Approved Simultaneous Contact Protection Devices
The Institution of Engineering and Technology (IET) Wiring Regulations BS 7671 describes how the risk from ‘simultaneous contact’ can be mitigated by maintaining a 2.5m touch-distance between devices connected to different earths.
Where it is not possible to be sure that the distance of a plugged-in EV will always be at least 2.5 meters from differently earthed street furniture or other charging cars then a qualified electrician must install an Earth Current Trip device such as IET01 ‘Method 3’ (or equivalent) device at the resident’s home.
Earth Current Trip devices are now readily available in the UK and are either built into some chargers or can be installed as a standalone device during charger installation.
The Zappi products below incorporate myenergi’s patented PEN (Protective Earth Neutral) fault protection. This monitors current in the protective conductor (PE) and disconnects all live and earth conductors when a fault current exceeds defined tripping thresholds in 0.3 seconds or less.
This provides protection against electric shocks in the event of simultaneous contact with conductors at different earth potentials, making the chargers suitable for both TN and TT systems.
Zappi 2.1
From £899 fully installed.
One of the UK’s most popular chargers - British-made and famous for its smart tariff and solar compatibility.
Available with a 6.5m cable or socketed so you can use your own cable.
Zappi Glow
From £899 fully installed.
Myenergi’s sleek looking charger sports a compact design, all while keeping the same build quality from the British manufacturer.
Fully compatible with smart tariffs such as Ovo Anytime or Octopus Intelligent Go.
Currently only available with a 6.5m tethered cable - a socketed version will be released in 2026.
If you choose a charger that does not have a simultaneous contact protection device built in (like the myenergi Zappi charger) then your electrician can install a matt:e MTE/A11-100M1b device. This device is installed in your consumer unit or electricity meter.
The 21 mA detection threshold in this device is specifically calibrated to identify elevated touch voltages that may arise and pass current where simultaneous contact with secondary earthing or bonding systems occurs - be it TNCS, TNS or TT earthing systems.
By operating at this sensitivity, the unit provides timely detection and isolation in accordance with IET 01 requirements, without reliance on assumptions about external earthing arrangements.
MTE/A11-100M1b
Professionally installed by your electrician, either at the time of your charger install or as a retrofit.