DLB stands for dynamic load balancing: a charger feature that measures how much current the whole building is drawing and turns the car’s charging current up or down so the supply is never overloaded. Behind those three letters sit four parts: a current sensor on the incoming supply, a link back to the charger, firmware settings made at installation, and a fail-safe for when the signal is lost. Knowing these parts tells you what to check on a datasheet and what to specify in an order.
Key Takeaways
- DLB means dynamic load balancing: charging current follows the building’s spare capacity.
- It relies on a sensor, a link, installer settings and a fail-safe.
- Specify sensor rating, phases, link, configuration access and fail-safe in orders.
- Supply sizing and installation stay with a qualified electrician.
The DLB Hardware Chain
Why homes need DLB, and how it differs from a fixed current limit, is covered in our article on dynamic load balancing for wallbox home chargers. Here is what does the work:
| Part | Common options | What to check |
|---|---|---|
| Sensor | Clamp-on current transformer (CT) on the incoming supply; or an energy meter with a data output | CT rating (for example 100 A), one sensor per phase on three-phase supplies, meter model supported |
| Link to the charger | Wired (often a two-wire data cable such as RS-485) or wireless | Maximum cable length, wireless range through walls, how the link is secured |
| Firmware settings | Maximum supply current, charger maximum, minimum charging current, per-phase balancing | Who can change settings and whether they are locked after installation |
| Fail-safe | Drop to a safe low current, or pause, if the sensor signal is lost | The default behavior and how the user is alerted |
What happens without a sensor is explained in our post on whether an EV charger works without a CT clamp.
How the Settings Work Together
An installer enters the supply limit, for example the main fuse or contracted capacity. The charger then calculates the headroom every few seconds: supply limit minus the building’s measured load equals the current the car may take, capped by the charger’s own maximum. The car is told the new limit through the control pilot signal, which every IEC 61851 or SAE J1772 charger uses to set charging current. If the headroom falls below the minimum current an EV can charge at, the charger pauses until load drops.
DLB does not add power; it uses spare capacity safely. Our article on whether load balancing increases charging speed explains the effect on charging times. Sizing the supply in the first place is an electrician’s job; see load calculation basics.
What to Specify in an OEM or Distributor Order
- Sensor type and rating: CT size, number of CTs, or supported meter models and protocol.
- Single- or three-phase balancing, and whether each phase is balanced separately.
- Link type and length: included cable length, or wireless range, and spare parts.
- Configuration method: app, local display or installer tool, with installer-only access to the supply limit.
- Fail-safe behavior when the sensor is disconnected.
- Multi-charger sharing: whether several chargers can share one supply, and whether this is done locally or through OCPP from a management platform.
- Compliance: in Great Britain, smart charge points sold for home use must meet the Electric Vehicles (Smart Charge Points) Regulations 2021, which also cover security.
In the US, recent NEC editions recognize energy management systems for EV loads, but how a system may be used in load calculations is decided by the electrician and the local inspector.
EVDANCE builds wallboxes such as the EV-ACT3204PE 22 kW wallbox (RFID and app control) for homes and small businesses, and the EV-AC03201T dual-connector AC station with OCPP 1.6J for shared sites. Brands can specify DLB sensors, settings and fail-safe behavior as part of a project through our OEM and private-label program.
Frequently Asked Questions
Is DLB the same as load management?
DLB is one kind of load management. “Load management” can also mean fixed limits, scheduling or sharing power across many chargers from a central system.
Where is the CT clamp installed?
Usually around the incoming supply cable near the meter or main panel. Installation must be done by a qualified electrician.
Does DLB need Wi-Fi?
Not necessarily. Many systems balance locally with a wired sensor. Wi-Fi is mainly for app access and updates.
Related Reading
- What Size EV Charger Can I Have at Home?
- White-Label Apps for Smart EV Chargers
- Smart Charging and Time-of-Use Tariffs
