A mid-sized automotive parts manufacturer in Guangdong Province runs three assembly lines with more than 800 employees. The plant operates 24/7 to meet OEM delivery schedules, and its electrical system has grown piecemeal over 15 years. The facility’s maintenance team manages over 200 distribution boards, many of which feed high-energy equipment such as robotic welding machines and conveyor motors.
The company was under pressure to improve workplace safety after a minor electrical fire in a storage area caused two days of downtime. Although no one was injured, the incident triggered an insurance review and increased scrutiny from the local fire safety authority.
The plant experienced frequent nuisance tripping from conventional circuit breakers, on lines with variable-frequency drives. Maintenance staff disabled protection to keep production running, a dangerous workaround that left circuits unprotected. Meanwhile, aging wiring and loose terminal connections created intermittent arc faults, which are difficult for standard breakers to detect.
The consequences were measurable: three to four unplanned shutdowns per month, each costing an average of $12,000 in lost output and repair labor. The near-miss fire also raised insurance premiums by 8% year over year. The electrical team spent roughly 15 hours per week on troubleshooting and resetting tripped breakers, diverting time from preventive maintenance.
The company assessed several options: upgrading to higher-rated MCBs, installing residual amperage devices, and retrofitting with arc fault detection devices (AFDDs). Traditional breakers could not solve the arc-fault issue because they only react to overamperage or short circuits, not to partial-series arcs caused by damaged insulation or loose connections.
After comparing three AFDD suppliers, the factory chose the Singi Cable AFDD because it complies with IEC 62606:2013, the general requirements for arc fault detection devices, and offers a compact DIN-rail design that fits existing distribution boards without major modification. The device uses microprocessor-based analysis to distinguish dangerous arcs from normal arcing of motors or switches, reducing false tripping. The sales engineer provided clear installation guidance and local technical support, which was critical for the plant’s tight maintenance schedule.
The project took six weeks from audit to full deployment. The maintenance team worked with a Singi Cable application engineer to complete the following steps:
The most challenging step was initial false tripping on circuits with variable-frequency drives. The AFDD’s sensitivity had to be tuned to ignore inverter-generated high-frequency noise while still detecting genuine arc faults. The Singi Cable engineer suggested adding ferrite cores and improving grounding on two lines, which eliminated the problem without compromising safety.
Within four months of full operation, the factory achieved the following improvements:
The insurance premium was renegotiated downward by 5% after the facility demonstrated compliance with modern arc fault protection standards. The plant also passed its annual fire safety inspection without any violations, improving its ability to take on new contracts from global OEMs that audit supplier safety records.
“The Singi Cable AFDD paid for itself within the first year. We no longer worry the aging wiring in the older part of the plant, and the maintenance team trusts the protection instead of bypassing it,” said the plant maintenance manager.
For factories facing similar arc fault hazards, three lessons stand out:
If the project were redone, the team would have included the compressed-air system in the first phase as well, since the audit showed it had a high incidence of loose connections. That would have captured additional savings earlier.
The following standards were referenced during this project and are relevant to arc fault detection devices:
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