Nexus 1250 User Manual

Discusses common three-phase power connections (Wye and Delta) and how to identify them.

Explains the characteristics of a Y-connected service, including neutral grounding and common voltages.

Describes Delta-connected services, phase-to-ground voltage behavior, and grounding practices.

Explains Blondel's Theorem for polyphase metering and its application in three-phase power measurement.

Differentiates between power, energy, and demand, explaining their units and measurement concepts.

Explains reactive power, power factor, and their components, including voltage and complex current.

Discusses harmonic distortion caused by non-linear loads and its effect on current waveforms.

Defines power quality and power quality problems as voltage, current, or frequency deviations causing system issues.

Introduces the Nexus® 1250/1252 meter, highlighting its revenue metering and power quality analysis features.

Details DNP V3.00 Level 1 and Level 2 features supported by Nexus meters.

Introduces the optional INP2 Internal Modem for remote communication via telephone lines.

Introduces the INP200 Ethernet Option for web server access and real-time data via Internet Explorer.

Lists formulas for calculating various electrical parameters like RMS voltage and current for Wye and Delta services.

Explains different demand averaging conventions like Block and Rolling Window Demand.

Details the specifications and types of optional external analog and digital I/O modules.

Provides detailed technical specifications for the Nexus® 1250/1252 meter, including electrical and environmental data.

Describes the procedure for upgrading the Nexus® 1252 meter's V-Switch key to access advanced features.

Details how to mount the Nexus® 1250/1252 meter securely, including environmental conditions.

Explains the mounting process for Nexus® LED external displays (P40N+, P41N+, P43N+).

Guides on mounting Nexus® external I/O modules, including bracket installation and connections.

Outlines safety precautions, installation requirements, and usage limitations for meter installation.

Provides guidance on correctly wiring monitored inputs and voltage connections, including CT/PT ratio programming.

Details the wiring requirements for current inputs, including insulation and cable specifications.

Guides on identifying and correcting CT connection reversals for accurate readings.

Explains how to connect AC and DC power sources to the Nexus® meter.

Lists available wiring diagrams for different connection configurations, including Wye and Delta systems.

Describes the EI-MSB10-400 surge protector for protecting substation equipment.

Overviews RS232, RS485, and RJ11 telephone line communication methods.

Details the RS232 connection procedure using Port 1, including cable length limits.

Explains RS485 communication for multiple devices, its distance viability, and port usage.

Guides on connecting to an RS485 master using converters like EIG's Unicom 2500.

Explains connecting the meter to a PC via RJ11 telephone line using the internal modem.

Describes the RJ45 network connection for the INP200 option, enabling multiple PC access.

Details the types of communication ports available on the Nexus® I/O modules.

Explains how to connect multiple Nexus® meters in series using RS485 and the maximum number of devices.

Overviews remote communication methods using RJ11 or RJ45 options and modems.

Describes how to use the meter's built-in High Speed Inputs for totalizing or logging.

Explains IRIG-B connections for precise event time-stamping synchronization with GPS satellite systems.

Lists alternative time synchronization methods including IRIG-B, Line Frequency, Internal Clock, and DNP.

Introduces the three available external displays (P40N+, P41N+, P43N+) and their basic functions.

Describes the P40N/P40N+, P41N+, and P43N+ displays and their roles as Master or Slave.

Explains how to navigate and view readings within the Dynamic Readings Mode.

Provides a visual map for navigating through the various readings in Dynamic Readings Mode.

Details how to access and navigate the Nexus® Information Mode, covering device time and communication settings.

Explains how to use Display Features Mode for resetting values, checking lamp tests, and managing display settings.

Defines loss compensation and explains its application in scenarios with separated metering and ownership points.

Explains how the Nexus® meter performs transformer loss compensation numerically using derived factors.

Details the information needed from transformer test reports for loss compensation calculations in three-element meters.

Introduces the TOU function, its availability via Communicator EXTTM software, and programmable rate structures.

Describes how to set up TOU calendars, assign schedules, and define fifteen-minute intervals.

Guides on enabling Daylight Savings Time and setting demand intervals and types.

Lists the components of all Nexus® External I/O modules and their general functions.

Refers to sections for installation instructions of external I/O modules.

Explains how to power I/O modules, including the use of external power sources like the EIG PSIO.

Shows how to connect multiple I/O modules and a PSIO power supply together.

Details factory settings for I/O modules and the procedure for using the reset button.

Presents specifications for Analog Transducer Signal Output Modules (0-1mA, 4-20mA).

Lists specifications for Analog Input Modules (0-1mA, 0-20mA, 0-5Vdc, 0-10Vdc).

Details specifications for the Digital Dry Contact Relay Output Module (4RO1).

Lists specifications for the Digital Solid State Pulse Output Module (4PO1).

Lists specifications for the Digital Status Input Module (8DI1).

Describes the hardware components of the INP2 option, including its modem capability for remote applications.

Explains the modem's dial-in function, including call detection, password checks, and data transfer.

Describes the dial-out function, allowing the meter to automatically report conditions or initiate calls.

Covers the hardware of the INP200 option, its Ethernet gateway function, and daisy-chaining capabilities.

Provides steps for setting up IP addresses and establishing network connections using RJ45.

Defines Flicker, its primary effects, and the standards used for its measurement.

Explains the internal process blocks used by the meter to model eye-brain response to voltage fluctuations.

Guides on configuring Flicker settings, including frequency, test times, and voltage normalization.

Describes the Flicker Polling screen functions for monitoring real-time Flicker data.

Explains the meter's capability to log Flicker values and download them to a Log Viewer.

Details the PQ Compliance analysis function for Nexus® 1252 meter with V-Switch key 2.

Describes the rack assembly, its components, and pre-wired setup for easy installation.

Guides on the physical installation process of the rack assembly onto a panel.

Defines CT Ratio for scaling current values from secondary to primary instrument transformer sides.

Defines PT Ratio for scaling voltage values from secondary to primary instrument transformer sides.

Defines RS232 as a serial network connection type between two devices with limited distance.

Defines RS485 as a serial network connection allowing multi-drop communication over longer distances.