---
title: Shelly 120A CT Pro 3EM Split Core Current Transformer For Shelly Pro 3EM
date: 2025-10-13T05:35:35Z
modified: 2026-05-05T16:50:17Z
permalink: "https://tech.co.za/product/shelly-120a-ct-pro-3em-split-core-current-transformer-for-shelly-pro-3em/"
type: product
status: publish
excerpt: The Shelly 120A Current transformer scale the largevalues of current to small, standardized values for measuring purposes. Theyprovide a secondary current that is accurately proportional to the currentflowing in its primary circuit. The current transformer presents a negligibleload to the primary circuit. * Only compatible with Shelly Pro 3EM-120A Features Snap-on, screwless mounting system
wpid: 554674
product_brand:
  - Shelly
product_type:
  - simple
product_visibility:
  - featured
product_cat:
  - Smart Home
featured_image: "https://tech.co.za/wp-content/uploads/2025/10/SHELLY-120A-CT-PRO-3EM.png"
---

The Shelly 120A Current transformer scale the largevalues of current to small, standardized values for measuring purposes. Theyprovide a secondary current that is accurately proportional to the currentflowing in its primary circuit. The current transformer presents a negligibleload to the primary circuit. \* Only compatible with Shelly Pro 3EM-120A Features Snap-on, screwless mounting system

### Diagrams

**INSTALLATION**

![](https://shellysa.co.za/wp-content/uploads/2025/06/CT-cable.png)

**LEGEND**



| **A** | Shelly CT120A |
| --- | --- |
| **B** | Cable tie (another one on the opposite side) |
| **C** | Primary conductor |