Molded Case Circuit Breaker - MCCB

DZ20Y-100-3300 Molded-Case-Circuit-Breake MCCB

DZ20Y MCCB Molded-Case-Circuit-Breaker 100A-1600A

DZ20Y series molded case circuit breakers (MCCB) are industrial-grade protection devices designed for AC 50Hz power distribution systems with rated operational voltage up to 380V (Ui=660V) and rated current ranging from 100A to 1250A. They provide reliable protection against overload, short-circuit, and under-voltage for distribution lines and power equipment, and can also be used for infrequent circuit switching and motor starting under normal operating conditions.

Compared with DZ15 series (small current, economical type for civil use), DZ20Y features higher short-circuit breaking capacity (Icu=30~40kA), wider current range, support for 3P/4P pole configuration, and compatibility with various accessories (auxiliary contacts, alarm contacts, undervoltage release, etc.). The series complies with GB/T 14048.2, JB/T 8589 and IEC 60947-2 standards, with optional white cover or transparent cover versions to meet different application requirements.

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2. Core Advantages

• Wide rated current range: 100A ~ 1250A (divided into 100/225/400/630/1250 frame sizes)

• High short-circuit breaking capacity: Icu=30~40kA, suitable for industrial high-current scenarios

• Support 3P/4P pole configuration, compatible with three-phase four-wire power supply system

• Optional transparent cover (visual internal structure) or white cover (better dustproof performance)

• Complete accessory compatibility: auxiliary contact, alarm contact, undervoltage release, electric operating mechanism

• Long mechanical/electrical life: mechanical life up to 10,000 times, electrical life up to 2,000 times

• Wide operating temperature range: -5℃ ~ +40℃, suitable for various industrial environments

3. Application Scenarios

  • Main incoming/outgoing lines of industrial plant power distribution cabinets
  • Protection of medium and large power motor circuits (≤630A)
  • Power distribution systems of high-rise buildings, commercial complexes
  • Power supply circuits of large-scale industrial equipment and production lines
  • Three-phase four-wire power distribution systems requiring 4P protection
  • Backup power supply systems and generator sets

4. Model Interpretation

Example: DZ20Y-400/3310

• DZ: Molded case circuit breaker

• 20: Design serial number

• Y: General type (standard breaking capacity)

• 400: Frame rated current (400A)

• 3: 3 poles

• 3: Thermal-magnetic release

• 1: With undervoltage release

• 0: Without auxiliary contact

Common suffix combinations:

• 3300: 3 poles + thermal-magnetic release + no accessories

• 3310: 3 poles + thermal-magnetic release + undervoltage release

• 4300: 4 poles + thermal-magnetic release + no accessories

Main Technical Parameters

5. Technical Parameters

Parameter Category Parameter Item DZ20Y-100 DZ20Y-225 DZ20Y-400 DZ20Y-630 DZ20Y-1250 Unit
Basic Electrical Parameters Rated Operational Voltage (Ue) 380 380 380 380 380 V
Rated Insulation Voltage (Ui) 660 660 660 660 660 V
Rated Impulse Withstand Voltage (Uimp) 6 6 6 6 6 kV
Rated Frequency (f) 50 50 50 50 50 Hz
Rated Current (In) 16~100 100~225 250~400 400~630 630~1250 A
Pole Number 3P/4P 3P/4P 3P/4P 3P/4P 3P/4P –
Short-circuit Breaking Capacity Rated Ultimate Short-circuit Breaking Capacity (Icu) 30 30 35 35 40 kA
Rated Service Short-circuit Breaking Capacity (Ics) 15 15 17.5 17.5 20 kA
Peak Short-circuit Withstand Current (Icw) 63 63 80 80 100 kA
Tripping Characteristics Overload Tripping (1.05In) No trip in 2h No trip in 2h No trip in 2h No trip in 2h No trip in 2h –
Overload Tripping (1.30In) Trip in <2h Trip in <2h Trip in <2h Trip in <2h Trip in <2h –
Short-circuit Instantaneous Tripping (10In) Trip <0.2s Trip <0.2s Trip <0.2s Trip <0.2s Trip <0.2s –
Undervoltage Tripping Voltage Range 70%~35% Ue 70%~35% Ue 70%~35% Ue 70%~35% Ue 70%~35% Ue –
Mechanical Characteristics Mechanical Life 10000 10000 8000 8000 6000 Times
Electrical Life 2000 2000 1500 1500 1000 Times
Operating Temperature Range -5℃ ~ +40℃ ℃
Protection Grade IP Rating (Case) IP30 –
Standards Compliance Applicable Standards GB/T 14048.2, JB/T 8589, IEC 60947-2 –

Installation Instructions and Selection Guide

7. Installation Instructions

• DZ20Y series supports front connection and rear connection two installation methods, please select according to the actual cabinet design.

• For models with rated current ≥400A, copper bar connection is recommended to ensure good electrical conductivity and heat dissipation.

• The installation hole size must match the Φd parameter in the dimension table to avoid installation instability.

• Ensure the ambient temperature is within -5℃ ~ +40℃ during installation, and avoid direct sunlight or high humidity environments.

• After installation, check the flexibility of the operating handle and the reliability of the wiring before power-on.

8. Selection Guide

Frame Size Selection:

1. DZ20Y-100: Suitable for industrial auxiliary circuits with rated current ≤100A (e.g., lighting, small power distribution)

2. DZ20Y-225: Suitable for motor protection or distribution circuits with rated current 100~225A

3. DZ20Y-400/630: Suitable for main incoming/outgoing lines of distribution cabinets with rated current 250~630A

4. DZ20Y-1250: Suitable for total incoming lines of high-power distribution cabinets with rated current 630~1250A

Accessory Selection:

• Undervoltage release (suffix 3310): Required for circuits that need undervoltage protection

• Auxiliary contact: Required for remote monitoring of breaker status

• Electric operating mechanism: Required for remote control of breaker switching

Install Dimension

DZ20y pannel front wiring dimension
DZ20Y-backpanel wiring dimension

6. Outline & Installation Dimensions

Note: The following dimensions are for front connection type. For rear connection dimensions, please contact our technical support.

Figure 1: Outline & Installation Dimensions (Front Connection)

DZ20Y Front Connection Dimensions
Model W L H W1 L1 L2 H1 H2 H3 A B Φd Unit
DZ20Y-100 105 165 86 70 — 215 103 26 26 35 126 5 mm
DZ20Y-225 108 256 105 70 326 402 142 20 20 35 196.5 4.5 mm
DZ20Y-400 155 276 116 102 391 — 150 27 27 51 240 7 mm
DZ20Y-630 210 268 108 140 367 — 147 22 22 70 200 7 mm
DZ20Y-1250 212 393 142 140 559 — 216 31 31 70 360 10 mm