Troubleshooting intermittent RCD Tripping with Hioki’s AC Leakage Clamp Meter CM4003

A Residual Current Device (RCD) is the generic term for safety devices that automatically switches electricity off when a current leakage occurs. These devices monitors the Residual current levels compared with the rated nominal tripping current to disconnect the supply of power. By doing so, it protects users against any electrical hazards such as accidental electrocution, equipment malfunctions & fire hazards. Due to the nature of the RCD, when a leakage current has exceeded the designated RCD’s threshold value, intermittent RCD tripping will occur more frequently. To combat this issue, a clamp meter can help detect & prevent these potential issues in the circuit. Check the leakage current measurement by clamping the leakage current sensor clamp to the round-trip wiring or ground conductors.

Hioki’s AC Leakage Clamp Meter CM4003 allows users to measure a range of currents, from minute leakage current to load current. Measurement of leakage currents can be measured with a single or multiple wires. To measure load currents, only 1 wire should be clamped as special wave forms such as the secondary side of the inverter may not be measured if 2 or more wires are in a bundle.

In normal circumstances, intermittent RCD tripping is unpredictable. Many find it time-consuming to trouble shoot & would choose to tolerate instead of spending an inadequate amount of time trying to identify & locate the issue.

Unlike most clamp meters, the CM4003 has a configurable threshold value set by the user for event recording triggers, measure leakage values as well as record intermittent tripping events on your RCDs. A blinking red backlight will appear when the maximum value has reached the set threshold value.

Users can use this function to test where the leakage occurs. Configurations can be made, viewed, monitored, recorded& a measurement report created with Bluetooth connection to the GENNECT Cross software on a tablet or mobile device at a range of 10m with a clear line of sight. After the set up is complete, there is no need to maintain a connection with the tablet or mobile device while the recording is ongoing. Data collected by the clamp meter can be imported through the GENNECT Cross application, which indicates the maximum leakage values & what time the each trip event starts & stops. From the data provided, users can easily identify the location of leakage causing the trip & take calculated steps to rectify the issue.

By repeating the above steps & collecting the data from different suspected locations of the leakage, users can determine trip locations & leakage values efficiently.

On standalone mode, the CM4003 can log up to 999 events. For an extended duration of continuous measurement recordings, the clamp meter has a record time of up to 30 days (limited by battery life). Only the CM4003 AC Leakage Clamp Meter can be used withal  AC Adapter Z1013 for external power supply & Hioki’s Memory Hi Cored to check & record output functions visually. Best used when investigating intermittent or occasional earth leakage, users are able to check records for time &variation of the leakage current value.

Key features of Hioki’s AC Leakage Clamp Meter includes:

• High permeability magnetic materials, designed based on the principle of electromagnetic induction, allowing easy flow of the current. The effects of external electromagnetic noise are also minimized to enable the measurement with high reproducibility.
• A large jaw of a 40mm circumference that provides uniform measurement sensitivity regardless of the conductor’s position inside the jaws, used for both single & bundled wires; Measurement of AC inrush current value, which will be on hold automatically if the measurements do not fluctuate beyond its variation range. These measurements will be held until the auto-hold conditions are satisfied again
• External magnetic field resistance of 4mA or less when in an external magnetic field of 400A/m with 50 Hz/60 Hz
• Comparator function with warning signals such as a buzzer sounds & warning backlights will light up; indicating measured values have exceeded the threshold which can be adjusted accordingly. The buzzer can be disabled according to the user’s preferences.
  

For more detailed information on usage instructions &specifications, Hioki’s website provides a CM4003 AC Leakage Clamp Meter application manual in a downloadable PDF form.