Shelly Pro 3EM (120A) | Wi-Fi & LAN, 3-Phase Smart Energy Meter

What buyers think

Buyer-review evidence points to a few clear themes: installation and setup are generally described as straightforward once the wiring plan is in place, and the app experience is commonly described as polished and full-featured for monitoring and control. For solar users, the device is often valued for making it easy to capture energy data and integrate it into automation workflows (including via API-style access). A smaller set of comments highlight practical limitations, such as occasional data download or connection behavior, and the reality that solar/panel wiring layout can affect how “easy” the overall install feels.

What this meter is for

The Shelly Pro 3EM (120A) is designed for people who want more than a simple “whole-house” power reading. It measures on three phases, tracks how much energy is being produced and used (2-way consumption), and exposes real-time values you can use for monitoring, alerts, and automation scenarios.

It’s particularly relevant for:

• Solar and storage monitoring, where you want visibility into production and consumption behavior per phase
• Home and office electrical monitoring, to spot trends across circuits and appliances
• DIY smart home and automation projects, where connectivity plus data access matters

Key features that affect day-to-day use

3-phase monitoring with 2-way energy tracking

The core job of the Pro 3EM is to measure power and energy for each of three phases. It also supports 2-way consumption, tracking produced versus used energy per phase, which is the feature that makes it a natural fit for solar-aware automation and reporting.

Wi‑Fi and LAN connectivity, plus Bluetooth gateway

Connectivity is split across Wi‑Fi and LAN (Ethernet), which helps if your home network has spotty Wi‑Fi coverage near the breaker panel. The device also acts as a Bluetooth gateway, expanding how you can connect with other Shelly devices in a local smart home setup.

Electrical metrics for power-quality style insights

Beyond basic energy totals, it supports reporting and monitoring of multiple electrical measurements, including voltage (RMS by phase), active and reactive power, power factor, and energy variants. If your goal is to understand how loads behave, this broader measurement set can be useful.

Security and integrations for more advanced users

The device includes mTLS for secure communications in MQTT, HTTP, and secure outbound WebSockets, aimed at safer integration into cloud or networked setups. It also supports scripting and MQTT, plus MODBUS support for voltage/current/power/energy style access.

Setup and wiring caveats to know

Smart energy meters live or die by installation correctness. Review patterns and product behavior expectations both point to wiring accuracy as the biggest “make it work” factor.

• CT transformers must be positioned and matched correctly. If CTs are connected to the wrong phase/port or oriented incorrectly, readings can be off.
• Neutral wiring is mandatory. If your electrical box or planned installation does not include a usable neutral, you may run into compatibility problems.
• CT size matters. This model is intended for 120A CTs (the package includes three 120A CTs).
• Solar installs may require extra panel-to-DIN box runs. If your solar equipment or panel layout does not already support DIN-box style placement, expect some wiring planning.

Pros and cons (in plain terms)

When it’s a smart buy

• You want 3-phase energy monitoring with phase-by-phase detail.
• You care about solar production vs. usage (2-way consumption) and want real-time plus historical-style insight (up to 60 days).
• You value network flexibility (Wi‑Fi plus LAN) and prefer a setup that can support automation and integrations.
• You’re comfortable with DIN-rail breaker-box installation and checking wiring accuracy.

When you should look elsewhere

• Your priority is a simpler plug-in style meter (this is built for panel-level installs).
• You cannot provide neutral wiring to the meter location.
• You are not willing to validate CT/phase wiring for accurate readings.
• Your solar setup design relies on having the electronics integrated inside the panel in a way that avoids running wires to a DIN box.

Verdict: is Shelly Pro 3EM (120A) worth it?

The Shelly Pro 3EM (120A) is worth considering if you want serious 3-phase measurement, solar-aware 2-way consumption tracking, and connectivity options that suit both home automation and more technical integrations. It becomes a strong value when you have the right wiring conditions (including neutral) and you’re prepared to install and match the CTs correctly. If your setup can’t accommodate those requirements, you may spend more time working around installation constraints than you’d like.

Price and availability

Pricing can vary by seller and region. For the most up-to-date cost and current stock status, check the listing.

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