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This is a Schneider EZD series 400A frame size, 3-pole, 250A rated current, 36kA breaking capacity molded case circuit breaker. Its standard order number is EZD400E3250K. It is applied to overload and short-circuit protection in secondary power distribution systems, featuring cost performance and installation flexibility.
- Model Segment Definition
| Model Segment | Meaning | Description |
| EZD | Product Series | Schneider EasyPact EZD molded case circuit breaker series, designed for secondary power distribution, civil buildings and electromechanical markets |
| 400 | Frame Current | 400A frame size, maximum rated current up to 400A |
| E | Breaking Capacity Class | Class E, 36kA @ 400V AC, suitable for general industrial and civil building power distribution |
| 3P | Pole Number | 3-pole, three-phase three-wire system |
| 250A | Rated Current | Thermal-magnetic trip unit rated current 250A with fixed protection setting values |
| K | Mounting Type | Fixed type / front connection (standard); PK means plug-in type |
- Core Specification Parameter Table
| Parameter Category | Detailed Specification | Remarks |
| Basic Parameters | ||
| Brand & Model | Schneider EZD400E3250K | Standard order number |
| Rated Voltage | 400V AC (Max. 690V AC) | 50/60Hz |
| Rated Insulation Voltage | 1000V AC | Compliant with IEC 60947-2 |
| Rated Current (In) | 250A | Thermal-magnetic trip TM250D |
| Pole Number | 3P | Three-phase three-wire |
| Breaking Capacity (Icu) | 36kA @ 400V AC | Class E breaking capacity |
| Protection Characteristics | ||
| Trip Unit Type | Thermal-Magnetic (TMD) | Long time delay for overload + instantaneous short-circuit protection |
| Overload Protection | 1.05In: No tripping continuously | Compliant with IEC 60947-2 |
| 1.30In: Tripping within ≤1 hour | ||
| 6.00In: Tripping within ≤2 seconds | ||
| Short-circuit Protection | Instant trip at ≥10In | Protect lines and equipment from overload and short-circuit damage |
| Mechanical & Installation Parameters | ||
| Mounting Type | Fixed (Standard) / Plug-in optional | Upper/lower incoming line interchangeable without derating |
| Wiring Method | Front wiring (Standard) | Rear wiring and plug-in wiring optional |
| Operation Mode | Manual operation (Handle) | Ergonomic design, labor-saving operation |
| Overall Dimension (W×H×D) | 140×255×110 mm | Standard dimension for 400A frame |
| Weight | Approx. 4.5 kg | |
| Mounting Position | Vertical / Horizontal / Side / Rear | Performance unaffected by mounting position |
| Environmental Parameters | ||
| Operating Temperature | -5℃ ~ +40℃ | Derate above 40℃ |
| Storage Temperature | -25℃ ~ +70℃ | |
| Protection Degree | IP30 (Body only) | IP40 with protective cover |
| Certification | ||
| Standard Compliance | IEC 60947-2, GB 14048.2 | 3C Certificate No.: 2020980307… |
- Accessory List (Compatible with EZD400 Series)
| Accessory Type | Model / Order No. | Function Description |
| Auxiliary Contact | EZ4OF101 (Single Auxiliary) | Indicate breaker ON/OFF status (OF), 1NO/1NC or 2NO/2NC |
| EZ4OF201 (Dual Auxiliary) | ||
| Alarm Contact | EZ4SD101 (Single Alarm) | Indicate breaker tripping status (SD), including fault and non-fault tripping |
| EZ4SD201 (Dual Alarm) | ||
| Shunt Trip | EZ4SHT200ACDCZ (AC220V) | Remote trip control, fire emergency trip application |
| EZ4SHT400ACZ (AC380V) | ||
| EZ4SHT048ACDCZ (DC24V) | ||
| Undervoltage Release | EZ4MN200ACZ (AC220V) | Automatic trip when voltage below set value, protect equipment from over/undervoltage damage |
| EZ4MN400ACZ (AC380V) | ||
| Extended Rotary Handle | EZ4H100 | Convenient door operation, suitable for distribution cabinet installation |
| Interphase Barrier | EZ4SP400 | Enhance interphase insulation and safety |
| Busbar | Dedicated busbar system | Suitable for multi-circuit outgoing lines, easy installation and neat layout |
| Plug-in Base | EZ4B400 | Adapt to plug-in mounting for easy maintenance and replacement |
- Alternative & Cross-Brand Comparison
4.1 Schneider Internal Series Replacement
| Series | Model | Breaking Capacity | Trip Type | Price Range | Application Scenario |
| EZD | EZD400E3250K | 36kA | Thermal-Magnetic | Medium-Low | General power distribution, cost priority |
| CVS | CVS400N3250 | 50kA | Thermal-Magnetic / Electronic | Medium | Industrial distribution, higher breaking capacity required |
| NSX | NSX400N3250 | 50kA / 70kA | Electronic (Micrologic) | High | High-end distribution, precise protection and communication required |
4.2 Cross-Brand Competitor Comparison
