Energy monitoring · Product spotlight
Shelly Pro 3EM 3CT63: see where household energy goes
A DIN-rail energy meter with a combined 63A transformer. Plan the installation and the use of its readings together.
Researched
Our recommendation
Useful for professionally installed phase-level monitoring and local automation. The meter does not switch loads by itself, and small-load accounting has a documented threshold.
- Current range
- 0–63A per measured phase
- Network
- Ethernet, 2.4GHz Wi-Fi and Bluetooth for setup
- Local history
- About 60 days at one-minute intervals; non-volatile storage
One white meter with one combined three-phase 63A current transformer; not the 120A clamp version.
Affiliate links may earn us a commission. Check the exact variant and current price. Specifications are manufacturer claims, not our own test results.
Decide what you want to measure
Pro 3EM 3CT63 is useful when you want phase-level energy information rather than a single plug-in appliance reading. Its records can help you compare daily patterns or follow an installed solar or charging system.
The linked kit contains a combined three-phase 63A transformer. This is a specific mechanical arrangement, not three interchangeable 120A clamps. Have the installer check the conductors, panel space and intended measuring points before buying.
Make installation part of the purchase
This device connects inside an electrical distribution system and needs a qualified electrician. The current transformer measures without a direct current-path connection, but that does not make the complete installation a harmless clip-on task.
Include professional installation and any required protective components in the project. Even Ethernet connection changes have manufacturer precautions. Plan network access with the installer so routine monitoring does not require opening the cabinet.
Look at patterns, not just a live number
The meter records voltage, current, power and accumulated energy. Local history at one-minute intervals lets you inspect how demand changes over a day, while import/export readings can support a suitable solar monitoring arrangement.
A reading does not identify every appliance automatically. Give the monitored circuits useful names and compare similar periods. Weather, occupancy and charging schedules can change consumption without indicating a fault or a permanent saving.
Keep the small-load limit visible
Shelly documents a no-load threshold of 30VA per channel. Below its threshold condition, power can still appear while consumed energy is not added to the statistics. That matters if your main interest is a collection of tiny standby loads.
Current accuracy also varies by range. Read the complete table instead of treating the headline one-percent figure as universal. We have not calibrated a unit or verified suitability for billing.
Separate measurement from switching
Ethernet, Wi-Fi, local interfaces and automation protocols make this useful for an existing monitoring system. Cloud operation is optional; decide where records will be stored and exported before depending on long-term history.
There is no built-in load relay. Switching requires the compatible add-on and appropriate external hardware, designed by the installer. Choose this kit for its documented measurement and integration features, with installation fit and small-load behaviour accepted in advance.
Technical details
Specifications and compatibility.
| Specification | Details |
|---|---|
| Current range | 0–63A per measured phase |
| Network | Ethernet, 2.4GHz Wi-Fi and Bluetooth for setup |
| Local history | About 60 days at one-minute intervals; non-volatile storage |
| Linked version | SPEM-003CEBEU63, white; B0DJF6VQHK |
| Quantity / package | One Pro 3EM meter and one combined 3CT63 transformer assembly |
| Installation | DIN rail; qualified electrician; compatible panel layout and neutral required |
| Supply | 100–260V AC, 50/60Hz; below 3W consumption |
| External protection | B/C characteristic, 16A maximum, at least 6kA interrupting rating, energy-limiting class 3; installer to specify |
| Voltage measurement | 100–260V AC; ±1% stated accuracy |
| Current accuracy | ±1% at 2–63A; ±2% at 1–2A; ±5% at 0–1A |
| Energy accuracy | Class B active energy; manufacturer design/test claim |
| Measurements | Voltage, current, active/apparent power and energy, power factor, fundamental active/reactive energy |
| Direction | Four-quadrant import/export measurement |
| No-load threshold | 30VA per channel; below the documented threshold, power can display without energy accumulation |
| Calibration condition | Channel-to-channel calibration requires at least 500W per channel |
| Data exports | CSV for recorded PQ values; JSON through RPC |
| Protocols | Modbus TCP, MQTT, RPC, HTTP and WebSocket |
| Local operation | Embedded web interface and scripting; cloud optional |
| Wi-Fi / Bluetooth | 802.11b/g/n, 2.4GHz; Bluetooth 4.2 |
| Built-in relay | None; separate Pro 3EM Switch Add-on and contactor needed for load control |
| Meter size / weight | 94 × 19 × 69mm; 62g |
| Transformer size / weight | 14 × 54 × 26mm; 32g |
| Transformer aperture | 9mm conductor opening |
| Operating conditions | -20–40°C; 30–70% RH; maximum altitude 2000m |
| Temperature sensor | Internal sensing and reporting |
| Optional neutral CT | Separate; not included |
| Network servicing | Manufacturer requires power off before LAN connection changes; touchable connector parts must be non-metallic |
| Billing suitability | No billing-meter approval established by this research |
A good fit if…
You have a suitable electrical installation and want an electrician to add phase-level monitoring with local data access.
Keep in mind
Professional installation required. No built-in relay; 63A transformer geometry must fit. Small-load energy accumulation has a threshold.