The Point of Common Coupling (PCC) is the electrical point where a customer’s installation connects to the wider electricity network and where multiple users may share the same upstream supply. In simple terms, it is the grid connection interface used to assess how your site affects (and is affected by) the public network.
For EV charging projects, the PCC serves as the reference point for evaluating power quality, maximum demand, and compliance with utility or grid code requirements.
Why the PCC Matters in EV Charging
EV charging sites can introduce large, dynamic loads and power-electronics effects. The PCC is important because it is typically where:
– Utilities define connection capacity and contractual limits (import/export)
– Power quality limits are assessed (e.g., harmonics, flicker, voltage variation)
– Compliance with the grid code or connection agreements is measured
– Responsibility boundaries are set between the DSO/utility and the site owner/operator
– Monitoring is placed for disputes, audits, and performance verification
Where the PCC Is Located
The PCC location depends on site ownership and network configuration, but it is commonly at:
– The service connection point at the utility supply terminals
– The customer’s main incoming switchboard (main LV panel)
– The main meter point (where revenue metering is installed)
– The boundary point defined in the grid connection agreement
For multi-tenant sites, the PCC may be upstream of tenant sub-meters, at the building incomer.
What Is Typically Measured at the PCC
Measurements at the PCC often include:
– Voltage (per phase) and voltage stability events (sags/swells)
– Current and maximum demand (kW/kVA) over interval periods
– Power factor and reactive power (kvar)
– Total Harmonic Distortion (THD) and harmonic spectrum
– Flicker and rapid voltage changes (site-dependent)
– Event logging for outages, phase loss, and abnormal conditions
PCC in EV Charging Design and Operation
In EV charging, PCC data is used to:
– Size and configure load management and maximum site demand limits
– Validate whether more chargers can be added without grid upgrades
– Determine if passive harmonic filters or other mitigation is required
– Support commissioning and acceptance testing against connection conditions
– Provide evidence for troubleshooting when the grid is weak or constrained
– Coordinate with on-site generation and storage where present (PV/BESS)
Practical Considerations
– The PCC is a defined boundary, not always the physically closest switchboard
– Power quality at the PCC can differ from measurements at individual chargers due to internal wiring and diversity
– In mixed-load sites, separating EV load metering from total-site PCC metering improves diagnostics
– Data quality matters: time sync, correct CT orientation, and consistent interval definitions
Related Glossary Terms
Grid Connection Agreement
Import Capacity
Maximum Demand
Maximum Site Demand Limit
Interval Metering
Power Quality
Harmonic Distortion
Total Harmonic Distortion (THD)
Power Factor (PF)
Load Management