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Y501/Y502 Technical Manual
| Y501 (1P) | Y502 (2P) |
|---|---|
Table of Contents
1. Overview
This manual covers Modbus-RTU commands for Y501/Y502 smart circuit breakers.
| Model | Poles | Description |
|---|---|---|
| Y501 | 1P | Single-pole smart circuit breaker |
| Y502 | 2P | Double-pole smart circuit breaker |
Frame Format: [Slave ID][Function][Data][CRC Lo][CRC Hi]
All examples use slave address 0x01. Replace with your device address.
2. Default Settings
| Parameter | Default |
|---|---|
| Slave Address | 1 |
| Baud Rate | 9600 bps |
| Data Bits | 8 |
| Parity | None |
| Stop Bits | 1 |
| CRC | CRC16, low byte first |
3. Modbus Register Map
3.1 Coil Registers — Function 0x01/0x05
| Address | Function | Access |
|---|---|---|
| 0x0001 | Close/Open Control | R/W |
Write value: 0x0000 = open (OFF), 0xFF00 = close (ON).
3.2 Holding Registers — Function 0x03/0x06
| Address | Function | Access |
|---|---|---|
| 0x000D | Close/Open Control | R/W |
Write value: 0x0000 = open, 0xFF00 = close.
3.3 Input Registers — Function 0x04 (Metering Version)
| Address | Parameter | Unit | Description |
|---|---|---|---|
| 0x0004 | Frequency | Hz | Grid frequency |
| 0x0005 | Leakage Value | mA | Residual current (RCBO version) |
| 0x0006 | Temperature N | °C | Board temperature (subtract 40) |
| 0x0007 | Temperature A | °C | Phase A temperature (subtract 40) |
| 0x0008 | Voltage A | V | Phase A voltage |
| 0x0009 | Current A | A | Phase A current |
| 0x000A | Power Factor A | - | Phase A power factor |
| 0x000B | Active Power A | W | Phase A active power |
| 0x000C | Reactive Power A | var | Phase A reactive power |
| 0x000D | Apparent Power A | VA | Phase A apparent power |
| 0x000E–0x000F | Active Energy | kWh | Cumulative energy (32-bit) |
Temperature Conversion: Subtract 40 from the reading to get actual temperature (°C).
4. Command Examples
4.1 Close/Open Control
Close (Turn ON)
| Method | Command (hex) |
|---|---|
| Write Coil | 01 05 00 01 FF 00 DD FA |
| Write Holding Register | 01 06 00 0D FF 00 59 F9 |
Open (Turn OFF)
| Method | Command (hex) |
|---|---|
| Write Coil | 01 05 00 01 00 00 9C 0A |
| Write Holding Register | 01 06 00 0D 00 00 18 09 |
4.2 Broadcast Control
Broadcast commands use address 0x00. All devices respond simultaneously with no reply.
| Operation | Command (hex) |
|---|---|
| Broadcast Close | 00 05 00 01 FF 00 DC 2B |
| Broadcast Open | 00 05 00 01 00 00 9D DB |
4.3 Read Voltage
Read Phase A Voltage
Request: 01 04 00 08 00 01 B0 08
Response: 01 04 02 XX XX [CRC]XX XX = Voltage value (unit: V)
4.4 Read Current
Read Phase A Current
Request: 01 04 00 09 00 01 E1 C8
Response: 01 04 02 XX XX [CRC]XX XX = Current value (unit: A)
4.5 Read Power
| Parameter | Command (hex) |
|---|---|
| Active Power A | 01 04 00 0B 00 01 40 08 |
| Reactive Power A | 01 04 00 0C 00 01 F1 C9 |
| Apparent Power A | 01 04 00 0D 00 01 A0 09 |
4.6 Read Power Factor
Request: 01 04 00 0A 00 01 11 C8
Response: 01 04 02 XX XX [CRC]4.7 Read Energy
Read Cumulative Active Energy (32-bit)
Request: 01 04 00 0E 00 02 10 08
Response: 01 04 04 XX XX XX XX [CRC]XX XX XX XX = Cumulative energy value (unit: kWh)
4.8 Read Temperature
| Parameter | Command (hex) | Description |
|---|---|---|
| Temperature A | 01 04 00 07 00 01 80 0B | Phase A temperature |
| Temperature N | 01 04 00 06 00 01 D1 CB | Board temperature |
Subtract 40 from the reading to get actual temperature (°C).
4.9 Read Frequency
Request: 01 04 00 04 00 01 70 0B
Response: 01 04 02 XX XX [CRC]XX XX = Frequency value (unit: Hz)
4.10 Read Leakage Value
Request: 01 04 00 05 00 01 21 CB
Response: 01 04 02 XX XX [CRC]XX XX = Leakage current value (unit: mA)
4.11 Quick Reference Table
| Operation | Command (hex) |
|---|---|
| Close | 01 05 00 01 FF 00 DD FA |
| Open | 01 05 00 01 00 00 9C 0A |
| Broadcast Close | 00 05 00 01 FF 00 DC 2B |
| Broadcast Open | 00 05 00 01 00 00 9D DB |
| Read Voltage A | 01 04 00 08 00 01 B0 08 |
| Read Current A | 01 04 00 09 00 01 E1 C8 |
| Read Active Power A | 01 04 00 0B 00 01 40 08 |
| Read Power Factor A | 01 04 00 0A 00 01 11 C8 |
| Read Energy | 01 04 00 0E 00 02 10 08 |
| Read Temperature A | 01 04 00 07 00 01 80 0B |
| Read Frequency | 01 04 00 04 00 01 70 0B |
| Read Leakage | 01 04 00 05 00 01 21 CB |
5. Configuration
5.1 Change Slave Address
Write to the address configuration register (refer to product label for specific register address).
Power cycle required after change.
5.2 Change Baud Rate
Supported baud rates: 600, 1200, 2400, 4800, 9600, 19200, 38400, 57600, 115200, 230400 bps
Power cycle required after change.
5.3 Interlock Status
- Locked: Close commands are ignored; breaker remains open
- Unlocked: Normal closing operation allowed
6. Troubleshooting
| Symptom | Cause | Solution |
|---|---|---|
| No response | Wrong address or baud rate | Verify settings; try broadcast address 0 |
| CRC error | Wiring issue or noise | Check RS485 A/B polarity; add termination |
| Close fails | Interlock active | Check interlock status; unlock before closing |
| Abnormal readings | Non-metering version | Confirm product version supports metering |
| Leakage reads 0 | Non-RCBO version | Confirm product version supports leakage detection |
LED Indicators
| LED | State | Meaning |
|---|---|---|
| Power | Steady | Power OK |
| Status | Steady | Closed (ON) |
| Status | Off | Open (OFF) |
| Fault | Blink | Protection tripped or fault |
- Manufacturer: Hunan Yanji Tech Co.,Ltd
- Email: hi@yengear.com
- Website: www.yengear.com