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Product Overview
The Allen-Bradley 1408-EM3A-ENT is a compact, DIN-rail mountable three-phase power and energy monitoring device from the Rockwell Automation PowerMonitor 1000 series, designed to provide accurate real-time electrical measurements and energy consumption data for industrial, commercial, and utility applications. It functions as a cost-effective sub-metering and load-analysis solution that connects directly to potential transformers (PTs) up to 600 V AC line-to-line and current transformers (CTs) with 5 A or 1 A secondaries, computing voltage, current, active/reactive/apparent power, power factor, frequency, and cumulative energy (kWh, kVARh) for cost allocation and sustainability reporting. The Allen-Bradley 1408-EM3A-ENT features a built-in 10/100 Mbps EtherNet/IP port for seamless integration into Logix-based control systems (ControlLogix, CompactLogix) as an Add-On Profile (AOP) device, as well as Modbus TCP server capability for third-party SCADA and building management systems.Equipped with an integral backlit LCD display showing RMS voltage/current, power, energy, and basic harmonics up to the 31st order, the Allen-Bradley 1408-EM3A-ENT also embeds a web server that allows technicians to view real-time values, configure parameters, and download logged data through a standard web browser—no proprietary software required for basic setup. An auxiliary RS-485 port supports Modbus RTU or DF1 protocols for legacy networks. The unit provides programmable KYZ pulse outputs (solid-state relay contacts) proportional to accumulated energy for interfacing with utility-grade pulse totalizers, plus two digital status inputs for capturing external events such as demand-reset triggers or circuit-breaker auxiliary contacts.Positioned between basic panel meters and high-end power quality analyzers, the Allen-Bradley 1408-EM3A-ENT delivers Class 1 energy accuracy (IEC 62053-21) with voltage/current measurement accuracy of ±0.5%, making it ideally suited for departmental cost-center allocation, motor load profiling, and identifying inefficient equipment in retrofit energy-saving projects. Its small footprint (approx. 100 mm tall) conserves valuable panel space while giving plant engineers actionable visibility into electrical system performance, helping justify capital upgrades and verify the ROI of energy-efficiency initiatives.
Technical Specifications
| Product Model | 1408-EM3A-ENT |
|---|---|
| Manufacturer | Rockwell Automation / Allen-Bradley |
| Product Type | Three-Phase Power & Energy Monitor (PowerMonitor 1000 Series) |
| Voltage Input (Direct) | 57–600 V AC Line-to-Line, 50–347 V AC Line-to-Neutral (CAT III 600 V) |
| Current Input | 0–5 A or 0–1 A AC via External CT (supports PT ratios up to 600 kV, CT ratios up to 65,000:5) |
| Frequency Range | 40–75 Hz (auto-sensing) |
| Measurement Accuracy | Voltage ±0.5% FS, Current ±0.5% FS, Power/Energy Class 1 (±1% FS) |
| Harmonics Analysis | RMS values up to 31st harmonic order |
| Communication Ports | 1 × 10/100Base-TX EtherNet/IP (Explicit & Implicit Messaging), 1 × RS-485 (Modbus RTU / DF1) |
| Embedded Web Server | Yes, HTML pages for config, real-time data, log download |
| Digital I/O | 2 × Digital Status Inputs (dry contact), 1 × KYZ Pulse Output (DPDT solid-state, 120 V AC/DC max) |
| Display | Backlit Alphanumeric LCD (local viewing of V, A, kW, kWh, PF, Hz) |
| Power Supply | 100–240 V AC, 50/60 Hz (self-powered from voltage inputs) |
| Operating Temperature | -10 °C to +60 °C (14 °F to 140 °F) |
| Enclosure / Mounting | IP20, 35 mm DIN Rail Mount |
| Dimensions (H×W×D) | 100 × 72 × 105 mm (approx.) |
| Weight | 0.38 kg |
Main Features and Advantages
Native EtherNet/IP integration with Logix controllers: The Allen-Bradley 1408-EM3A-ENT includes a Rockwell Automation Add-On Profile (AOP) that allows drag-and-drop addition to a ControlLogix or CompactLogix I/O tree. Once commissioned, the controller can read energy totals, demand values, and instantaneous power data directly into user tags via implicit (cyclic) messaging, eliminating custom ASCII parsing or third-party gateway hardware. This tight integration means energy data becomes just another process variable in the control system—available for alarming, trending, or MES upload.Cost-center energy allocation and sub-metering: Many plants struggle to quantify which production line, department, or ancillary system consumes the most electricity. The Allen-Bradley 1408-EM3A-ENT solves this by delivering revenue-grade kWh/kVARh accumulation with programmable pulse scaling on its KYZ output, suitable for interfacing with existing utility pulse totalizers or standalone data loggers. Four quadrant energy measurement distinguishes imported vs. exported energy, which is essential for facilities with on-site generation (solar, co-gen) or regenerative drives.Browser-based configuration and diagnostics: Unlike older serial-only power meters, the Allen-Bradley 1408-EM3A-ENT hosts its own web pages. An electrician or energy engineer can connect a laptop to the same VLAN, browse to the meter’s IP address, and view phasor diagrams, unbalance percentages, min/max logs, and harmonic distortion—all without installing software. Firmware updates, time synchronization (SNTP), and parameter backups are also handled through the web interface, speeding commissioning and reducing laptop-dependency in the field.Compact DIN-rail form factor with local display: At roughly the height of three standard DIN modules, the Allen-Bradley 1408-EM3A-ENT fits easily into crowded MCC (Motor Control Center) buckets, panelboards, or UPS distribution panels. The onboard LCD removes the need for a separate panel-mounted display in many applications, showing key values during walkthrough inspections without opening a laptop or HMI screen.Programmable demand and logging functions: The Allen-Bradley 1408-EM3A-ENT can compute sliding-window or fixed-interval demand (kW/kVAR), store min/max/average snapshots, and log energy data to internal non-volatile memory. These logs persist through power cycles and can be retrieved via EtherNet/IP or the web server, supporting ISO 50001energy management audits and utility bill reconciliation.
Application Field
The Allen-Bradley 1408-EM3A-ENT is deployed wherever granular electrical consumption data is needed for cost allocation, efficiency improvement, or compliance reporting. In multi-line manufacturing facilities—such as automotive assembly, food & beverage processing, or discrete parts machining—the Allen-Bradley 1408-EM3A-ENT is installed on the feeder breakers supplying individual production cells, paint booths, ovens, or compressor rooms. This enables the plant energy manager to generate department-level utility bills, compare shift-over-shift consumption, and correlate energy use with production output (specific energy per unit produced). When a line shows abnormally high kWh per unit, the Allen-Bradley 1408-EM3A-ENT data—including demand peaks and voltage imbalance—helps pinpoint whether the issue is a poorly tuned drive, an oversized motor running unloaded, or a failing power factor correction capacitor bank.In commercial buildings, data centers, and institutional campuses (hospitals, universities), the Allen-Bradley 1408-EM3A-ENT sub-meters major loads such as chillers, AHUs, elevator banks, and server-room PDUs. Facility teams use the EtherNet/IP feed to push interval data into a BAS or energy dashboard for LEED/EPC certification tracking and demand-response program participation. Water/wastewater treatment plants apply the Allen-Bradley 1408-EM3A-ENT to large pump feeds and aeration blowers, often pairing it with a Micro850 or CompactLogix controller that triggers alarms when pump energy deviates from baseline—an early indicator of clogged impellers or excessive backpressure. Across all these scenarios, the Allen-Bradley 1408-EM3A-ENT closes the visibility gap between the utility revenue meter and the actual loads that drive the bill.
