| Typical application | Apartments, small offices, lighting circuits, and individual loads | Small commercial buildings, workshops, and balanced or unbalanced three-phase loads | Large feeders, industrial panels, solar inverters, and high-current installations | Remote sites, multi-location portfolios, tenant billing, and utility-style monitoring |
| Electrical system | 1-phase, typically 120/230 V AC | 3-phase, typically 230/400 V AC or regional equivalent | 3-phase voltage input with external current transformers | 1-phase or 3-phase, depending on the certified model |
| Current measurement | Direct current path; commonly 5–45 A or 5–100 A | Direct current path; commonly up to 63–100 A per phase | External CTs; common primary ratings range from 100 A to 2,000 A | Direct or CT-connected; rating must match the certified installation configuration |
| Core measurements | Voltage, current, active power, power factor, frequency, and imported energy | Per-phase voltage/current, total active power, reactive power, power factor, and energy | Per-phase values, bidirectional active energy, reactive energy, demand, and power factor | Certified energy registers, time-of-use data, demand, event logs, and tamper records |
| Typical active-energy accuracy | Often Class 1 or equivalent for monitoring applications | Often Class 1; some models provide higher accuracy under specified conditions | Commonly Class 0.5 or Class 1, depending on meter and CT accuracy | May be Class 0.5S, Class 0.2S, or another approved class; certification is essential |
| Wireless communication | Wi-Fi, Bluetooth commissioning, or sub-GHz mesh | Wi-Fi, Ethernet gateway, sub-GHz mesh, or RS-485 gateway | Sub-GHz mesh, Wi-Fi gateway, Ethernet, or private cellular gateway | LTE-M, NB-IoT, 4G, or another regionally supported cellular service |
| Recommended data interval | 1–15 minutes for energy dashboards and load trends | 1–15 minutes for phase comparison and facility monitoring | 1–5 minutes for demand analysis; shorter intervals may increase storage and network needs | 15-minute intervals are common for billing and demand analysis; configurable by service plan |
| Bidirectional energy | Optional; confirm separate import and export registers | Usually available on models designed for distributed generation | Strongly recommended for solar, storage, and microgrid applications | Normally required when energy settlement or export compensation is involved |
| Power-quality features | Basic frequency and power-factor monitoring | Voltage imbalance, phase loss, frequency, and power factor may be included | May include harmonics, voltage sag or swell detection, and phase imbalance | Select only if the certified meter specifies sampling method and power-quality accuracy |
| Demand measurement | Optional rolling demand, commonly based on 5–30-minute intervals | Useful for small commercial peak-demand tracking | Recommended for industrial load management and capacity planning | Should support the interval and calculation method required by the tariff or billing rule |
| Data storage during outages | Often limited local memory; verify records and time-stamp retention | Typically stores recent intervals locally or through a gateway | Prefer non-volatile memory with configurable interval history | Should include non-volatile interval storage and store-and-forward transmission |
| Installation and safety | DIN-rail mounting; qualified electrical installation required | Panel installation with phase identification and correct torque requirements | CT polarity, phase sequence, burden, insulation, and shorting arrangements must be checked | Use an approved wiring diagram, sealed interfaces where required, and a qualified installer |
| Security requirements | Encrypted wireless connection, unique credentials, and secure firmware updates | Device authentication, encrypted transport, and role-based access are recommended | Add certificate-based authentication, network segmentation, and audit logging | Require secure boot or signed firmware where available, encrypted cellular transport, and remote credential management |
| Best choice when | You need affordable circuit-level visibility with simple installation | You need phase-by-phase monitoring for a small or medium facility | The load exceeds direct-meter current limits or requires flexible CT ratios | The meter supports commercial settlement, remote access, and multi-site deployment |