The labels 120/240V, 120/208V and 277/480V describe different electrical service questions. They are not interchangeable shopping categories. Confirm the actual service from existing documentation and with your utility or a qualified electrical professional before selecting monitoring equipment.
This guide explains what to bring to that conversation. It does not instruct you to open a panel, identify exposed conductors, attach current transformers or connect voltage-reference wires.
1. Start With the Documented Service
A building’s incoming service and an individual appliance circuit are different things. The words single-phase or three-phase, a building type, or the number printed on an appliance do not establish the complete installation requirements.
Keep three questions separate: what service supplies the property, what a particular circuit or appliance requires, and what the proposed monitor is documented to support. A useful comparison starts with those records rather than an assumption about a house, apartment or commercial building.
2. Understanding 120/240V Split-Phase
Many U.S. homes use a 120/240V split-phase supply. In that nominal arrangement, either hot leg is 120V to neutral and the two hot legs are 240V apart. Split-phase is a form of single-phase supply; it is not a separate category that automatically produces energy savings.
Eaton’s explanation of network configurations provides background on these relationships. A conceptual diagram does not identify your property’s service or specify how equipment should be connected.
For a monitoring enquiry, ask which documented supply points need to be measured and which exact monitor and CT bundle the professional proposes.
3. Understanding 120/208V Three-Phase Wye
In a nominal 120/208V four-wire wye system, each phase is 120V to neutral and a pair of phases is 208V apart. That example is not a description of every three-phase service.
The service arrangement, the equipment requirements and the intended measurement scope still need to be checked together. An appliance with a different voltage label is not shown to be compatible merely because both labels appear in a three-phase discussion.
Eaton’s comparison of single- and three-phase power explains the general phase relationship. Use the property’s own records for the installation question.
4. Reviewing a Site Documented as 277/480V
If the service records describe 277/480V, provide those records to the qualified professional reviewing the installation. Include the exact monitor model and its current documentation in the same review.
A product described as three-phase is not automatically approved for every three-phase arrangement. This guide does not establish a compatible Grus model, authorize work on that service, or replace the selected equipment’s instructions.
5. Comparing Grus Monitoring Options
Use the Energy Monitoring category and monitor buying guide to compare intended measurement coverage. A whole-supply reading, selected circuit readings and measurements involving generation are different requirements.
Product pages for WattPanel-2X, WattNet-3 and WattPanel-3X are starting points for the relevant model information, not a voltage-to-product approval table. Check the current product destination and exact model documentation before making a selection.
Ask about the supported service, the selected CT ratings, included versus optional sensors, and the intended measurement points. Do not assume that a meter controls EV charging, optimizes a battery, identifies every appliance or integrates with a particular platform.
6. Confirming the Property and the Measurement Scope
Use existing service records and equipment documentation. Ask the utility or a qualified electrical professional to resolve anything unclear. Building use, breaker count and wire colours are not sufficient evidence of the supply.
Prepare a short enquiry describing the property, the documented service label, the exact product under consideration and the readings you need. Do not remove a panel cover or take electrical measurements to complete this guide.
7. Planning Professional Installation and Handoff
The professional’s review should establish equipment suitability and installation scope before work starts. The selected model’s instructions, not a general Blog diagram, govern the equipment-specific requirements. Use manuals or contact support to request the exact documents when they are not available publicly.
Arrange a handoff that identifies the installed model, the measurement labels, what each channel represents and who will answer a question or fault. Check that the displayed readings correspond to the documented measurement scope before interpreting patterns.
8. Reading Data Without Assuming Savings
After professional installation, use labelled readings to compare similar periods and record relevant changes in occupancy, weather or schedules. Apply the actual tariff when considering costs.
Monitoring does not establish a guaranteed reduction in bills, automatic AI advice, reduced downtime or a specific payback period. It supplies information for a decision; any proposed change still needs its own suitability and outcome check.
Choose the Next Step
Read the home power terminology guide, compare the monitoring options, or bring the documented service and exact product question to Grus support.
