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EOCRSSD-30DF7 is a digital motor protector manufactured by Schneider Electric (formerly Samwha, South Korea) with current range 3-30A and 110VAC control power supply. It provides triple protection against overload, phase loss and locked rotor. It is applicable for precise protection of three-phase low-power motors, capable of replacing traditional thermal relays to improve protection accuracy and fault diagnosis efficiency.
- Model Code Definition
| Code Segment | Description |
| EOCR | Electronic Over Current Relay, core product positioning |
| SSD | Solid State Digital, adopting solid-state electronic components and digital control technology |
| 30 | Current protection range: 3~30A (direct connection, no external CT required) |
| D | Digital Display, equipped with digital tube to display real-time 3-phase average current and fault status |
| F7 | Control power specification: 110VAC±15% (50/60Hz); other options: M7(220VAC), B(24VAC/DC) |
- Main Technical Specifications
| Category | Parameters | Remarks |
| Basic Info | ||
| Brand | Schneider Electric (Former Samwha Korea) | Produced in Iksan, Korea; Authorized agent in China: Shanghai Hanshi Electric |
| Product Type | Digital Overcurrent Relay / Motor Protector | Higher precision (±5%) than traditional thermal relay |
| Electrical Parameters | ||
| Rated Operating Voltage | 600V AC (UL) / 690V AC (CSA, IEC 60947-4-1) | Suitable for low-voltage motor circuits |
| Rated Impulse Withstand Voltage | 6kV | Compliant with IEC 60947-4-1 |
| Control Power | 110VAC±15%, 50/60Hz | Matched with F7 code |
| Power Consumption | ≤3W | Low power consumption for long-term operation |
| Protection Parameters | ||
| Adjustable Current Range | 3~30A continuously adjustable | Adjustment ratio: 10:1 |
| Protection Functions | 1. Overcurrent (O-Time: 0.5~10s adjustable) | Independent adjustable start delay D-Time |
| 2. Phase loss (fast protection within 3s) | ||
| 3. Locked rotor (combined D-Time+O-Time protection) | ||
| Reset Mode | Manual / Electric (optional) | Reset required after fault for restart |
| Output & Display | ||
| Output Contact | 1 NC + 1 NO (2-SPST) | Contact rating: 3A/250VAC |
| Display Mode | Digital tube display | Real-time 3-phase average current, flashing fault code indication |
| Physical & Environmental | ||
| Dimension | 45×75×110mm, standard DIN rail mounting | Compact size saves cabinet space |
| Protection Grade | IP20 (front panel) | Suitable for installation inside control cabinets |
| Operating Temperature | -20℃ ~ +60℃ | Adaptable to industrial temperature variation |
| Storage Temperature | -40℃ ~ +85℃ | Meet transportation and storage requirements |
| Certification | ||
| International Certifications | CE, UL, CSA | Comply with IEC 60947-4-1, global applicable |
| Air Freight Compliance | No built-in lithium battery, conform to UN38.3 | Shippable as general cargo without special packaging |
- Cross-brand Comparison
| Model | Current Range | Control Power | Display | Protection | Price Range | Application |
| Schneider EOCRSSD-30DF7 | 3~30A | 110VAC | Digital display | Overload / Phase loss / Locked rotor | 350~450CNY | 3-phase low-power motors with fault diagnosis demand |
| ABB CM-MSS.31P | 3~30A | 24~240VAC/DC | Indicator light | Overload / Phase loss / Locked rotor | 400~500CNY | General industrial motors, unified brand matching |
| Siemens 3RB2026-1SB0 | 2.5~32A | 24~240VAC/DC | Indicator light | Overload / Phase loss | 300~400CNY | Supporting Siemens PLC, basic protection |
| Omron K8DS-PH1 | 3~30A | 100~240VAC | Digital display | Overload / Phase loss / Locked rotor | 380~480CNY | Automated production lines, high-precision protection |
| Chint NR2-32 | 2.5~32A | No control power | No display | Overload / Phase loss | 50~80CNY | Economy application, low precision requirement |
Selection Key Points
- Display function: EOCRSSD-30DF7 supports real-time current monitoring and fault diagnosis, superior to indicator-light-only models
- Protection accuracy: Electronic protector (±5%) far exceeds thermal relay (±15%), extending motor service life
- Control power: 110VAC F7 version fits specific regional power grids, confirm on-site power supply first
- Full Series Model List
EOCR-SSD Series Classification
| Current Range | Base Model | Power Options | Complete Model Examples |
| 0.5~6A | EOCRSSD-05S | S:24~240VAC/DC | EOCRSSD-05DF7, EOCRSSD-05DM7, EOCRSSD-05DB |
