This guide explains how to wire IAMMETER meters in typical residential solar monitoring scenarios. All wiring examples in this guide are designed for simultaneous grid-side and inverter-side monitoring.
By measuring both grid import/export and inverter generation, IAMMETER-Cloud can calculate solar production, grid consumption, exported energy, and self-consumption correctly.
The wiring method depends on the power system type:
Before installation, always confirm your grid type, inverter output type, and whether any additional load circuit also needs to be monitored.
This article only covers wiring diagrams for home solar monitoring. For complete IAMMETER wiring diagrams and installation instructions, please refer to the IAMMETER Wiring & Installation Guide: https://www.iammeter.com/blog/wiring-installation-guide
CT direction is one of the most important points in solar monitoring wiring.
IAMMETER CTs are marked with a K -> L direction arrow. In home solar applications, follow these rules:
If a CT is installed in reverse, the meter will still work, but the power reading may become negative or the import/export direction may be reversed.
This is the most common residential solar setup. Both the utility grid and the inverter output are single-phase.
To monitor a complete single-phase solar system, both the grid connection and the inverter output should be measured:
For this scenario, IAMMETER recommends either:
WEM2067: a dual-channel meter for home solar and split-phase monitoring, designed for residential users and bundled with IAMMETER-Cloud Basic serviceWEM3050T: a three-phase meter designed for home users, bundled with IAMMETER-Cloud Basic service, and well suited for using one meter as multiple single-phase measurement channelsWEM2067 |
WEM3050T |
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If you need a three-phase meter for commercial or industrial projects, or if you prefer IAMMETER-Cloud Pro, refer to the IAMMETER meter selection guide:
WEM2067 provides two measurement channels, which is suitable for a single-phase solar system with:
This is a simple solution when the system only requires grid and inverter monitoring, without an additional load circuit.
WEM3050T is a three-phase meter, but in home solar applications it can also work as three independent single-phase measurement channels:
If you do not need to monitor an extra load, the third channel can remain unused.
Important notes for WEM3050T:
WEM3050T must be powered correctly to operate.After wiring, if you use IAMMETER-Cloud, set the correct Use Type for each channel, such as:
GridInverterLoadThis allows IAMMETER-Cloud to calculate solar generation, imported/exported energy, and self-consumption correctly.
Split-phase systems are common in North America. In this type of system, the grid side is usually split-phase, while the inverter may be:
For split-phase home solar, the recommended model is WEM3050T, a three-phase meter designed for home users and bundled with IAMMETER-Cloud Basic service.
If you prefer IAMMETER-Cloud Pro or need to compare with other three-phase models, see:
Use the three channels like this:
This method allows one IAMMETER three-phase meter to monitor both:
A split-phase inverter normally has two output lines, L1 and L2. In this wiring example, Phase C measures only one inverter output line.
Since the two split-phase inverter output lines are typically balanced, you can set ctcratio = 2 for Phase C. IAMMETER will then double the measured Phase C power, which is equivalent to measuring both L1 and L2 inverter outputs.
If the inverter is single-phase and you measure the actual inverter output line directly, you usually do not need to set ctcratio.
As with all other solar wiring scenarios, pay close attention to CT direction:
Three-phase residential or light commercial solar systems are also common in some markets. The required meter combination depends on whether the grid and inverter are single-phase or three-phase.
If both the grid and the inverter are three-phase, and you want to monitor both sides of the system, you need at least two three-phase meters:
In this setup:
After installation, set their Use Type correctly in IAMMETER-Cloud:
GridInverterIf you want IAMMETER-Cloud Pro instead of Basic, or if you want to compare with professional three-phase models such as WEM3080T or WEM3046T, use this selection guide:
If the grid is three-phase but the inverter is single-phase, the recommended solution is:
For the inverter side, WEM3080 is the recommended single-phase model. For the grid side, the recommended meter is WEM3050T.
This combination provides accurate monitoring for both grid import/export and PV generation.
Symptom:
Fix:
This mainly affects three-phase installations.
Symptom:
Fix:
This is especially important for WEM3050T.
Fix:
If you are selecting an IAMMETER meter for home solar monitoring, use this quick guide:
WEM2067 or WEM3050TWEM3050TWEM3050TWEM3050T + one WEM3080For most home solar users, WEM3050T is the most flexible option because it is designed for residential applications and can cover many common wiring scenarios.
Three Phase Wi-Fi Energy Meter (WEM3080T)
Single Phase Wi-Fi Energy Meter (WEM3080)
Three Phase Wi-Fi Energy Meter (WEM3046T)
Three Phase Wi-Fi Energy Meter (WEM3050T)