Phoenix Contact’s Thermal-Magnetic Circuit Breaker Features 8-mm Profile

Phoenix Contact has introduced the PTCB TM, an 8 mm-wide pluggable thermal-magnetic circuit breaker. The circuit breaker integrates overcurrent protection and signaling into a single module while also reducing overall width requirements compared to comparable thermal-magnetic breakers.

Phoenix Contact designed the PTCB TM series for applications with elevated inrush currents. The series operates with nominal current ratings ranging from 0.5 A to 16 A and is available with F2 and M1 trip curves. These features enable the breaker to be used across a range of loads, from sensitive electronic control circuits to motors and transformers that draw higher startup currents.

Phoenix Contact’s PTCB TM pluggable thermal-magnetic circuit breakers are just 8 mm wide. Image used courtesy of Phoenix Contact

Compact Design for Higher Cabinet Density

At just 8 mm wide, Phoenix Contact’s PTCB TM thermal-magnetic circuit breakers are built to increase usable DIN rail space. In control cabinets with limited layout flexibility, reducing breaker width directly affects how many additional components can be installed. Protection and signaling are combined in a single housing, eliminating the need for separate auxiliary signaling modules.

A tilting lever on the circuit breakers provides a clear mechanical indication of the switching state, even when power is removed. This simplifies troubleshooting during commissioning or maintenance. The integrated status signal contact keeps operators informed of the breaker state without adding external hardware.

Tilting levers on the PTCB TM provide operators with a clear visual indication of breaker status. Image used courtesy of Phoenix Contact

Optional current monitoring provides additional visibility into load conditions. The signaling threshold can be adjusted to allow early detection of abnormal current draw before a full trip event occurs. Digital outputs enable connection to a PLC for remote status indication, supporting both local and centralized monitoring strategies.

Trip Performance and Power Supply Coordination

The PTCB TM circuit breakers feature a thermal-magnetic tripping mechanism that effectively manages high inrush currents while providing selective protection within circuits. With the available F2 and M1 trip curves, these circuit breakers offer flexibility for coordinating different circuit types in the same panel.

When paired with Phoenix Contact QUINT POWER power supplies, these breakers can leverage selective fuse breaking technology, as QUINT POWER devices can deliver up to six times the nominal current for short periods. This delivery supports the reliable startup of motors or inductive loads, ensuring that only the affected circuit trips during a fault condition and preserving system availability while maintaining fault isolation.

The PTCB TM paired with Phoenix Contact’s QUINT POWER power supply. Image used courtesy of Phoenix Contact

Bridging and System Integration

The PTCB TM can be directly bridged into Phoenix Contact’s CLIPLINE complete terminal block system, so users don’t have to build protection and potential distribution as separate structures on the rail. This feature keeps the layout consistent and cuts down on jumpers and extra wiring. The series is built for typical industrial cabinet conditions, and the conformal coating on the PCB helps it hold up in environments where dust, humidity, or temperature swings are part of the job.