Wireless Electricity Monitor
Class 1 precision electricity monitoring for commercial and industrial buildings. Measure real power, reactive power, voltage, current, power factor, and energy consumption wirelessly across three-phase circuits.
Revenue-Grade Power Measurement
The ZEM series meets IEC 62053-21 Class 1 (ZEM-61) and IEC 62053-22 Class 0.5S (ZEM-63) accuracy standards, delivering the precision required for sub-metering, tenant billing, and energy performance verification. Each unit measures real power (kW), reactive power (kVAR), apparent power (kVA), voltage, current, power factor, and cumulative energy (kWh) across all three phases simultaneously. Housed in IP67 waterproof polycarbonate enclosures, ZEM monitors can be installed inside or outside electrical panels, indoors or outdoors. This level of accuracy ensures reliable data for energy audits, ISO 50001 compliance, and M&V programmes.
Split-Core and Rogowski Current Transformers
Split-core CTs clip around existing cables for retrofit without downtime. Rogowski flexible coils handle larger conductors up to 3kA. All CTs are factory paired and calibrated with the ZEM for system-level accuracy.
ZigBee Mesh Networking
Every ZEM unit joins the EpiSensor ZigBee mesh network, transmitting measurement data wirelessly to the gateway. The self-healing mesh topology means each mains-powered ZEM also acts as a router for other devices, extending network coverage throughout the building. No data cables need to be run between meters and the gateway, reducing installation costs by up to 80% compared to wired monitoring systems.
ZEM-61 and ZEM-63: Built for Different Requirements
Both the ZEM-61 and ZEM-63 are full three-phase electricity monitors. The ZEM-61 delivers Class 1 accuracy in an IP67 waterproof enclosure, with up to 36 data feeds, 10,000 data point logging, and support for split-core or Rogowski CTs from 120A to 3000A. The ZEM-63 is the next-generation model with Class 0.5S revenue-grade accuracy (IEC 62053-22), 70,000 data points of local storage, support for both 3-wire and 4-wire configurations, optional relay output (4A/250VAC), optional power amplifier (+20dBm), and tamper-evident seals for billing applications.
Flexible Data Intervals and Local Storage
Configure reporting intervals from 1 second to 15 minutes depending on your application requirements. High-frequency sampling is available for power quality analysis and demand response verification, while longer intervals conserve bandwidth for large-scale deployments. The ZEM stores data locally during any network interruption, automatically backfilling to the gateway when connectivity is restored to ensure no data is lost.
Specifications
| Models | ZEM-61 (Class 1), ZEM-63 (Class 0.5S) |
| Accuracy | Class 1 (ZEM-61) / Class 0.5S per IEC 62053-22 (ZEM-63) |
| Voltage Range | 75-470VAC (ZEM-61) / 110-480VAC (ZEM-63) |
| Current Range | 0.1A to 3kA (depending on CT) |
| CT Types | Split-core mA / Flexible Rogowski coil (factory paired) |
| Wiring | 3-phase / 4-wire (ZEM-61) / 3-wire or 4-wire (ZEM-63) |
| Measurements | V, I, kW, kVAR, kVA, PF, kWh, frequency |
| Wireless | ZigBee Pro, 2.4 GHz ISM, mesh topology |
| Tx Power | +5dBm (ZEM-61) / +8dBm or +20dBm with power amp (ZEM-63) |
| IP Rating | IP67 (IEC 60529) |
| Enclosure | Waterproof polycarbonate |
| Dimensions | 192 x 128 x 40mm (ZEM-61) / 185 x 155 x 34mm (ZEM-63) |
| Operating Temperature | -30°C to +55°C (ZEM-61) / -30°C to +60°C (ZEM-63) |
| Power Supply | From 3-phase voltage reference or 85-265V AC auxiliary |
| Data Logging | 10,000 points (ZEM-61) / 70,000 points (ZEM-63) |
| Reporting Interval | 1 second to 15 minutes (configurable) |
| Certifications | CE, RoHS, WEEE (ZEM-61) / CE, RoHS, WEEE, FCC, IC (ZEM-63) |
Use Cases
Sub-Metering
Monitor individual circuits, floors, or tenants within commercial buildings for accurate energy allocation and billing.
Energy Auditing
Identify energy waste and verify savings from efficiency measures with continuous, high-resolution power data.
ISO 50001 Compliance
Provide the measurement infrastructure required for energy management system certification and ongoing compliance.
Related Products
ZGW-10 Gateway
ZGWThe central hub that collects data from all ZEM monitors and delivers it to your platform.
Learn MoreDemand Response Controller
ZDRCombine metering with load control for closed-loop demand response.
Learn MoreWireless Digital Signal Sensor
ZPC/ZDICapture pulse outputs from utility meters for gas, water, and heat monitoring.
Learn MoreReady to Monitor Your Energy?
Talk to our team to learn how the ZEM series can deliver accurate electricity monitoring across your buildings.