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Schneider EZ9C1263 Easy9 Series Overvoltage/Undervoltage Relay
Model Interpretation
| Model Component | Meaning |
| EZ9 | Easy9 Series (Schneider‘s cost-effective series for residential/commercial low-voltage terminal power distribution) |
| C | Voltage control relay (with overvoltage/undervoltage protection function) |
| 12 | Function type code (representing overvoltage/undervoltage protection + automatic reclosing function) |
| 63 | Rated current 63A |
| No suffix | 2P (1P+Ns) pole configuration, suitable for 230VAC single-phase circuits |
- Core Technical Parameters
| Parameter Category | Value | Remarks |
| Product Type | Overvoltage/undervoltage relay (with automatic reclosing) | Not a miniature circuit breaker, must be used in conjunction with MCB |
| Pole Number | 2P (1P+Ns, phase line + neutral line) | Breaks phase line and neutral line simultaneously to provide complete protection |
| Rated Current (In) | 63A | Suitable for loads below standard 63A |
| Rated Operating Voltage (Ue) | 230V AC 50Hz | Applicable to single-phase residential/commercial power supply systems |
| Overvoltage Protection Setting Value | 275V (tripping time: 3-15s) | Graded protection to prevent equipment damage caused by overvoltage of varying degrees |
| 300V (tripping time: 1-5s) | ||
| 350V (tripping time: 0.25-0.75s) | ||
| 400V (tripping time: 0.1-0.2s) | ||
| Undervoltage Protection Setting Value | 170V (tripping time: 3-15s) | Prevents abnormal operation of equipment due to low voltage |
| 150V (tripping time: 1-5s) | ||
| 130V (tripping time: 0.25-0.75s) | ||
| Reclosing Function | Automatic reclosing, maximum 3 reclosing attempts | Interval between each reclosing is about 1 minute to prevent frequent reclosing |
| Protection Characteristic | Graded time-delay protection | Avoids maloperation caused by instantaneous voltage fluctuations |
| Rated Insulation Voltage (Ui) | 440V AC | Complies with IEC 60947-4-1 standard |
| Protection Class | IP20 | Prevents finger contact with live parts, suitable for distribution box installation |
| Operating Ambient Temperature | -5掳C~+60掳C | No derating required during use |
| Installation Method | DIN rail mounting (35mm standard rail) | Compatible with other products of Easy9 series for convenient installation |
| Dimensions | Module width: 2 modules (about 36mm) | Compact design, saving distribution box space |
| Service Life | Mechanical life: 50,000 operations | Complies with IEC 60947-3 standard |
| Electrical life: 20,000 operations (at rated current of 63A) |
III. Core Functional Features
- Dual Overvoltage/Undervoltage Protection
Overvoltage Protection: Automatically disconnects the circuit when voltage exceeds 275V (±10V) to prevent electrical appliances from being damaged by overvoltage.
Undervoltage Protection: Automatically disconnects the circuit when voltage is lower than 170V (±10V) to avoid burnout of motors and other equipment due to undervoltage overload.
Graded Time Delay: Automatically adjusts tripping time according to the degree of overvoltage/undervoltage to improve protection accuracy.
- Automatic Reclosing Function
Automatically recloses after voltage returns to normal without manual intervention.
Maximum reclosing attempt limit (3 times) to prevent frequent reclosing when faults persist.
Reclosing interval is about 1 minute to ensure circuit stability before reconnection.
- Safety Design Highlights
Fault Lockout: Automatically locks in the open position after 3 failed reclosing attempts, requiring manual reset.
Test Button: Manually tests whether the protection function is normal to ensure equipment reliability.
Arc-free Design: No arc ejection during breaking, improving operational safety.
Cooperative Operation with MCB: Must be installed downstream of MCB to utilize MCB for short-circuit and overload protection.
- Installation and Application Key Points
- Installation Requirements
Installation Location: Must be installed downstream of the miniature circuit breaker (MCB) as a secondary protection device.
Wiring Method: Strictly distinguish phase line (L) and neutral line (N), with clear markings on wiring terminals.
Installation Direction: Vertically installed on 35mm standard DIN rail, with wiring available at both upper and lower ends.
Environmental Conditions: Install in a well-ventilated and dry place, avoiding humidity, dust and corrosive gases.
- Application Scenarios
| Application Field | Typical Usage |
| Residential Power Distribution | Main distribution box of households, protecting air conditioners, refrigerators, TVs and other household appliances from voltage fluctuation damage |
| Commercial Buildings | Offices, shops, hotel guest rooms, etc., protecting computers, printers and other office equipment |
| Small-scale Industry | Control circuits of single-phase equipment, protecting PLC, frequency converters and other precision electronic devices |
| Photovoltaic Systems | Front end of single-phase grid-connected inverters, protecting inverters from grid voltage fluctuations |
- Recommended Supporting Equipment
MCB Matching: It is recommended to use Schneider Easy9 series EZ9F53263 (2P 63A C-curve, breaking capacity 6kA).
Distribution Box: Easy9 series compact distribution box with IP43 protection class, suitable for rail mounting.
Wiring Terminals: Use copper lugs for connection to ensure good contact and reduce heating risk.
- Selection and Alternative Solutions
- Selection Key Points
Confirm circuit type: Only applicable to 230VAC single-phase circuits; other models should be selected for three-phase circuits.
Match load current: Rated current ≥ maximum load current; 63A is recommended for residential main protection.
Use with MCB: Must be used in conjunction with MCB and cannot be used alone as a circuit protection device.
- Alternative Model Reference
| Demand Scenario | Recommended Model | Difference Description |
| No Reclosing Required | EZ9C1163 | Only overvoltage/undervoltage protection, without automatic reclosing function |
| 40A Rated Current | EZ9C1240 | Suitable for branch circuit protection with small load current |
| Integrated Leakage Protection | EA9ZGQ263 | Integrated design of overvoltage/undervoltage + leakage protection + automatic reclosing |
| Three-phase Circuits | Select Acti9 series voltage relay | Applicable to 400VAC three-phase circuits |
- Fault Diagnosis and Maintenance
| Fault Phenomenon | Possible Causes | Troubleshooting Methods |
| Frequent Tripping | Large grid voltage fluctuations; low setting value; abnormal load | Check grid quality; adjust setting value; troubleshoot load faults |
| No Action | Wiring error; power supply failure; relay damage | Verify wiring diagram; check power supply; replace the relay |
| Reclosing Failure | Persistent faults; exceeded reclosing attempt limit | Troubleshoot circuit faults; manually reset before reconnection |
| Abnormal Heating | Loose wiring; load overload; excessively high ambient temperature | Tighten wiring; check load; improve ventilation conditions |
Summary
Schneider EZ9C1263 is an overvoltage/undervoltage relay specially designed for 230VAC single-phase circuits. Its core advantage lies in the automatic reclosing function, which can automatically restore power supply after voltage returns to normal, improving the convenience of electricity use. As a member of the Easy9 series, its compact design, DIN rail mounting and high reliability make it an ideal choice for protecting precision electronic equipment in residential and small-scale commercial buildings. It should be noted that this product is not a miniature circuit breaker and must be used in conjunction with MCB to achieve complete short-circuit, overload and voltage protection functions.
