Part No.: 9705256026 (Filter PCB)
Purpose: To verify correct current detection and signal transmission from the Current Transformer (CT) to the Controller PCB through the Filter PCB.
Check Point 1: Connector Inspection
Verify that connectors CN202 (on Filter PCB) and CN11 (on Controller PCB) are securely connected.
Ensure there is no loose, corroded, or damaged pin at either connector.
Inspect the wiring harness between CN202 and CN11 for continuity and proper color coding (Red → Red).
Check Point 2: CT Resistance Verification
Measure the terminal resistance between CN11 (Controller PCB) and CN202 (Filter PCB).
Expected Resistance: Approximately 110 Ω
If the resistance is significantly higher or lower, the CT or Filter PCB is defective.
Action: Replace the Filter PCB if readings are out of specification.
Check Point 3: Voltage Output (CT Detection Current Reference Values)
Measure the voltage across CN11 while the system is operating to verify proper current detection.
Reference values are as follows:
| Voltage (mV) | Detection Current (A) |
|---|---|
| 400 | 5.6 |
| 561 | 6.9 |
| 737 | 8.4 |
| 948 | 10.0 |
| 1187 | 12.0 |
| 1525 | 14.7 |
| 1721 | 16.2 |
| 1971 | 18.2 |
| 2231 | 20.2 |
| 2495 | 22.3 |
| 2720 | 24.0 |
| 3001 | 26.1 |
| 3246 | 28.0 |
⚙ Note: These values are reference readings.
If voltage output does not correspond proportionally to current, the CT or Filter PCB may be faulty.
Always measure under stable operating conditions for accuracy.
Summary Table
| Check Point | Test Item | Expected Value | Action if Abnormal |
|---|---|---|---|
| 1 | CN202/CN11 Connection | Secure, no corrosion | Reconnect or repair |
| 2 | CT Resistance | ~110 Ω | Replace Filter PCB |
| 3 | CT Output Voltage | Matches current (see chart) | Replace Filter PCB or CT |
