VAT:
Quotes
  • 0
    • Electrical4less Logo
    0
    Electrical4less Reviews 4.9 Based on 1485 reviews
    UK Mainland Free Delivery £75 + VAT
    30 Day Return Policy
    Next Day Delivery Cut Off Time 3PM*

    Motor Protection Circuit Breakers

    Motor Protection Circuit Breakers (MPCB) provide reliable protection for electric motors against overload, phase failure and short-circuit conditions. Designed for manual motor starting and isolation, these adjustable protection devices are widely used in industrial control panels, machinery installations and motor starter systems.

    Hager MM508N Motor Protection Circuit Breaker

    Hager | MM501N | Motor Protection Circuit Breaker | 3P 0.1–0.16A
    Delivery usually within 1 - 3 working days *
    SKU: MM501N
    £154.92
    Hager MM508N Motor Protection Circuit Breaker

    Hager | MM508N | Motor Protection Circuit Breaker | 3P 2.5–4A
    Delivery usually within 1 - 3 working days *
    SKU: MM508N
    £120.04
    Hager MM509N Motor Protection Circuit Breaker

    Hager | MM509N | Motor Protection Circuit Breaker | 3P 4–6.3A
    Delivery usually within 1 - 3 working days *
    SKU: MM509N
    £127.23
    Hager MM510N Motor Protection Circuit Breaker

    Hager | MM510N | Motor Protection Circuit Breaker | 3P 6.3–10A
    Delivery usually within 1 - 3 working days *
    SKU: MM510N
    £128.44
    Hager MZ520N Auxiliary Contact

    Hager | MZ520N | Auxiliary Contact 1NC+1NO for Motor Starter
    Delivery usually within 1 - 3 working days *
    SKU: MZ520N
    £30.42
    Hager MZ527N Alarm Contact

    Hager | MZ527N | Alarm Contact 2CO for Motor Starter
    Delivery usually within 1 - 3 working days *
    SKU: MZ527N
    £23.76
    Hager MZ528N Under Voltage Release

    Hager | MZ528N | Under Voltage Release | 230V AC for Motor Starter
    Delivery usually within 1 - 3 working days *
    SKU: MZ528N
    £37.73
    Hager MZ529N Under Voltage Release

    Hager | MZ529N | Under Voltage Release 400V AC for Motor Starter
    Delivery usually within 1 - 3 working days *
    SKU: MZ529N
    £34.44
    Hager MZ530N Emergency Stop Button

    Hager | MZ530N | IP66 | External Emergency Stop Button
    Delivery usually within 1 - 3 working days *
    SKU: MZ530N
    £37.71

    Motor Protection Circuit Breakers

    Motor protection circuit breakers are specialised protective devices designed to safeguard electric motors from overload, short-circuit and phase loss conditions. Unlike standard miniature circuit breakers, MPCBs are specifically calibrated to match motor characteristics and allow adjustable current settings for accurate protection.

    These devices combine several functions in a single compact unit, including motor isolation, manual switching and thermal-magnetic protection. This makes them ideal for motor starter assemblies, control panels and industrial automation systems.

    Adjustable Motor Protection

    Most motor protection circuit breakers feature adjustable current settings, allowing the protection level to be matched precisely to the rated current of the motor. This ensures reliable operation while preventing nuisance tripping during motor start-up.

    Typical Applications

    Motor protection circuit breakers are commonly used in:

    • Industrial machinery and manufacturing equipment
    • Pump and compressor systems
    • Conveyor systems
    • HVAC motors and ventilation equipment
    • Control panels and motor starter assemblies

    Motor Starter Accessories

    Many motor protection switches can be expanded with compatible accessories to create a complete motor control solution. Available accessories may include auxiliary contacts, alarm contacts, undervoltage releases, enclosures and emergency stop devices.

    These additions allow the motor protection breaker to be integrated into control circuits, signalling systems and safety installations.

    Key Features

    • Adjustable motor current protection
    • Combined overload and short-circuit protection
    • Manual motor starting and isolation
    • Compact DIN-rail installation
    • Compatible accessories for expanded functional





    © 2026 Electrical4less
    We accept Visa We accept Mastercard We accept Maestro We accept PayPal We use Amazon Pay We use Apple Pay We use Google Pay
    Next Day Delivery

    Cut-Off Time and Order Information
    To ensure your order qualifies for next day delivery, please place your order by 3:00 PM. This is subject to all items being available on the shelf at the time of your order. For orders where the total value exceeds £150 + VAT (double our standard carriage-paid order value of £75 + VAT), we are happy to split the delivery into two shipments if some items are needed urgently and others are not immediately available. If you have any questions or need further assistance, feel free to reach out to us via WhatsApp for live support. We’re here to help!

    In Stock Delivery Policy

    Free Next-Day Delivery Over £75 + VAT:
    Orders above £75 + VAT qualify for free next-day delivery via DPD for in-stock items. While we strive for timely dispatch, we recommend placing orders early to avoid potential delays. Once dispatched, unexpected issues may arise despite the courier’s efforts.

    Orders Below £150 + VAT:
    To keep costs manageable, we dispatch your order once all items are ready, including products with longer lead times.

    Need items faster? You can pay for an additional delivery service to receive in-stock items sooner. Simply email us with your order details, and we’ll send you a payment link for the extra delivery cost.

    Orders Above £150 + VAT:
    For larger orders, we can split delivery at no extra cost. In-stock items will be sent immediately, with the remaining items dispatched once available.

    Backorder Delivery Policy

    Items with Lead Times (e.g., 1–3 Working Days):
    This means we need to source the product from our supplier before sending it to you. The estimated dispatch time is displayed on each product page.

    Out of Stock at Supplier:
    If an item is unavailable at the supplier, we will contact you promptly. You’ll have the option to choose an alternative product or request a full refund.

    Didn't find what you're looking for?

    No problem — message us directly on WhatsApp and we’ll help you out.

    We usually respond within minutes during working hours.

    Cookie Preferences
    Our website uses cookies and by using the site you agree to this. To find out more about how we use cookies please view our Privacy Policy.