Does every variant of this PME consumer unit include PEN fault detection?

Yes. PEN fault detection and the 40A RCBO are included as standard on every variant. Surge protection, kWh metering, and load balancing are optional extras that can be added in any combination.

What is the difference between the IP40 metal and IP65 plastic PME consumer unit?

Both units offer identical protection and the same optional extras. The IP40 uses a metal enclosure for indoor use only (garages, utility rooms). The IP65 uses a weatherproof plastic enclosure suitable for outdoor or exposed mounting.

What does load balancing do on an EV charger consumer unit?

Load balancing monitors total property electricity consumption and automatically reduces the charger's output current when overall demand is high, preventing the supply fuse from tripping. Most useful where supply capacity is limited or high-demand appliances run alongside the charger.

2 reviews

By WCED

Fitted Consumer Unit IP40 – PME + 40A RCBO (Surge Protection + kWh Meter + Load Balancing Options Available)

Name: Fitted Consumer Unit IP40 – PME + 40A RCBO (Surge Protection + kWh Meter + Load Balancing Options Available)
Brand: WCED
SKU: Wmepme08/sp
Availability: InStock

£88.00 - £135.00

£96.00

Supplied and supported by Eco Harmony — your trusted UK specialist for EV charging and electrical protection.

1-Year Warranty

Fast UK Shipping

Single & Three Phase

IP40 & IP65 Rated

Hugely Customisable

Standard Shipping 3-5 Buisness days£10

Express Shipping 1-2 Buisness days£20

SKU: Wmepme08/sp

Collections:

This single-phase PME consumer unit provides PEN fault detection and 40A RCBO protection as standard, in a robust metal IP40-rated enclosure. It is designed for domestic EV charger installations on PME (TN-C-S) supplies where the charger does not include built-in PEN fault detection. Select from optional add-ons — surge protection, kWh metering, and load balancing — to build the exact specification your installation requires.

PEN fault protection is included as standard on every variant. All options of this product include the PEN fault detection module and 40A RCBO. The optional extras let you add surge protection, energy monitoring, and load balancing — choose only what your installation needs. For the outdoor weatherproof version, see the IP65 plastic version.

IP40 — indoor use only. This metal enclosure is rated IP40 and is suitable for protected indoor locations such as garages, utility rooms, and plant rooms. It should not be mounted in exposed outdoor locations or where it may be subject to rain or condensation. For outdoor mounting, choose the IP65 weatherproof version.

Included as standard on every variant

PEN fault detection module — monitors supply voltage continuously, disconnects the charger within 5 seconds on fault detection
40A Type A RCBO — combined residual current and overcurrent protection
Metal IP40 enclosure — DIN rail mounted, pre-wired, ready to connect

Optional extras — select when ordering

Option	What it adds	When to choose it
Surge Protection Optional	Type 2 SPD — protects charger electronics from transient overvoltages caused by lightning and grid switching	Recommended for most installs. BS7671 Amendment 2 risk assessment almost always requires it
kWh Meter Optional	Records how much electricity the EV charger uses over time	Rental properties, workplace charging, HMRC mileage reimbursement, or any install where usage tracking is needed
Load Balancing Optional	Monitors whole-home consumption and automatically reduces charger output to prevent the supply fuse from tripping	Where incoming supply capacity is limited or other high-demand appliances (showers, ovens, heat pumps) run alongside the charger

All optional extras can be combined. For example, you can order surge protection + kWh meter + load balancing all in a single unit. Select your required combination when adding to basket.

Technical specifications

Specification	Detail
Supply type	Single-phase TN-C-S (PME)
PEN fault detection	Included as standard — all variants
RCBO rating	40A, Type A
Enclosure type	Metal
Enclosure rating	IP40 (indoor use only)
PEN fault trip threshold	<207V or >253V
Disconnect time	Within 5 seconds
Surge protection	Type 2 SPD — optional add-on
kWh metering	Optional add-on
Load balancing	Optional add-on
Mounting	35mm DIN rail, wall-mountable
Regulation compliance	BS 7671:2018 Amendment 2, Reg 722.411.4.1
Suitable for	Single-phase 7kW EV chargers, domestic installs

IP40 vs IP65 — which version do you need?

	This unit — IP40 Metal	IP65 Plastic version
Enclosure	Metal	Plastic
IP rating	IP40 — indoor only	IP65 — outdoor rated
Suitable for	Garage, utility room, plant room	External walls, exposed outdoor locations
PEN fault detection	Included as standard	Included as standard
Optional extras	Surge, kWh meter, load balancing	Surge, kWh meter, load balancing

Frequently asked questions

Does every variant include PEN fault detection?

Yes. PEN fault detection and the 40A RCBO are included as standard on every option of this product. The optional extras — surge protection, kWh metering, and load balancing — are additions on top. You cannot order this unit without PEN fault detection.

Do I need to add surge protection?

BS 7671 Amendment 2 requires a risk assessment for surge protection on EV charger circuits. In practice, the assessment almost always concludes that Type 2 surge protection is needed — modern EV charger electronics are vulnerable to transient overvoltages from lightning and grid switching. It is strongly recommended for most installs and is already included if you select that option.

When would I need a kWh meter?

A kWh meter records how much electricity the EV charger has consumed. Common uses include: rental properties where the landlord wants to recover the cost of electricity from tenants; workplace charging where employees claim HMRC mileage reimbursement; commercial installs requiring per-session energy billing; or any install where usage data is needed.

What does load balancing do and do I need it?

Load balancing monitors the total electricity consumption at the property and automatically reduces the EV charger's output current when overall demand is high — preventing the main supply fuse from tripping. It is particularly useful where the incoming supply is limited (e.g. 60A or 80A single-phase), or where an electric shower, oven, or heat pump may run at the same time as the charger.

What is the difference between this and the IP65 version?

The two products are identical in function and available options — both include PEN fault detection as standard and offer the same surge protection, kWh meter, and load balancing extras. The only difference is the enclosure: this unit uses a metal IP40 enclosure for indoor use only, while the IP65 version uses a weatherproof plastic enclosure suitable for outdoor or exposed mounting.

Does this unit remove the need for an earth rod?

Yes. A compliant PEN fault detection device is a recognised alternative to a TT earthing system under BS 7671 Amendment 2. No earth rod or groundworks are required when this unit is installed.

Related products and resources

IP65 Outdoor Version 3-Phase PEN Unit Product Finder PME FAQs Understanding PEN Protection

PEN Fault Detection — Standard IP40 Metal Indoor Use Single-Phase 40A RCBO Optional Surge Optional kWh Meter Optional Load Balancing BS 7671 Compliant No Earth Rod UK Stock