Summary

Every EV chargepoint installation starts with the same question: can the existing electrical supply carry the extra load safely? A 32A chargepoint on a single-phase domestic supply adds a demand roughly equivalent to an electric shower running continuously for hours at a time — and unlike a shower, it's often left running overnight unattended. BS 7671 Chapter 722 makes the supply capacity assessment a formal requirement of the installation, not an optional check, and where the assessment shows the supply can't take the chargepoint's full current alongside existing loads without risk, some form of load management is the answer.

"Load management" isn't one product — it's a category covering several genuinely different techniques, each solving a slightly different problem. A single-property domestic install with a modest fuse and an electric shower usually needs dynamic load management reacting in real time to household demand. A site with several chargepoints sharing one incoming supply — a workplace car park, a fleet depot, a block of flats' communal parking — needs a different layer of load balancing across chargepoints, not just against household load. And in some cases the constraint isn't the customer's fuse at all but the capacity of the local electricity network, which the DNO controls through its own notification and demand-limiting requirements.

This article surveys when each type of load management applies and which method fits. For the detailed mechanics of the most common domestic method — CT clamp dynamic load management — see ct clamp load management, which this article deliberately doesn't repeat.

Key Facts

Quick Reference Table: Load Management Methods

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Method Protects Complexity/Cost Best Suited To Key Limitation
Static/fixed load limiting Customer's main fuse Low — set once at commissioning, no extra hardware Single chargepoint, predictable and modest other loads Permanently caps charge rate even when headroom exists
Dynamic Load Management (CT clamp) Customer's main fuse, in real time Moderate — CT clamp + compatible chargepoint Most single-property domestic and light commercial installs Requires a chargepoint that supports CT input; response time 10–60s (see ct clamp load management)
DNO network demand limit / ADS-type restriction Local electricity network (transformer/feeder capacity) Set by DNO as a condition of connection approval Larger installs, multiple chargepoints, constrained local network areas Outside the installer's control; may cap charging regardless of the customer's own headroom
EVSCR default off-peak restriction Wider national network peak demand Built into compliant chargepoint firmware All domestic/workplace chargepoints sold in GB (mandatory) Not a site-specific load management measure — a national demand-shaping default
Multi-unit dynamic load balancing Shared supply across several chargepoints Higher — central controller/gateway plus per-chargepoint communication Workplace car parks, fleet depots, blocks of flats with communal parking Needs compatible chargepoints/platform across the whole site; more complex commissioning
Supply/fuse upgrade Removes the constraint rather than managing it DNO-dependent cost and lead time Sites where load management would leave charging unacceptably slow Not always available or cost-effective; DNO lead times can be long

Detailed Guidance

When load management is actually needed

Not every EV chargepoint install needs load management — the BS 7671 Chapter 722.312.2 assessment is what determines whether it does. As a working rule of thumb, load management should be seriously considered where any of the following apply:

Conversely, a well-specified 100A supply with modest other loads (no electric shower, no immersion heater running at the same time as likely charging windows) may pass the assessment without any load management at all — always run and document the assessment rather than defaulting to fitting load management "just in case," since it adds cost and complexity that isn't always needed.

Static/fixed load limiting — the simple option

Where a chargepoint doesn't support (or the budget doesn't stretch to) real-time CT clamp sensing, a static load limit sets a single, permanently reduced maximum charge current at commissioning — for example, capping a 32A chargepoint to 16A or 20A based on a worst-case assessment of the supply's remaining headroom after other loads.

This is the simplest and cheapest form of load management: no sensor, no signal cable, no ongoing calculation — just a lower current ceiling programmed into the chargepoint. The trade-off is that it's always conservative. If the static limit is set to 16A to protect against a worst-case scenario (shower running, cooker on), the chargepoint charges at that reduced rate even at 3am when nothing else in the house is drawing any current at all — headroom that dynamic load management would have used automatically.

Static limiting suits sites where the other loads are well understood, relatively constant, and the customer doesn't need maximum charge speed — for example, a smaller flat with limited other appliances, or as an interim measure before a full DLM-capable chargepoint is specified.

Dynamic Load Management — the standard domestic answer

For most single-property domestic and light commercial installs where the supply assessment shows a real constraint, CT clamp-based dynamic load management is the standard specification. It measures actual household demand in real time and adjusts the chargepoint's output to use whatever headroom is available at any given moment, rather than assuming the worst case permanently.

