Device Type
Miniature Circuit Breakers (MCB)
IEC 60898 / UL 489
Low-voltage circuit breakers for residential, commercial, and light industrial applications. Typically rated up to 125A. Provide both thermal (overload) and magnetic (short-circuit) protection.
Standard
IEC 60898-1
Ratings
16 values
Standard Ampere Ratings
IEC 60898-1| Rating (A) | Typical Applications |
|---|---|
| 1 | Lighting circuits, very low load |
| 2 | Control circuits, low power |
| 4 | Lighting, small appliances |
| 6 | Lighting circuits (common) |
| 10 | Lighting, general purpose (common) |
| 13 | UK standard for socket outlets |
| 16 | Socket outlets, small motors (very common) |
| 20 | Air conditioners, water heaters |
| 25 | Large AC units, cooktops |
| 32 | Electric showers, ovens (common) |
| 40 | Main feeders, large loads |
| 50 | Main distribution, EV charging |
| 63 | Main breaker, sub-panels |
| 80 | Industrial, large feeders |
| 100 | Main service entrance |
| 125 | Maximum standard MCB |
Selection Notes
- • Curve types: B (lighting), C (general), D (motors/high inrush)
- • Breaking capacity: Typically 6kA (residential) or 10kA (industrial)
- • Common sizes: 6A, 10A, 16A, 20A, 25A, 32A for most applications
- • IEC 60898: Household and similar; IEC 60947-2 for industrial
Device Type
Molded Case Circuit Breakers (MCCB)
IEC 60947-2 / UL 489
Higher capacity breakers for industrial and commercial distribution. Adjustable trip settings available. Used for motor protection, feeder circuits, and main distribution.
Standard
IEC 60947-2
Ratings
25 values
Standard Ampere Ratings
IEC 60947-2| Rating (A) | Typical Applications |
|---|---|
| 10 | Small motors, branch circuits |
| 15 | Motor loads |
| 16 | Standard branch |
| 20 | Motor protection |
| 25 | Feeder circuits |
| 30 | Standard industrial |
| 32 | Motor feeders |
| 40 | Distribution feeders |
| 50 | Large motors |
| 60 | Industrial feeders |
| 63 | Standard MCCB size |
| 80 | Main feeders |
| 100 | Distribution mains (common) |
| 125 | Panel mains |
| 150 | Large distribution |
| 160 | Standard industrial |
| 200 | Main distribution (common) |
| 225 | Large feeders |
| 250 | Service entrance |
| 300 | Industrial mains |
| 315 | Standard rating |
| 350 | Large industrial |
| 400 | Main distribution (common) |
| 500 | High capacity |
| 630 | Maximum standard MCCB |
Selection Notes
- • Adjustable trip: Many MCCBs offer adjustable Ir (overload) and Im (short-circuit)
- • Breaking capacity: 25kA to 100kA typical; check fault current
- • Electronic trip: Advanced protection with ground fault, zone interlocking
- • Common sizes: 100A, 160A, 200A, 250A, 400A, 630A
Device Type
NH / HRC Fuses (DIN 43620)
IEC 60269
High rupturing capacity (HRC) fuses for industrial applications. Size-coded (00, 0, 1, 2, 3, 4a) with standardized dimensions. Used in main distribution and high fault current applications.
Standard
IEC 60269 / DIN 43620
Ratings
24 values
Standard Ampere Ratings
IEC 60269 / DIN 43620| Rating (A) | Typical Applications |
|---|---|
| 2 | Size 00, control circuits |
| 4 | Size 00, small loads |
| 6 | Size 00, lighting |
| 10 | Size 00/0, general purpose |
| 16 | Size 0, motors |
| 20 | Size 0, feeders |
| 25 | Size 0, distribution |
| 32 | Size 0/1, motors |
| 35 | Size 1, standard |
| 40 | Size 1, common |
| 50 | Size 1, feeders |
| 63 | Size 1, distribution |
| 80 | Size 1/2, motors |
| 100 | Size 2, common |
| 125 | Size 2, distribution |
| 160 | Size 2, main feeders |
| 200 | Size 2/3, industrial |
| 224 | Size 3, standard |
| 250 | Size 3, common |
| 315 | Size 3, distribution |
| 355 | Size 3, large |
| 400 | Size 3/4, main |
| 500 | Size 4, high capacity |
| 630 | Size 4, maximum standard |
Selection Notes
- • Size codes: 00 (small), 0, 1, 2, 3, 4 (large) - check physical dimensions
- • gG type: General purpose; aM type for motor protection
- • Breaking capacity: Up to 120kA - excellent for high fault current
- • Common sizes: 35A, 50A, 63A, 100A, 160A, 200A, 250A, 400A, 500A
Device Type
IEC Preferred Numbers (R10/R20)
IEC 60059
Standard preferred number series for electrical equipment ratings. Based on geometric progression ensuring optimal coverage. R10 series (1.25 ratio) and R20 series (1.12 ratio) are most common.
Standard
IEC 60059
Ratings
21 values
Standard Ampere Ratings
IEC 60059| Rating (A) | Typical Applications |
|---|---|
| 1.0 | R10 base value |
| 1.25 | R10 series |
| 1.6 | R10 series (common) |
| 2.0 | R10 series |
| 2.5 | R10 series |
| 3.15 | R10 series (common) |
| 4.0 | R10 series |
| 5.0 | R10 series |
| 6.3 | R10 series (common) |
| 8.0 | R10 series |
| 10 | R10 base decade |
| 12.5 | R10 series |
| 16 | R10 series (very common) |
| 20 | R10 series |
| 25 | R10 series |
| 31.5 | R10 series (common) |
| 40 | R10 series |
| 50 | R10 series |
| 63 | R10 series (very common) |
| 80 | R10 series |
| 100 | R10 base decade |
Selection Notes
- • R10 series: ×1.25 ratio (1.0, 1.25, 1.6, 2.0, 2.5, 3.15, 4.0, 5.0, 6.3, 8.0)
- • R20 series: ×1.12 ratio for finer gradation
- • Why 63A? R10 series: 6.3 × 10 = 63 (preferred over 60 or 65)
- • Why 315A? R10 series: 3.15 × 100 = 315 (preferred over 300 or 320)