Meter cabinets are dedicated enclosures that house electricity metering equipment and related electrical components used to measure, protect, and sometimes control the power supplied to a building, sub-installation, or EV charging site. In EV charging projects, meter cabinets are commonly used to support billing, cost allocation, energy monitoring, and compliance requirements (such as MID metering where applicable).
What Are Meter Cabinets?
A meter cabinet is an enclosure—indoor or outdoor—designed to accommodate:
– Utility or private electricity meters (single-phase or three-phase)
– Current transformers (CTs) and metering terminals
– Protective devices (fuses, MCB/MCCB, isolators) depending on design
– Communication modules (e.g., Ethernet, cellular, RS485) for remote reading
– Sealing points for tamper resistance where required
Meter cabinets can be part of a larger main LV panel or a standalone enclosure placed near the site boundary or charging area.
Why Meter Cabinets Matter for EV Charging
Accurate metering is essential for commercial charging operations. Meter cabinets help:
– Measure energy delivered for driver billing (€/kWh)
– Separate EV charging energy from building consumption
– Enable tenant or cost-center allocation in workplaces and real estate
– Support charging carbon reporting and sustainability KPIs
– Provide a clear interface point for utilities and site operators
– Simplify integration with CPMS and energy management systems
For public charging, metering can also support regulatory requirements related to transparency and consumer protection.
Common Use Cases in EV Charging Sites
– A dedicated meter for the entire EV charging distribution (site-level EV energy)
– Sub-metering per charger group (rows, zones, tenants)
– Metering for revenue share agreements (site owner vs CPO)
– Monitoring import/export when combined with PV or storage
– External “boundary” cabinets for curbside or car park installations
Typical Components Inside a Meter Cabinet
– Electricity meter (direct-connected or CT-operated)
– CTs sized for feeder current, with correct polarity and wiring
– Main isolator switch for safe maintenance and commissioning
– Overcurrent protection (fuses or breakers) for meter and auxiliary circuits
– Surge protection (optional, depending on site design)
– Communication gateway for remote reads and alarms
– Cable terminations and labeling for all incoming/outgoing feeders
Key Design Considerations
– Cabinet rating: IP and IK protection for outdoor and public locations
– Accessibility: safe maintenance access for meter reading and service
– Sealing/tamper protection where legally required
– Space for CTs, wiring, comms modules, and future upgrades
– Correct thermal design and ventilation for electronics
– Clear labeling to support troubleshooting and audits
– Compliance with utility requirements for placement, type approval, and inspection
Meter Cabinets vs Charger-Integrated Metering
Meter cabinet metering (site or feeder level)
– Measures total EV charging supply or a distribution segment
– Useful for cost allocation, grid monitoring, and site energy limits
Charger-integrated metering
– Measures per-session energy at the charger
– Needed for driver billing, tariffs, and detailed session reporting
Many deployments use both: charger metering for billing and a cabinet meter for site totals and validation.
Common Problems
– Incorrect CT sizing or wiring leading to inaccurate readings
– Poor cabinet sealing causing moisture damage and communication failures
– Meter placed in inaccessible locations (locked rooms, behind barriers)
– Missing documentation of meter IDs and wiring, complicating reconciliation
– Insufficient space for expansions (additional feeders or communication gear)
Related Glossary Terms
Energy meter
CT (Current transformer)
MID metering
Main LV panels
Sub-metering
Tariff structure
CPMS
Charging session reporting
Maintenance access
Load balancing