The installation, commissioning, and troubleshooting detail for this method — CT clamp positioning, signal cabling, three-phase considerations, and multi-chargepoint peer balancing on a single property — is covered fully in ct clamp load management and isn't repeated here.

DNO network-level demand limits — a different constraint entirely

It's important not to conflate protecting the customer's own main fuse with protecting the wider electricity network — they're different problems requiring different solutions, and only one of them (the fuse) is something the installer's own load management choice controls.

Where a chargepoint installation — particularly a larger single install, or several chargepoints on one site — is notified to the DNO under the ENA G98/G99/G100 connection framework, the DNO assesses whether the local network infrastructure (the transformer feeding the area, the feeder cable) has spare capacity. In areas of known constraint, the DNO can require the installation to include a demand-limiting device or agreed maximum import capacity as a condition of connection approval, independent of whatever load management the installer has fitted to protect the customer's own fuse.

This matters practically: a site can have a perfectly good CT clamp DLM system protecting the customer's fuse, and still be required by the DNO to observe a lower overall import limit for network reasons. Always check DNO notification requirements and any resulting conditions separately from the on-site load management design — see domestic ev charger installation process for the full notification sequence.

Multi-unit dynamic load balancing — several chargepoints, one shared supply

Workplace car parks, fleet depots, and blocks of flats with communal parking present a different problem again: multiple chargepoints drawing from one shared incoming supply, where no single chargepoint's household CT clamp reading is the relevant measure — the constraint is the site's total available capacity shared across however many vehicles are charging at once.

Multi-unit dynamic load balancing extends the load management concept with a central controller or gateway that:

PAS 1878 (Energy Smart Appliances: System Functionality and Architecture Code of Practice) sets out the functional architecture for smart appliances — including EV chargepoints and the platforms managing them — to receive and act on demand signals, and underpins the smart functionality requirements referenced in the Electric Vehicles (Smart Charge Points) Regulations 2021. For multi-unit sites, specifying chargepoints and a management platform that follow this shared architecture is what allows load balancing to work across units from potentially different manufacturers, rather than requiring a single-vendor closed system.

Multi-unit sites need commissioning discipline beyond a single-property CT clamp job: every chargepoint on the shared supply must be part of the same load balancing group, the site's true available capacity (not just one building's fuse rating) must be correctly configured, and any DNO-imposed network demand limit (see above) needs to sit as a ceiling above the load balancing platform's own allocation logic, not in conflict with it.

Choosing a supply upgrade instead of load management

Load management — of any type — is a way of living within an existing supply's constraints. Where the constraints are severe enough that even good dynamic load management would leave charging unacceptably slow or unreliable (for example, two EVs plus a heat pump on an 80A supply with an electric shower), it's worth costing a DNO fuse or supply upgrade as an alternative, rather than compromising indefinitely with aggressive load management. Supply upgrades have DNO-dependent cost and lead times that vary significantly by area and should be raised with the customer early in the quoting process, not as an afterthought once load management has proven inadequate on site.

Frequently Asked Questions

Do I need load management on every EV chargepoint install?

No — it's determined by the BS 7671 Chapter 722.312.2 supply assessment, not applied as a default. A property with a solid 100A supply and no other major simultaneous loads may pass without any load management. Always run and document the assessment; don't fit load management reflexively, and don't skip it either.

What's the difference between load management protecting my fuse and a DNO demand limit?

Load management (static or dynamic) protects the customer's own main fuse from overload caused by the property's own loads. A DNO demand limit protects the shared local electricity network (the transformer and cables serving multiple properties) from being overloaded by aggregate demand across an area — it's imposed by the DNO as a condition of connection, is unrelated to what's happening inside any one property, and can apply even where the customer's own fuse has plenty of headroom.

Is static load limiting ever the right permanent choice, or should I always push for dynamic?

Static limiting is a legitimate permanent choice for simpler sites — a small flat with modest, predictable other loads, or a budget-constrained install where the chargepoint doesn't support CT input. Dynamic load management is generally preferable where it's affordable and supported, because it uses available headroom rather than permanently sacrificing charge speed, but it isn't mandatory in every case.

How is a workplace or fleet site different from a single domestic CT clamp install?

A single-property CT clamp reacts to that property's household load and protects that property's fuse. A workplace or fleet site with several chargepoints sharing one supply needs a central load balancing layer that allocates capacity across all the chargepoints, not just each one independently sensing the same site load — otherwise multiple chargepoints could each try to draw full current simultaneously and collectively overload the shared supply even though each individual unit's own sensing looked fine.

Regulations & Standards