DC Charging Pile Enclosure Electrification Fault Inspection

Felix Spark
06/23/2025

 
1. Fault Cases
Case 1 (July 16, 2024)
A district manager got a report of a charging pile outage at a square, affecting users and appliances. I, with O&M staff, found the pile was dead but charged EVs normally—yet the neutral wire/cabinet was live.
Inspection steps:
  • Relays, contactors, AC contactors checked → switching power supply had no output.
  • Inverter, fuse, AC power tested → live current detected.
  • Internal check: AC power and modules normal; secondary wiring intact.
  • Cooling fan test: Fan ran but was live. Replacing a faulty fan (damaged coil, leakage) restored full function (8.5kW load, 4 - hour test).

Case 2 (August 5, 2024)
A village user reported a dead display/non - charging pile. Local O&M restarted it unsuccessfully, so I called for support.
Company O&M found:
  • Abnormal three - phase voltage (L1 - N: 0V; L2/L3 - N: 360V; L1 - L3: 360V) → suspected phase fault.
  • Auxiliary switch: stable components but unstable voltage. Reconnection/test still left neutral/ground live. Pole - climbing adjustments and equipment replacement failed.
Via coordination and villagers’ info, we learned the former farmland’s underground cables were damaged (likely from poor construction/stone rolling). Replacing 30+ meters of 35mm² cable fixed voltages/electronics. The fault traced to the transformer - to - pile cable; replacing the main cable restored normalcy.
2. Fault Analysis
  • Case 1: Cooling fan insulation failure (leakage). Fan issues (non - rotation, noise) stem from inherent quality defects.
  • Case 2: Non - standard construction (no proper piping, no “buried cable” mark). The civil team failed to contact O&M or report post - work, causing the fault.
3. Lessons & Tips
For front - line workers, regular checks, careful observation, and timely defect fixes are key (these faults had early signs but worsened due to neglect). Root - cause analysis needs on - site context/construction history.
Suggestions:
  • Connect auxiliary power from the main switch output; add residual current - protected breakers for hierarchical control. Build a platform for fault monitoring.
  • Construction: Follow drawings strictly. Design inspection interfaces; use protected switches. Manage processes and pre - commissioning checks.
  • Regular O&M patrols. Clarify team roles; ban excavator work above pile cables.
  • Manufacturers: Fast after - sales response. Do annual preventive tests; enforce accountability for faults.
Felix Spark

Hey there! I'm an electrical engineer specializing in Failure and Maintenance. I've dedicated my career to ensuring the seamless operation of electrical systems. I excel at diagnosing complex electrical failures, from malfunctioning industrial motors to glitchy power distribution networks. Using state - of - the - art diagnostic tools and my in - depth knowledge, I pinpoint issues quickly. On this platform, I'm eager to share my insights, exchange ideas, and collaborate with fellow experts. Let's work together to enhance the reliability of electrical setups.

Vibration Testing and Fault Research of High - Voltage Shunt Reactors
Vibration Testing and Fault Research of High - Voltage Shunt Reactors
1 Vibration Monitoring and Fault Diagnosis Technology for High - Voltage Shunt Reactors1.1 Measuring Point Layout StrategyVibration characteristic parameters (frequency, power, energy) of high - voltage shunt reactors are fully recorded in operation logs. For vibration analysis, focus on resolving the complexity of electric field distribution at winding ends. Quantitatively evaluate field - strength distribution under operating/lightning overvoltage and voltage gradient characteristics of longit
Felix Spark
07/24/2025
Research on Online Diagnosis of Secondary Circuit Faults of Electronic Current Transformers
Research on Online Diagnosis of Secondary Circuit Faults of Electronic Current Transformers
1 Principle and Role of Electronic Current Transformers1.1 Working Principle of ECTAn Electronic Current Transformer (ECT) is a key device for managing safe power system operations, converting large currents into manageable small-current signals for measurement and control. Unlike traditional transformers (relying on direct magnetic field interaction between primary and secondary windings), ECTs use sensors (e.g., Hall effect sensors) to detect magnetic field changes from the primary winding. Th
Felix Spark
07/22/2025
What are the fault diagnosis and handling technologies for 35kV combined transformers?
What are the fault diagnosis and handling technologies for 35kV combined transformers?
For fault diagnosis and handling of 35kV combined transformers, the following technical means can be adopted:Insulation Fault DiagnosisUse equipment such as high-voltage test transformers, power frequency withstand voltage testers, and partial discharge detection systems to conduct a comprehensive assessment of the insulation performance of combined transformers. When the insulation resistance is found to be lower than 1000MΩ or the dielectric loss factor tanδ exceeds 0.5%, an applic
Felix Spark
07/21/2025
What are the common faults of low-voltage voltage transformers?
What are the common faults of low-voltage voltage transformers?
Open - Circuit Fault on the Secondary SideOpen - circuit in the secondary side is a typical fault of low - voltage voltage transformers, showing abnormal voltmeter readings (zero/fluctuation), faulty power meters, buzzing noises, and core overheating. When open - circuited, the secondary voltage spikes (no secondary current to balance the primary EMF), causing core saturation, flux distortion, and potential overheating/damage.Causes include loose terminals, poor contact, or human error. In low
Felix Spark
07/18/2025
Inquiry
Download
IEE-Business is dedicated to serving the personnel in the global power industry.
Join IEE-Business, not only can you discover power equipment and power knowledge, but also canhnd like - minded friends!