This practical guide shows you how to complete a signed, QR-verified RCD / Residual Current Device Trip Time & Ramp Test Report certificate in OhmCert Module #27 and how to troubleshoot non-compliant readings on site.

1. Step-by-Step OhmCert UI Workflow

  1. Open Module #27: Navigate to RCD / Residual Current Device Trip Time & Ramp Test Report from the Dashboard.
  2. Load a 1-Click Standard Annex Preset: Open the blue Standard Annex banner at the top and click a preset (such as "30 mA Type A Socket / Final Circuit RCD (General Non-Delayed)") to populate target limits automatically.
  3. Enter Your Field Measurements: Fill in the measured inputs (RCD Time-Delay Characteristic, RCD Residual Current Waveform Type, Rated Residual Operating Current IΔn, Touch Voltage Safety Limit UL, 0.5x IΔn Non-Operating Hold Test Result, Trip Time at 1x IΔn (0 deg Half-Cycle), Trip Time at 1x IΔn (180 deg Half-Cycle), Worst-Case Trip Time at 5x IΔn (0/180 deg), Measured Sinusoidal Ramp Trip Current I_Δtrip, Measured Contact Touch Voltage Uc (at 1x IΔn)). Blank inputs stay neutral PENDING.
  4. Complete the 12-Point Checklist: Grade each item, attach photos if needed, and export the SHA-256 signed PDF certificate.

2. Worked Numerical Field Case Study

Scenario: 30 mA Type A Socket / Final Circuit RCD (General Non-Delayed) (IEC 60364-4-41 §415.1) — Standard 30 mA Type A personal protection RCD tested at 0.5x, 1x, 5x, and ramp..

  • RCD Time-Delay Characteristic: General (Non-Delayed) - Type AC / A / F / B
  • RCD Residual Current Waveform Type: Type A (AC + Pulsating DC <= 6 mA)
  • Rated Residual Operating Current IΔn: 30 mA
  • Touch Voltage Safety Limit UL: 50 V
  • 0.5x IΔn Non-Operating Hold Test Result: Held (Did Not Trip at 0.5x IΔn)
  • Trip Time at 1x IΔn (0 deg Half-Cycle): 23 ms
  • Trip Time at 1x IΔn (180 deg Half-Cycle): 27 ms
  • Worst-Case Trip Time at 5x IΔn (0/180 deg): 14 ms
  • Measured Sinusoidal Ramp Trip Current I_Δtrip: 23.5 mA
  • Measured Contact Touch Voltage Uc (at 1x IΔn): 3.8 V

3. Engineering Troubleshooting: Corrective Actions When a Reading Fails

  1. Replace any RCD that fails to trip within 300 ms at 1x IΔn (or 40 ms at 5x IΔn for 30 mA personal protection) immediately.
  2. Upgrade Type AC devices to Type A, Type F, or Type B per IEC 60364-5-53 §531.3.3 where inverter or EVSE loads are connected.
  3. Subdivide circuits with excessive standing leakage (> 0.3 x IΔn = 9 mA on a 30 mA RCD) across individual RCBOs.

→ Try This Worked Example Live in Module #27 (RCD Trip & Ramp Test)