| F7:110VAC | |||
| M7:220VAC | |||
| W:380~440VAC | |||
| 3~30A | EOCRSSD-30S | Same as above | EOCRSSD-30DF7, EOCRSSD-30DM7, EOCRSSD-30DW |
| 5~60A | EOCRSSD-60S | Same as above | EOCRSSD-60DF7, EOCRSSD-60DM7, EOCRSSD-60DS |
Order Code & Accessories
Standard order number: EOCRSSD-30DF7
Mounting bracket: EOCR-MNT-01 (DIN rail type)
Extension cable: EOCR-CAB-05 (5m) / EOCR-CAB-10 (10m)
Test kit: EOCR-TEST-KIT (including analog load & calibrator)
- Common Faults & Maintenance Solutions
| Fault Phenomenon | Possible Causes | Troubleshooting Steps | Solutions | Preventive Measures |
| No digital display | 1. Control power disconnected | 1. Measure terminal voltage | 1. Connect 110VAC correctly | Check power spec before installation |
| 2. Wrong wiring polarity | 2. Check wiring | 2. Adjust connection (AC non-polar) | ||
| 3. Internal fuse blown | 3. Inspect internal fuse | 3. Replace 0.5A fuse | ||
| False tripping | 1. Low current setting | 1. Confirm motor rated current | 1. Set current to 1.1 times rated value | Set parameters per motor nameplate |
| 2. Short start delay | 2. Extend D-Time | 2. D-Time = motor start time +1s | ||
| 3. Power harmonic interference | 3. Test power THD | 3. Install power filter | ||
| Failure to trip | 1. Excessively high current setting | 1. Check current setting | 1. Set current to 0.9 times rated value | Regular contact inspection, avoid overload |
| 2. Damaged output contacts | 2. Test contact continuity | 2. Replace contact module | ||
| 3. Internal circuit failure | 3. Inspect internal components | 3. Contact after-sales service | ||
| Garbled display | 1. Voltage fluctuation | 1. Test power stability | 1. Install voltage stabilizer | Keep away from inverters, ensure good grounding |
| 2. Electromagnetic interference | 2. Check grounding | 2. Optimize grounding | ||
| 3. Program error | 3. Power cycle restart | 3. Restore factory settings |
Maintenance Cycle
- Daily inspection: Check display status and alarm indicator
- Monthly maintenance: Dust cleaning, tighten wiring terminals
- Quarterly calibration: Verify protection parameter accuracy
- Annual overhaul: Inspect internal components, replace aging parts
- Application Scenarios & Cases
Applicable Scenarios
Industrial automation: CNC machine tools, conveyors, printing equipment
Water treatment: Water pumps, fans with frequent startup and variable load
HVAC: Air compressors, cooling tower fans
Building materials industry: Mixers, heavy-duty conveyors
Power system: Standby generators, small transformer protection
Non-recommended Scenarios
High voltage motors (>690V): Adopt dedicated high-voltage protectors
Explosion-proof environment: Extra explosion-proof housing required with higher cost
Ultra-low current (<0.5A): Choose EOCRSSD-05S or match external CT
Typical Cases
Case 1: Water Pump Motor Protection in Steel Plant
Problem: Frequent false tripping of old thermal relays causing unplanned shutdowns without fault identification
Solution: Install EOCRSSD-30DF7, set current 15A (motor rated 13.5A), start delay 5s
Effect: False shutdown rate reduced by 62%, fault diagnosis time shortened from 2h to 5min, annual maintenance cost saved about 80,000 CNY
Case 2: Mixer System in Pharmaceutical Factory
Problem: Motor burnout caused by mixer locked rotor leading to heavy losses
Solution: Adopt EOCRSSD-30DF7, set locked rotor protection (D-Time=3s, O-Time=1s)
Effect: Power cut within 3s once locked rotor occurs, 100% motor intact rate, avoid production stop losses
- Selection Rules
Quick Selection Rules
- Current matching: Set protection current within 0.9~1.1 times motor rated current
- Delay setting: Start delay (D-Time) = actual motor startup time + 1 second
- Power supply: Prioritize matching on-site control power to avoid extra transformer cost
- Display demand: Choose D-type for fault diagnosis, non-D-type for basic protection only
- Air Freight Compliance & Certifications
- Air Freight Regulation
No built-in lithium batteries or supercapacitors, fully compliant with UN38.3 air transport standards
Can be delivered as general goods, no MSDS or special shipping documents needed
Packaging suggestion: Anti-static bag + hard carton to prevent vibration damage
- Qualification Certificates
CE: Comply with EU LVD & EMC directives
UL: Meet US safety standards for North America market
CSA: Certified for Canadian market
IEC: Conform to international electrical standards for global use
