Siemens 5SJ4210-8HG42 Miniature Circuit Breaker

Select this 10A miniature circuit breaker when the circuit requires 10A overcurrent protection. Coordinate that rating with the load requirements and conductor ampacity.

The breaker provides a 2-pole arrangement for a single-phase circuit. Choose it when the circuit requires overcurrent protection on two conductors.

At 240VAC, the breaker has a 14kA interrupting rating. For that application, verify that the available fault current at the installation point does not exceed 14kA.

A D trip curve tolerates higher brief inrush currents before instantaneous tripping than more sensitive curves. Choose it when load startup current calls for that response, while coordinating fault protection with the circuit.

Both the thermal and magnetic trip settings are fixed. The thermal element provides long-time overload protection, while the magnetic element provides instantaneous response to high fault current. Select the required rating and trip curve rather than planning to tune the breaker in the field.

Use copper conductors within the 14-4 AWG wire range. The screw-clamp terminals secure the conductors mechanically. Select conductor size within that range based on circuit ampacity and installation requirements.

The breaker supports surface or DIN rail mounting. Use its 4.92 in height, 3.3 in length and 1.57 in width when planning the physical layout and space for conductor routing.

The voltage ratings are 240VAC, 480Y/277VAC and 125VDC. Select according to the circuit voltage and whether the system is AC or DC. For the 480Y/277VAC rating, use the wye system voltage arrangement when evaluating the application.