| Single-Pole AC MCB | 1 pole | 120/230 V AC | 6–63 A | 6–10 kA at the declared voltage | Thermal overload and magnetic short-circuit protection; B, C, or D trip curve | IEC 60898-1 or the applicable national equivalent | 35 mm DIN rail | Lighting circuits, socket outlets, and small single-phase loads | Confirm line-side connection requirements, neutral arrangement, trip curve, terminal capacity, and local certification |
| Two-Pole AC MCB | 2 poles | 120/240 V or 230/400 V AC | 6–63 A | 6–10 kA at the declared voltage | Simultaneous protection and isolation of two conductors; thermal-magnetic operation | IEC 60898-1; verify compatibility with the target panel standard | 35 mm DIN rail | Single-phase circuits requiring two-pole isolation or line-to-line loads | Check whether both poles are protected, the pole pitch, busbar position, and handle-tie requirements |
| Three-Pole AC MCB | 3 poles | 230/400 V AC | 6–63 A | 6–10 kA at the declared voltage | Thermal-magnetic protection for three-phase branch circuits; B, C, or D trip curve | IEC 60898-1 or IEC 60947-2, depending on the declared use | 35 mm DIN rail | Three-phase motors, heaters, pumps, and commercial distribution circuits | Compare phase balance requirements, motor inrush tolerance, short-circuit rating, and coordination with upstream protection |
| Four-Pole AC MCB | 4 poles | 230/400 V AC | 6–63 A | 6–10 kA at the declared voltage | Three-phase plus neutral switching; neutral may be switched or protected according to design | IEC 60898-1 or IEC 60947-2 | 35 mm DIN rail | Three-phase systems requiring neutral isolation, transfer equipment, or full circuit disconnection | Verify neutral-pole construction, switching sequence, terminal markings, and suitability for the earthing system |
| RCBO with Overcurrent Protection | 1P+N or 2 poles | 120/230 V AC | 6–40 A | 6–10 kA at the declared voltage | Combined overload, short-circuit, and residual-current protection; common sensitivities include 30 mA | IEC 61009-1 or the applicable national equivalent | 35 mm DIN rail | Socket circuits, wet-area circuits, residential final circuits, and equipment requiring additional shock protection | Specify Type AC, A, F, or B residual-current detection as required; confirm sensitivity, selectivity, and neutral switching |
| DC MCB | 1, 2, or 4 poles | 60–250 V DC, depending on pole configuration | 1–63 A | Typically 6–10 kA DC, subject to the exact voltage and pole arrangement | Thermal-magnetic DC protection with a dedicated arc-extinguishing design | IEC 60947-2 or the relevant photovoltaic and DC protection standard | 35 mm DIN rail | Battery storage, control panels, telecommunications, and photovoltaic string or array circuits | Never substitute an AC-only breaker; verify DC polarity, maximum series voltage, interrupt rating, and reverse-feed capability |
| Compact Branch MCCB | 2, 3, or 4 poles | 240–600 V AC, depending on configuration | 63–250 A | 18–35 kA at the declared voltage | Adjustable or fixed thermal-magnetic protection; optional electronic trip units may be available | IEC 60947-2 or UL 489, depending on the target market | Panel or chassis mounted | Large commercial branch feeders, HVAC equipment, pumps, and small industrial distribution panels | Compare frame size, available settings, Icu and Ics values, lug size, accessories, enclosure space, and maintenance requirements |