# Current Transformer Shelly 400A Pro (model 3EM-400) — 400 A measurement for energy monitoring

**URL:** https://aio.lv/en/product--shelly-shelly-400a--12063429
**Data updated:** 2026-03-12 21:42 (EET)
**Category:** Other goods
**Manufacturer:** Shelly
**Manufacturer code:** SHELLY-400A
**EAN:** 3800235266496
**Warranty:** 2 Years
**Availability:** Available for order
**Price:** 60.49 €
**Prices and availability valid until:** 2026-08-01 23:59
**Price without VAT (21%):** 49.99 EUR
**Can be purchased by legal entities:** Yes (invoice)
**Buy:** https://aio.lv/en/product--shelly-shelly-400a--12063429

## Delivery options

| Delivery method | Delivery time | Cost |
|---|---|---|
| Office pickup (2b. Kengaraga str., Riga, Latvia, LV-1063) | 21.07.2026 | free |
| Pickup points | 24.07.2026 | 1.89 EUR |
| Courier delivery to door | 24.07.2026 | 4.99 EUR |

## Summary description

Shelly 400A Current Transformer Pro (3EM-400) is a clamp-style current transformer designed for measuring alternating current up to 400 A. Intended for energy monitoring and integration with Shelly systems, it provides accurate current sensing for metering, load analysis and protection. Useful in residential and commercial setups for monitoring circuits and collecting consumption data.

## Long description

Shelly 400A Current Transformer Pro (3EM-400) is a clamp-style sensor designed to measure alternating current up to 400 A for energy monitoring and integration with Shelly systems. The device provides a non-invasive method to capture real-time current values for metering, load analysis and fault detection. Its compact clamp form allows installation on single conductors in residential and commercial electrical panels without altering the circuit.
Advantages
The current transformer offers accurate AC current sensing up to 400 A with a clamp mechanism that enables quick installation without disconnecting wiring. It is engineered for compatibility with Shelly energy monitoring solutions and supports consistent data collection for load profiling and consumption reporting. The design reduces installation complexity and provides electrical isolation between the measured circuit and monitoring electronics.
Suitable for
 Measuring AC current on single-phase or three-phase circuits (up to 400 A per conductor)
 Integrating with Shelly controllers and energy monitoring systems for consumption tracking
 Load analysis, power distribution monitoring and preventative maintenance
 Residential and small commercial electrical panels where non-invasive measurement is required
Key specifications
 Measurement type: alternating current (AC)
 Maximum measurable current: 400 A
 Form factor: clamp-style (split-core) current transformer
 Output: sensor output compatible with Shelly metering inputs (voltage/current signal for integrative monitoring)
 Installation: non-invasive clamp-on mounting for single conductors
 Application: energy monitoring, load analysis and fault detection
How to use
Place the clamp-style transformer around the conductor to be measured ensuring the core closes fully and the conductor passes through the center of the clamp. Connect the transformer output to the corresponding input on the Shelly monitoring device following the manufacturer wiring diagram and polarity markings. Verify that the monitored circuit does not exceed 400 A and secure the clamp to prevent movement. After wiring, configure the Shelly device in its app or web interface to recognize the current transformer and calibrate the measurement if required.
Usage recommendations
For reliable readings, ensure the conductor passes cleanly through the center of the clamp and avoid bundling multiple conductors inside the clamp. Confirm compatibility with the specific Shelly monitoring model and follow local electrical safety practices: isolate power where necessary, use appropriate personal protective equipment, and consult a qualified electrician for installation in high-current or complex systems.

## FAQ

### How much does the Shelly Current Transformer 400A Pro (3EM-400) cost, and is it available for purchase?

The price is 60.49 € (valid at the time of publication and already includes all taxes). The item is available for order — 105 pcs. are in stock, and you can place your purchase right now with delivery across Latvia and Europe or choose pickup at the Riga collection point. We offer favorable purchase terms, including the option to split the payment into convenient monthly installments. Availability and price are updated in real time, so we recommend placing your order in advance.

### If I order this product today, when will I receive my order?

If you place your order today, delivery will be as fast and convenient as possible. You will be able to pick up your order on 21.07.2026 at the Riga pickup point or choose delivery across Latvia and Europe. We carefully inspect every purchase and pack it securely for safe transportation.

### What payment options are available?

AiO.lv offers several payment methods: Bank transfer, Bank cards on-line, Apple Pay, Google Pay. All transactions are 100% secure and encrypted.

### Can this product be purchased for a company (with VAT)?

Yes. AiO.lv works with legal entities in Latvia and across Europe. The product price already includes VAT. For certain product categories, as well as for companies from other EU countries with a valid VAT number, a 0% VAT rate may apply. We issue the invoice immediately after the order is placed, support electronic BIS invoices, and automatically generate all necessary accounting documents. You can complete the purchase for a company online — simply select the company profile and choose bank transfer as the payment method during checkout.

### What is the warranty period?

All Shelly products come with an official 2 Years warranty. It covers all manufacturing defects and malfunctions that may occur during use. The warranty is valid at all authorized Shelly service centers and through AiO.lv

### Can the product be returned after purchase?

Yes, you can return the product within 14 days of purchase if you bought it as a consumer (not a legal entity). Returns are possible without giving any reason — the main condition is that the product retains its original appearance and full set of accessories. We will make the process as simple and convenient as possible: just contact our customer support team, and we will help you arrange the return.

### Where should I contact for warranty service?

For warranty-related questions you can contact the AiO.lv (SIA VSPRO) customer support team. More information about warranty service: https://aio.lv/en/warranty

## Image

https://aio.lv/img/cache/product/12063429/67548801_large.webp