PEN Fault Detection Devices & PME Protection Units
Our PEN fault detection devices and PME protection units are used on EV charger installations and other outdoor supplies connected to TN-C-S / PME earthing systems. They monitor the supply and disconnect the circuit if a PEN fault is detected, helping prevent dangerous touch voltages on exposed conductive parts.
This range includes standalone PEN protection devices, PME fault detection units, EV-ready boards and consumer units with integrated protection. Options are available for single-phase and three-phase installs, with SPD-ready configurations where surge protection is also required.
Quick answer: A PEN fault detection device, often called a PME fault detection device or PEN protection unit, monitors the incoming supply on TN-C-S systems. If a broken PEN conductor is detected, the device disconnects the load to reduce the risk of exposed metalwork becoming live.
Read more
These units are commonly specified for EV charger installs where the charger or supply arrangement needs open PEN fault protection without relying on an earth rod. They are also used on some outdoor and renewable energy installations where PME-related risk needs to be managed correctly.
- EV charger PEN protection – suitable where open PEN fault detection is required
- Single-phase and three-phase options – for domestic, commercial and multi-charge point installs
- Consumer unit and standalone devices – choose a full PME board or separate protection unit
- SPD-ready configurations – selected units include surge protection for cleaner EV board specification
For related EV protection, browse our EV-ready consumer units, surge protection devices and Type B RCDs.
3 Phase PME Fault Detection Unit 100A (WARB5100C/PME)
£90.00
The WARB5100C/PME is a 3 phase PME fault detection unit supplied as a 100A MCB + PME relay configuration. According to the manufacturer, this unit automatically monitors the supply voltage on both 400V and 415V supplies without the need for manual dip switch settings. Within...
PME Consumer Unit – 40A C Curve Type A RCBO, IP65 (WPEPME08/C40)
£96.45
The WPEPME08/C40 is an IP65-rated PME consumer unit pre-fitted with a 40A C Curve Type A RCBO and integrated PME fault detection relays. It eliminates the need for an earth rod in EV charger installations by safely isolating all conductors - live, neutral, and earth...
PME Fault Detection Consumer Unit – 4 Pole 40A RCBO with SPD (WMEPME08/SP)
£114.64
The WMEPME08/SP PME Fault Detection Consumer Unit is an 8-module metal board combining a 4 Pole 40A Type A RCBO with a Type 2 Surge Protection Device (SPD). It delivers full PME/PEN fault monitoring and automatic disconnection of Live, Neutral, and Earth within 5 seconds...
PME Consumer Unit – 40A C Curve Type A RCBO + SPD, IP65 (WPEPME08/SP)
£118.25
The WPEPME08/SP is an IP65 PME consumer unit pre-fitted with a 40A C Curve Type A RCBO, integrated PME fault detection relays, and a Type 2 Surge Protection Device (SPD). It ensures EV charger installations comply with 18th Edition Amendment 2 without the need for...
PME Consumer Unit – 40A MCB + SPD, IP65 (WPKPME08/SP)
£106.75
The WPKPME08/SP is a weatherproof PME consumer unit pre-fitted with a 40A MCB, integrated PME fault detection relays, and a Type 2 Surge Protection Device (SPD). It delivers full PEN fault isolation and surge protection in one compact IP65 enclosure, removing the need for an...
What Is a PEN Fault Detection Device?
A PEN fault detection device is designed to monitor the supply on TN-C-S / PME earthing systems and disconnect the load if a broken PEN conductor is detected. This is especially important for EV charger installations, where the vehicle and exposed metalwork may be outside the equipotential zone of the building.
You may also see these products described as PME fault detection devices, PEN protection devices, PEN fault units, PME detection units or open PEN protection devices. In trade use, they are all usually referring to the same protective function: detecting a dangerous PEN fault and disconnecting the supply.
Why PEN Fault Protection Matters for EV Chargers
EV charging is one of the main reasons installers need PEN fault protection. On a PME supply, a broken PEN conductor can create dangerous touch voltages on exposed conductive parts. A suitable PEN fault protection device for EV charger installs helps manage that risk without always needing to rely on an earth rod.
The exact protection route depends on the charger, earthing arrangement, site conditions and manufacturer requirements. Some EV chargers include built-in open PEN protection. Where they do not, or where a separate board is preferred, an external PEN protection unit or PME board may be specified.
PEN Protection Unit, PME Board or EV Consumer Unit?
The right product depends on how much of the installation you want to combine into one enclosure. A standalone device may be enough for some installs, while a complete EV consumer unit with PEN fault protection, RCBOs and surge protection can make the job cleaner.
| Product Type | Best Used For | Typical Benefit |
|---|---|---|
| Standalone PEN fault detection device | Adding open PEN protection to a defined circuit | Compact protection without changing the whole board setup |
| PME protection unit | EV or outdoor supplies on TN-C-S / PME systems | Clear disconnection route for PEN fault risk |
| EV consumer unit with PEN fault protection | Dedicated EV charger supplies | Combines PEN protection, circuit protection and often SPD in one board |
| 3 phase PEN fault detection device | Commercial EV chargers and multi-charge point installs | Suitable for larger three-phase supplies |
Single-Phase and 3 Phase PEN Fault Detection
Domestic EV charger installs usually need single-phase protection, while commercial EV charging and larger outdoor supplies may require a 3 phase PEN fault detection device. The selected unit should match the supply, load, protective device arrangement and enclosure requirements.
- Single-phase PEN protection – commonly used for domestic EV charger installs
- Three-phase PME fault detection – suited to commercial chargers, depots and multi-bay installations
- SPD-ready PME boards – useful where surge protection is also required for the EV supply
- IP-rated units – useful for external or exposed mounting positions where suitable
PEN Fault Detection With SPD Protection
Some EV installations require both open PEN protection and surge protection. A PEN fault detection device with SPD can reduce board complexity by combining protection types inside one enclosure.
For separate protection products, view our surge protection devices, RCBOs and Type B RCDs.
PME Fault Detection FAQs
What is PEN fault protection?
PEN fault protection monitors for a broken protective earth and neutral conductor on TN-C-S / PME supplies and disconnects the load if a fault condition is detected.
What is the difference between PME and PEN fault protection?
PME refers to the earthing arrangement. PEN refers to the combined protective earth and neutral conductor. In this product context, both terms are usually used around the same issue: detecting and disconnecting during a broken PEN fault.
Do EV chargers need PEN fault protection?
Many EV charger installations on PME supplies need open PEN protection, either built into the charger or provided externally through a suitable detection device or consumer unit.
Do I need an earth rod if I use a PEN fault detection device?
In many EV charger installations, open PEN fault detection can avoid the need for an earth rod. The correct approach depends on the installation design, charger specification and BS 7671 requirements.
Can I buy an EV consumer unit with PEN fault protection built in?
Yes. We stock EV consumer units and PME boards with integrated PEN fault protection, with selected options also including surge protection.
Do you stock 3 phase PEN fault detection devices?
Yes. Three-phase PEN fault detection options are available for commercial EV charger installs and larger PME-fed supplies.
UK-Stocked PME and PEN Protection Devices
Power & Data UK supplies PEN fault detection devices, PME protection units and EV consumer units with PEN fault protection for trade installs. Orders over £30 qualify for free UK mainland next-day delivery when placed before 2pm.