Square D PJA36120U43AYP PowerPact P MCCB Unit

Module Feature

PJA36120U43AYP is a PowerPact P frame molded case circuit breaker from Square D. It adopts I-Line plug-in connection structure, compatible with Square D I-Line bus system. Micrologic 5.0A trip unit supports adjustable long-time overload, short-time delay and instantaneous short-circuit LSI protection. 3-pole 1200A frame rating, 80% continuous rating design. It supports field-installable accessories such as auxiliary contact, alarm switch, shunt trip and undervoltage release, and can be equipped with communication module for power monitoring network. Widely stocked as spare for factory low voltage switchboard, data center distribution cabinet and commercial power distribution panel.

Working principle

Built-in current transformers sample three-phase current and send signals to Micrologic 5.0A trip controller. The processor compares real-time current with preset protection thresholds. Overload triggers inverse time delay trip, short-time fault triggers short-delay trip, high-level short-circuit triggers instantaneous trip to isolate fault circuit. Auxiliary and alarm contacts output breaker ON/OFF and trip status signals, and protection data can be uploaded to power SCADA system via communication module.

Onboard componentsCurrent transformer group, Micrologic 5.0A electronic trip unit, main contact assembly, arc quenching chamber, spring operating mechanism, I-Line line side connector, load side terminal lugs, operation handle and reinforced insulated housing.

LED indicatorsFront mechanical markers show ON, OFF and tripped position; trip unit LCD and LEDs display measured current, alarm and fault codes.

Hardware self‑diagnosisTrip unit monitors CT signal integrity, internal power supply and thermal status. LSI protection thresholds and alarm parameters can be adjusted locally or remotely.

Programming softwareSchneider EcoStruxure Power Commission, used for trip parameter configuration, fault record query and power data logging.

Electrical & Process Parameters

Model: PJA36120U43AYP Brand: Square D (Schneider Electric) Device type: Molded case circuit breaker Frame rating: 1200 A Pole: 3P Rated voltage: 600 VAC Icu: 25 kA @600VAC Trip unit: Micrologic 5.0A (LSI) Mounting: I-Line plug-in Function: Overload, short-time and short-circuit protection for low voltage distribution feeders

Mechanical & Structure

Mounting: I-Line plug-in mounting inside LV switchgear Protection class: IP40 front panel Housing: Reinforced insulated plastic enclosure

Environmental

Operating temperature: -25℃ ~ +60℃ Storage temperature: -40℃ ~ +85℃ Ambient humidity: 5~95% non‑condensing

Certification: CE, UL489, CSA Status: Original Square D electrical distribution spare

Installation

Cut off upstream power supply before replacement. Align breaker with I-Line bus and lock in connected position, tighten load side lug terminals, wire auxiliary, alarm and communication accessories if fitted, configure Micrologic protection settings, test close, open and trip action after commissioning.

Interface

I-Line plug-in line terminals, load side lug terminals, auxiliary/alarm contact terminals, shunt / undervoltage trip terminals, communication module port.

Diagnostic

Overload trip: Continuous load current exceeds long delay setting. Short-time trip: Downstream short-circuit fault within short delay window. Communication failure: Trip unit power loss or communication wiring loose.

Product Brief

PJA36120U43AYP breaker, Square D PowerPact P 3P 1200A I-Line plug-in MCCB spare for industrial low voltage feeder protection replacement.