip unit choice drives total cost — not just of the breaker, but of the entire panel. For the ABB Emax2, ABB offers six Ekip variants, and picking the wrong one is the single most common specification error I see on project drawings.

Ekip Dip — the basic option

Ekip Dip uses physical DIP switches for setting protection thresholds. No display. It supports L (long-time), S (short-time), and I (instantaneous) functions in the LSI variant, or just LI in the cheaper version. We specify Ekip Dip for cost-sensitive feeders where the load profile is well known and won't change. Examples from our shipments: 1SDA070741R1 E1.2B 800 Ekip Dip LI and 1SDA070781R1 E1.2B 1000 Ekip Dip LI.

The trade-off: no metering, no event log, no communication. If the breaker trips at 02:00 on a Sunday, you'll know it tripped. You won't know why.

Ekip Touch and Ekip Hi-Touch

Ekip Touch adds a 4.3" color display, full LSIG protection (G = ground fault), Class 1 metering, and an SD card slot for event logging. Hi-Touch extends this with directional protection (67), under/over-voltage (27/59), under/over-frequency (81), and reverse power (32) — the kind of functions you'd traditionally find in a dedicated SEL or Siprotec relay.

For a co-generation plant we commissioned in Greece, we used Ekip Hi-Touch on the bus-tie precisely because we needed reverse-power blocking on the utility incomer. It saved us from adding two SEL-700G relays. Roughly €3,200 per cubicle in avoided cost, and one fewer point of failure.

Ekip G Touch and Hi-Touch

The "G" variants add generator protection functions per ANSI 27, 32, 40, 46, 50V, 51V, 59, 67, 81. If you're protecting a synchronous generator under 6300 A, this trip unit replaces a discrete generator protection relay. We've used it on EDG (emergency diesel generator) installations in hospitals where space inside the genset enclosure was limited.

Breaking Capacity, Selectivity, and the Cascade Question

This is where the ABB Emax2 earns its reputation. The performance grades (B/N/S/H/L/V/X) aren't marketing tiers — they reflect genuinely different contact and arc-chute designs validated to IEC 60947-2 Clause 8.3.

For a 2000 kVA, 415 V transformer at 6% impedance, you get roughly 46 kA prospective. An Emax2 E2.2N at 66 kA Icu handles that comfortably. Bump the transformer to 2500 kVA at 5.75% — now you're at about 60 kA, and the N grade is marginal. Specify the S grade (85 kA Icu) for headroom. This is the calculation procurement should be running before they sign off on the bill of materials. For a deeper walkthrough, see How to Size an Air Circuit Breaker.

Selectivity with downstream MCCBs

A common mistake is assuming selectivity is automatic because the upstream breaker has a higher rating. It isn't. Selectivity (per IEC 60947-2 §2.5.23) requires that for any fault current up to a defined limit, only the downstream device opens. With Emax2, ABB publishes selectivity tables for combinations with Tmax XT and SACE Formula. Use them. Don't guess.

For example: an E2.2 H 1600 A upstream of a Tmax XT5N 400 A is fully selective up to 36 kA when both are set per the published curve coordinates. Push beyond that and you get partial selectivity — both devices trip.

Mechanical Design, Ratings, and Real-World Endurance

The ABB Emax2 uses a stored-energy spring mechanism with a charging time of roughly 4 seconds via the motor operator. The mechanical endurance ratings are where it differentiates against the previous generation:

• E1.2: 25,000 mechanical operations, 12,500 electrical at In
• E2.2: 25,000 mechanical, 10,000 electrical
• E4.2: 20,000 mechanical, 8,000 electrical
• E6.2: 10,000 mechanical, 3,000 electrical

These figures matter for facilities that switch frequently — generator test routines, ATS (automatic transfer switch) applications, motor switching duty. In a hospital we audit annually, the Emax2 E2.2 used as the EDG output breaker logs roughly 300 operations per year (weekly tests plus monthly black-start drills). At that rate, the breaker has 30+ years of mechanical life. The contacts will erode from arcing long before the mechanism fails.