| Brand | Model | Frame / Rated Current | Breaking Capacity | Price Ratio | Features |
| Chint | NXM-400S/3300 250A | 400A / 250A | 36kA | About 60% of EZD | Domestic alternative, high cost performance |
| ABB | Tmax T4N250 | 400A / 250A | 50kA | About 120% of EZD | Strong breaking capacity, stable performance |
| Siemens | 3VT400N250 | 400A / 250A | 36kA | About 110% of EZD | Compatible with Siemens system, complete communication functions |
| Changshu Switch | CM3-400M/3300 250A | 400A / 250A | 36kA | About 70% of EZD | High-quality domestic brand, good compatibility |
- Selection Key Points & Alternative Solutions
5.1 Core Selection Guidelines
Load Type Matching
Distribution Protection: EZD400E series (thermal-magnetic), suitable for lighting, socket and non-motor loads
Motor Protection: Recommend EZD400M series (motor protection type with higher short-circuit trip multiple)
Residual Current Protection: Adopt VigiEZD400E series with integrated residual current protection
Breaking Capacity Selection
36kA (Class E): General industrial & civil buildings with low short-circuit current
50kA (Class M): Industrial environments with high short-circuit current, such as near inverters and large motors
Calculation Rule: Select proper breaking capacity based on system short-circuit current calculation
Mounting Type Decision
Fixed Type: Low cost, for circuits without frequent replacement
Plug-in Type: Easy maintenance, for important circuits requiring quick replacement (data center, hospital)
5.2 Recommended Alternative Solutions
| Scenario | Recommended Solution | Advantages |
| Budget Limited, General Distribution | Chint NXM-400S/3300 250A | Low price, meets basic performance requirements |
| High Breaking Capacity Required (50kA) | Schneider CVS400N3250 | Same-brand upgrade, installation dimension compatible, higher breaking capacity |
| Precise Protection & Communication Needed | Schneider NSX400N3250 + Micrologic 2.3 | Electronic trip with adjustable parameters, support Modbus communication |
| Residual Current Protection Needed | VigiEZD400E3250K | Integrated residual current protection, save space without extra module |
| Remote Control Needed | EZD400E3250K + Shunt Trip + Auxiliary Contact | Realize remote tripping and status monitoring, fit intelligent distribution system |
- Key Operation Precautions
- Derating Application: Derate rated current by 1% per 1℃ above 40℃; derate by 0.5% per 100m altitude over 1000m.
- Wiring Specification: Follow top-in bottom-out rule; fasten terminals to avoid overheating. 3P for three-phase three-wire; select 4P if neutral protection is needed.
- Accessory Installation: Auxiliary/alarm contacts, shunt/undervoltage releases can be field-installed; cut off power before installation for safety.
- Maintenance Cycle: Inspect every 6 months including appearance, mechanism flexibility and terminal tightness.
- Fault Handling: After tripping, identify cause (overload/short-circuit), eliminate fault then close again.
Complete Model List of Schneider EZD Series Circuit Breakers
Overview: The EZD series covers 5 frame sizes (100A/160A/250A/400A/630A), 3 breaking classes (E=25kA, N=36kA, M=50kA), 2 pole types (3P/4P), 2 trip types (TMD thermal-magnetic / ETU electronic; electronic only for 630A frame), 2 mounting types (Fixed N / Plug-in PK), plus residual current type (VigiEZD) and motor protection type (MA) variants.
- Model Naming Rule (Essential)
| Model Segment | Meaning | Optional Value | Description |
| EZD | Product Series | EZD | EasyPact EZD molded case circuit breaker series |
| 100/160/250/400/630 | Frame Current | 100/160/250/400/630 | Maximum rated current capacity |
| E/N/M | Breaking Capacity | E(25kA), N(36kA), M(50kA) | Ultimate breaking capacity @400V AC |
| 3-4 | Pole Number | 3(3P), 4(4P) | 3P=3-phase 3-wire; 4P=3-phase 4-wire |
| 0XX/XX0 | Rated Current | 15~630A | Rated current of thermal-magnetic trip unit |
| N/PK | Mounting Type | N(Fixed), PK(Plug-in) | Fixed as standard; PK for plug-in |
| MA | Application Type | MA(Motor Protection) | Non-MA for distribution protection |
| EL/ELA | Residual Current | EL(30mA), ELA(300mA) | Exclusive for VigiEZD series |
- Complete Model List by Frame Size
2.1 EZD100 Frame (Max. 100A)
2.2 EZD160 Frame (Max. 160A)
2.3 EZD250 Frame (Max. 250A)
2.4 EZD400 Frame (Max. 400A)
2.5 EZD630 Frame (Max. 630A, with Electronic Trip)
- Residual Current Protected Type (VigiEZD Series)
- Key Selection Instructions
- Common Model Quick Reference (Distribution Protection)
- Accessory Compatibility Guide
