The YDS Dual-Relay Star-Delta Timer, developed by Borna Electronics, is an effective solution for starting three-phase induction motors using the star-delta starting method. The relay automatically controls the transition from star connection to delta connection, helping reduce motor starting current and minimizing electrical and mechanical stress during startup.
The star operating time can be adjusted by the user. After the star contactor is disconnected, a fixed 50 ms transition delay is applied before energizing the delta contactor. This built-in interlocking function prevents simultaneous energization of the star and delta contactors, ensuring safe and reliable motor operation.
Features
- Adjustable star starting time from 3 to 60 seconds
- Fixed 50 ms delay between star contactor OFF and delta contactor ON
- Prevents simultaneous operation of star and delta contactors
- Simplified star-delta control wiring
- No additional interlocking protection circuit required
- Available with 110 VAC, 220 VAC, and 380 VAC supply voltages
- Two independent output relays
- Dedicated output for star contactor control
- Dedicated output for delta contactor control
- LED indicator for DELTA operating status
Technical Specifications
| Parameter | Specification |
| Supply Voltage | 220 VAC ±15% (other voltages available upon request) |
| Network Frequency | 50 Hz ±5% |
| Internal Power Consumption | 3 W |
| Timing Range | Adjustable from 3 to 60 seconds |
| Protection Degree | IP20 according to IEC 60529 |
| Operating Temperature | -20°C to +60°C |
| Relative Humidity | 15% to 85% |
| Mounting Method | DIN Rail according to IEC 60715 |
| Output Relays | Two independent C/O (SPDT) relays, 6 A |
Applications
- Three-phase induction motor starting
- Star-delta motor starter panels
- Industrial motor control systems
- Pumps and compressors
- Fans and blowers
- Applications requiring reduced motor starting current