Withdrawable vs fixed

Withdrawable (cassette-mounted) versions cost roughly 25–35% more than fixed but allow hot-swap maintenance. For a Tier III data center where the SLA is 99.982% uptime, you specify withdrawable. For a manufacturing line that shuts down every Sunday, fixed is fine. There's no universal answer here — it depends on duty cycle and SLA.

Front, rear, and HR terminations

The "F F" suffix in part numbers (e.g., 1SDA070821R1 E1.2B 1250 F F) indicates front-front terminations. "F HR" means front-horizontal rear, which we see on E2.2 frames where bus bar geometry forces rear connections — for example, 1SDA070981R1 E2.2B 1600 Ekip Dip LI 3p F HR. Always confirm termination orientation with the panel builder before ordering. Wrong terminations mean either a returned breaker or a custom bus bar — both expensive.

Communications and the Digital Substation Question

I'll be blunt: most engineers don't fully use the communication capabilities they pay for. We've shipped hundreds of ABB Emax2 Ekip Touch breakers where the customer never enabled Modbus. That's roughly €350 of trip unit upgrade left on the table per breaker.

If you do plan to integrate, the Emax2 Ekip Com module slots into the trip unit and handles:

For data center applications specifically, the IEC 61850 module enables fast bus-transfer schemes between utility and UPS feeds via GOOSE messaging — sub-cycle response times that you simply cannot achieve over Modbus. We discuss this further in Air Circuit Breakers in Data Centers.

How Emax2 Compares to Schneider Masterpact MTZ and Siemens 3WL

Procurement teams ask this constantly, and the honest answer is: all three alternatives to the ABB Emax2 are credible. The differences are at the margins, but those margins matter when you're standardizing a fleet across 30 facilities.

Schneider's backward compatibility with Masterpact NW cassettes is genuinely useful for retrofits. ABB's metering ecosystem and connectivity is the strongest of the three in our experience. Siemens 3WL is the most conservative engineering — fewer features, very robust. For a head-to-head, see ABB vs Schneider vs Siemens ACB: Brand Comparison for Engineers.

Common Field Issues and How to Avoid Them

What we typically see in the field with the ABB Emax2 isn't catastrophic failure — it's commissioning errors and configuration drift.

Nuisance tripping on inrush

The most frequent service call: a 1600 A Emax2 trips when a 500 kVA transformer downstream is energized. The cause is almost always the instantaneous (I) pickup set too low, below the transformer inrush peak (typically 8–12× FLA for 0.1 seconds). The fix: raise the I setting, or use the I²t-on characteristic on the short-time function instead. We cover this systematically in Air Circuit Breaker Nuisance Tripping: Causes, Diagnosis and Fixes.

Earth-fault summation errors on TN-C-S systems

If the neutral CT is omitted on a 4-pole installation, the residual ground-fault function (G) reads zero current as fault current the moment load imbalance exceeds the threshold. Always specify the 4-pole version (or external neutral CT for 3-pole) when ground-fault protection is required on a TN-C-S system. Per IEC 60947-2 Annex F, the trip unit must measure all four conductors to compute residual current correctly.

Firmware mismatches

Ekip trip units have firmware. When you swap a unit in the field, the new module may not match the panel's commissioning records. We've seen sites where the spare trip unit was three firmware revisions behind, causing intermittent Modbus register mismatches with the BMS. Maintain a written firmware baseline per site. For broader standards context, refer to IEC 60947-2 for Air Circuit Breakers: Full Standard Breakdown.

Procurement Notes:Lead Times, Spares, and Lifecycle

The ABB Emax2 is a global product, but lead times vary significantly by configuration. Standard E1.2 frames with Ekip Dip ship from European stock in 1–2 weeks. E4.2 and E6.2 with Ekip Hi-Touch G and IEC 61850 modules can stretch to 14–18 weeks during peak demand cycles. Plan accordingly.

