Device Type
MCB≤125A

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
1Lighting circuits, very low load
2Control circuits, low power
4Lighting, small appliances
6Lighting circuits (common)
10Lighting, general purpose (common)
13UK standard for socket outlets
16Socket outlets, small motors (very common)
20Air conditioners, water heaters
25Large AC units, cooktops
32Electric showers, ovens (common)
40Main feeders, large loads
50Main distribution, EV charging
63Main breaker, sub-panels
80Industrial, large feeders
100Main service entrance
125Maximum 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
MCCB≤630A

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
10Small motors, branch circuits
15Motor loads
16Standard branch
20Motor protection
25Feeder circuits
30Standard industrial
32Motor feeders
40Distribution feeders
50Large motors
60Industrial feeders
63Standard MCCB size
80Main feeders
100Distribution mains (common)
125Panel mains
150Large distribution
160Standard industrial
200Main distribution (common)
225Large feeders
250Service entrance
300Industrial mains
315Standard rating
350Large industrial
400Main distribution (common)
500High capacity
630Maximum 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
NHSize 1-4≤630A

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
2Size 00, control circuits
4Size 00, small loads
6Size 00, lighting
10Size 00/0, general purpose
16Size 0, motors
20Size 0, feeders
25Size 0, distribution
32Size 0/1, motors
35Size 1, standard
40Size 1, common
50Size 1, feeders
63Size 1, distribution
80Size 1/2, motors
100Size 2, common
125Size 2, distribution
160Size 2, main feeders
200Size 2/3, industrial
224Size 3, standard
250Size 3, common
315Size 3, distribution
355Size 3, large
400Size 3/4, main
500Size 4, high capacity
630Size 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
R10/R20 Series

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
1.0R10 base value
1.25R10 series
1.6R10 series (common)
2.0R10 series
2.5R10 series
3.15R10 series (common)
4.0R10 series
5.0R10 series
6.3R10 series (common)
8.0R10 series
10R10 base decade
12.5R10 series
16R10 series (very common)
20R10 series
25R10 series
31.5R10 series (common)
40R10 series
50R10 series
63R10 series (very common)
80R10 series
100R10 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)