What is Pen Fault Detection and Why is it Needed?

What is Pen Fault Detection and Why is it Needed?

Understanding PEN Fault Protection

In the realm of electric vehicle (EV) charging in the UK, safety is paramount. This is where PEN fault protection comes into play, a critical feature integrated into EV chargers, particularly in the UK. Complying with the BS 7671:2018 Amendment 1:2020 clause 722.411.4.1 (iv), this feature ensures protection against neutral faults in outdoor charging setups.

It’s worth noting that all TeltoCharge EV chargers sold at LinITX.com all come with integrated Pen Fault detection and comply with UK standards and laws relating to EV charging.

How It Works

PEN fault protection activates if the charger detects voltage fluctuations—either above 253 V rms or below 207 V rms between line and neutral conductors—lasting more than 5 seconds. Upon detection, the charger disconnects the live, neutral, and earth connections to the vehicle, halting the charging process and indicating a red light. Once normal voltage is sensed for 30 seconds, the charger resumes its normal or charging mode, often indicated by a white pulsing light.

Response to PEN Fault Detection

When a PEN fault is detected, indicating an abnormal supply voltage, it’s essential for the owner to report this to the Distribution Network Operator (DNO) immediately. The DNO is responsible for investigating and rectifying the issue. For further diagnostic support, contacting the charger’s support, such as TeltoCharge, can provide additional insights.

Legal and Safety Importance

In the UK, legal requirements stipulate that EV chargers, especially those used outdoors, must have neutral fault protection when connected to a PME (Protective Multiple Earth) network. This regulation aims to prevent electric shocks in scenarios where the supply neutral is disconnected.

The UK’s electrical supply often combines earth and neutral in a single PEN conductor. If the PEN conductor becomes disconnected from earth, touching any object connected to it while also touching something grounded can lead to a dangerous, potentially fatal, electric shock. The PEN fault protection device or a dedicated earth for the EV charger is mandated to prevent such scenarios.

Exceptions and Considerations

While PEN fault protection is crucial, its necessity may vary depending on the availability of a true earth connection (TT or TN-S) and the condition of the earthing system. If there’s any doubt about the system’s integrity, installing PEN fault protection is non-negotiable for safety.

Should you have any questions on EV chargers and charging or specific questions on the Teltocharge range of EV chargers in the UK, please call our team of experts on 01449 888000 or email shop@linitx.com