Lovato SM1R4000 motor protection circuit breaker with adjustable 30 to 40 A thermal protection, 20 kA breaking capacity and rotary knob operation.
£177.99
The Lovato SM1R4000 is a robust and reliable motor protection circuit breaker designed to protect three-phase motors against overloads, short circuits and phase failure conditions. As part of the Lovato SM1R series, it combines magnetic and thermal protection with rotary knob operation, making it suitable for industrial machinery, OEM equipment and motor control panels.
This manual motor starter offers an adjustable thermal protection range of 30 to 40 A, providing accurate protection for higher-current industrial motor circuits. Its compact design and dependable switching performance make it ideal for demanding motor control applications where safety, reliability and ease of installation are essential.
With a rated current of 40 A, a 3-pole configuration and a 20 kA breaking capacity at 400 V AC, the SM1R4000 delivers dependable motor protection whilst remaining suitable for DIN rail or screw mounting inside electrical control systems.
Motor protection circuit breakers such as the Lovato SM1R4000 protect electric motors by disconnecting the supply during overload, short-circuit or phase failure conditions. This helps reduce the risk of motor damage, improve equipment reliability and minimise unplanned downtime within industrial installations.
The SM1R series is widely used by machine builders and panel manufacturers thanks to its compact footprint, dependable protection characteristics and straightforward installation. Its adjustable thermal setting allows accurate matching to the connected motor for improved operational reliability.
| Phase | Three Phase |
|---|---|
| Manufacturer | Lovato Electric |
| Series | SM1R |
| Model | SM1R4000 |
| Product type | Motor protection circuit breaker |
| Rated current | 40 A |
| Thermal trip adjustment range | 30 to 40 A |
| Number of poles | 3 |
| Type of protection | Magnetic and thermal |
| Phase failure protection | Yes |
| Type of control | Rotary knob |
| Short-circuit breaking capacity Icu at 400 V AC | 20 kA |
| Rated insulation voltage Ui | 690 V AC |
| Rated impulse withstand voltage Uimp | 6 kV |
| Frequency | 50 / 60 Hz |
| Tripping class | 10A |
| Protection rating | IP20 |
| Mounting type | 35 mm DIN rail / screw mounting |
| Approximate dimensions | 97 × 45 × 91 mm |
| Operating temperature | -20 to +60 °C |
| HS Code | 85362010 |
The Lovato SM1R4000 protects three-phase motors against overloads, short circuits and phase failure conditions.
The adjustable thermal protection range is 30 to 40 A.
The breaker provides a short-circuit breaking capacity of 20 kA at 400 V AC.
Yes. The breaker provides phase failure sensitive protection in addition to thermal and magnetic motor protection.
It is designed for installation on a standard 35 mm DIN rail or by screw mounting inside electrical control panels and motor control centres.
Lovato SM1R motor protection circuit breakers are trusted by machine builders, automation engineers and industrial panel builders for dependable motor protection, reliable switching performance and long service life.
● Service Agreements
Credit Accounts
Our service agreements are built to support long term procurement relationships. By working closely with engineering teams and procurement departments, we help streamline purchasing processes while ensuring consistent access to critical components and sourcing support when it matters most.
● frequently asked questions
At Led Controls Ltd we help engineers source the right automation and control gear with confidence. below are quick answers to what we are asked most often.
We supply all leading manfacturers in our industry. we offer next day delivery on most poplour products.
Your content goes here. Edit or remove this text inline or in the module Content settings. You can also style every aspect of this content in the module Design settings and even apply custom CSS to this text in the module Advanced settings.
Your content goes here. Edit or remove this text inline or in the module Content settings. You can also style every aspect of this content in the module Design settings and even apply custom CSS to this text in the module Advanced settings.
Your content goes here. Edit or remove this text inline or in the module Content settings. You can also style every aspect of this content in the module Design settings and even apply custom CSS to this text in the module Advanced settings.
Your content goes here. Edit or remove this text inline or in the module Content settings. You can also style every aspect of this content in the module Design settings and even apply custom CSS to this text in the module Advanced settings.
● latest blog
LED Controls is a specialist distributor of factory automation and industrial controls, supplying OEMs, machine builders, panel builders and end users throughout the UK and worldwide. As a trusted UK distributor for many of the world’s leading automation manufacturers, we provide industrial control products, technical expertise and bespoke automation solutions backed by outstanding customer service.
2025 has been a big year for LED Controls, and our blog has expanded accordingly. We've covered a wide range of topics across industrial control and factory automation this year. From core technology explainers and new product releases to panel building best practice...
2025 has been a big year for LED Controls, and our blog has expanded accordingly. We've covered a wide range of topics across industrial control and factory automation this year. From core technology explainers and new product releases to panel building best practice...