For frequently ordered configurations, we hold inventory on the most common SKUs at Stoklink — including the 1SDA070861R1 E1.2B 1600, 1SDA071021R1 E2.2B 2000, and the LSI variant 1SDA070702R1 E1.2B 630 Ekip Dip LSI. Browse the full air circuit breakers collection for current availability.

Spares strategy

For a fleet of 20+ Emax2 breakers, we recommend a 10% spare ratio on trip units (the most failure-prone component) and 5% on complete breakers. Critical sites should hold one spare per frame size. The trip unit is field-replaceable in roughly 15 minutes by a competent electrician — no specialized tools required.

Don't overlook auxiliary contacts and shunt trips. These mechanical accessories fail more often than the breaker itself, and ABB part numbers for auxiliaries are not interchangeable between Emax2 and the original Emax. Verify before substituting.

Lifecycle and obsolescence

ABB has committed to active production of Emax2 through at least 2030, with spare parts availability through 2040. The original Emax (E1–E6) entered "limited" status in 2022 — still available, but lead times have stretched and pricing has crept up. If you're standardizing a new fleet, Emax2 is the answer. If you're maintaining an existing Emax fleet, plan a transition strategy now rather than during a forced retrofit.

Cost-Benefit: When Emax2 Is Worth the Premium

An ABB Emax2 E2.2 with Ekip Touch costs roughly 2.5–3× a comparable Tmax XT MCCB at the same current rating. That's a real difference. Procurement managers push back on it constantly. The justification has to come from the system, not the device.

Three scenarios where Emax2 is unambiguously worth it:

Main incomers above 1600 A. At this rating, MCCBs run out of headroom on breaking capacity, and you need the air-break technology. Not optional.

Applications requiring embedded metering. If your project needs energy submetering for ISO 50001 compliance or tenant billing, the integrated Class 1 meter in Ekip Touch eliminates a separate device per circuit. The payback is typically 2–3 years.

Substation automation projects. If IEC 61850 is in the spec, the cost of bolting on a gateway to a cheaper breaker exceeds the Emax2 premium. Just buy the right tool.

Scenarios where Emax2 is overkill: simple distribution feeders below 1000 A with no metering or communication requirements. A Tmax XT5 with a basic thermal-magnetic trip unit will do the job for a third of the cost. Don't over-specify.

For applications outside the air circuit breaker range, browse the miniature circuit breaker, residual current device, and relay collections at Stoklink for the supporting protection ecosystem.

Related Reading

• What Is an Air Circuit Breaker? Working Principle Explained
• How to Size an Air Circuit Breaker: Step-by-Step Selection Calculator
• ABB vs Schneider vs Siemens ACB: Brand Comparison for Engineers
• Air Circuit Breaker Nuisance Tripping: Causes, Diagnosis and Fixes

Conclusion: When Emax2 Earns Its Place in the Spec

The ABB Emax2 is not the cheapest air circuit breaker, and it's not always the right answer. But for main incomers above 1600 A, applications requiring embedded Class 1 metering, and any project specifying IEC 61850 substation automation, it consolidates functions that would otherwise require multiple devices. The Ekip trip unit ecosystem — particularly Hi-Touch with its directional and generator protection functions — replaces dedicated protection relays in many configurations, and that's where the real cost savings emerge.

The most common specification mistakes we see are over-specifying trip units on simple feeders, under-specifying breaking capacity grade on transformer outputs, and ignoring termination orientation on ordering. Get those three right and the breaker performs as advertised for 20+ years.

For the full selection methodology covering frame sizing, coordination, and maintenance planning across all ACB families, see our Air Circuit Breaker Guide: How It Works, Selection, Sizing and Maintenance. For pricing and stock on specific Emax2 SKUs, the Stoklink air circuit breakers collection lists current availability across the E1.2, E2.2, and E4.2 frames.