Shunt Trip Coils

Shunt trip coils are switchgear accessories fitted in or beside a circuit breaker that trigger the tripping mechanism when voltage is applied to their terminals, allowing the breaker to be opened remotely. They are used to trip open type, molded case and miniature circuit breakers remotely with a signal from an emergency stop button, a fire alarm system or a protection relay. The category includes MX shunt trip, MN undervoltage and XF closing coils for Schneider Electric Masterpact NT and NW breakers and shunt trip coils suited to the ABB Tmax T, FORMULA and S800 series; coil voltages such as 100-130 V AC/DC, 200-250 V AC/DC and 380-480 V AC are available. Choose the coil type (shunt trip, undervoltage or closing), the coil voltage and AC/DC type, and the breaker's brand, series and frame size and its fixed or draw-out construction according to your breaker's label. A shunt trip coil trips the breaker when voltage is applied, while an undervoltage coil trips it when the voltage is cut or drops. A shunt trip coil should not be confused with a contactor's spare coil; it fits only the breaker series it belongs to.

Products

How to choose Shunt Trip Coils

Shunt trip coils are switchgear accessories fitted in or beside a circuit breaker that trigger the tripping mechanism when voltage is applied to their terminals, allowing the breaker to be opened remotely. They are used to trip open type, molded case and miniature circuit breakers remotely with a signal from an emergency stop button, a fire alarm system or a protection relay.

  • Separate overcurrent/leakage protection, motor starting and local isolation requirements.
  • Select rated current, pole count and breaking capacity (kA) from the installation calculation.
  • Match coil voltage, auxiliary contacts and tripping curve to the control circuit and load type.

Frequently asked questions

What is Shunt Trip Coils and where is it used?

Shunt trip coils are switchgear accessories fitted in or beside a circuit breaker that trigger the tripping mechanism when voltage is applied to their terminals, allowing the breaker to be opened remotely. They are used to trip open type, molded case and miniature circuit breakers remotely with a signal from an emergency stop button, a fire alarm system or a protection relay.

What should I compare when choosing Shunt Trip Coils?

Choose the coil type (shunt trip, undervoltage or closing), the coil voltage and AC/DC type, and the breaker's brand, series and frame size and its fixed or draw-out construction according to your breaker's label.

Where can I find technical details for Shunt Trip Coils products?

A shunt trip coil should not be confused with a contactor's spare coil; it fits only the breaker series it belongs to.

Shunt Trip Coils Selection Guide: Technical Criteria and Engineering Practice