Motor circuit breaker MPX3 32S 0.1-0.16A standard breaking capacity 417300

Construction and purpose of the device

The MPX3 32S motor protector is a compact protective device from the X3 family, designed to protect three-phase electric motors in industrial and semi-industrial installations. The device is mounted on a 35 mm DIN rail and occupies a width of only 45 mm (2.5 modules), allowing for space savings in distribution boards.

It features a thermomagnetic tripping method - the thermal part provides adjustable overload protection, while the magnetic part ensures immediate disconnection during short circuits. The operating thresholds are precisely selected: the thermal protection can be set in the range of 0.1-0.16 A, allowing it to be matched to the rated current of the protected motor. The magnetic threshold is fixed at 13 × Ie (setting current), which in this case equals 2.1 A - guaranteeing a rapid disconnection in the event of a short circuit without the risk of accidental tripping during startup.

The enclosure provides an IP20 protection rating, and the control lever allows for manual switching on and off of the device without additional tools.

Integrated functions and expansion capabilities

The manufacturer has equipped the switch with a range of additional standard functions:

• Auxiliary contact - integrated into the housing, it enables the transmission of device status information to control or signaling systems.
• Under-voltage release - automatically disconnects the circuit if the voltage drops below a set threshold, protecting the motor from unfavorable operating conditions caused by phase loss or voltage asymmetry.
• Test function - allows for checking the operation of the tripping mechanism without the need to induce an actual overload.

For installation expansion, dedicated peigne'y zasilające (comb busbars/kombi terminals) are provided - three-phase busbars for the group connection of devices in the distribution board.

Operating parameters and exploitation conditions

The device operates at a working voltage from 220 to 690 V AC, which covers typical 230/400 V industrial networks as well as installations with higher requirements. A key parameter is the rated short-circuit capacity Icu = 100 kA at 400 V AC - a very high value for a compact switch of this class, ensuring safe operating conditions even in large installations with high short-circuit currents.

Mechanical parameters confirm the durability of the construction:

Parameter	Value
Mechanical endurance	100 000 switching cycles
Electrical endurance	100 000 cycles
Maximum operations/h	25
Operating temperature	-20°C to +60°C

The rated three-phase motor power at 400 V for this caliber is 0.02 kW - therefore, the device is dedicated to protecting small auxiliary motors, fans, pumps, and similar loads with low current consumption.

Standards and approvals

The MPX3 32S switch complies with the requirements of international standards:

• IEC 60947-1 - general rules for low-voltage switchgear and controlgear,
• IEC 60947-2 - requirements for circuit breakers,
• IEC 60947-4 - standard for motor starter switchgear and controlgear (category AC-3).

The top and bottom terminals accommodate both rigid wires (1×10 mm² / 2×6 mm²) and flexible wires without ferrules (1×6 mm² / 2×4 mm²) - wiring flexibility facilitates installation in various distribution board configurations.