Siemens 3VU1300-1MH00 Motor Protection Circuit Breaker – 3VU Series

Siemens 3VU1300-1MH00 — Thermal-Magnetic Motor Protection Circuit Breaker for Industrial Control Circuits

The Siemens 3VU1300-1MH00 is a 3-pole thermal-magnetic motor protection circuit breaker (MPCB) belonging to the 3VU product family. It is designed to provide coordinated overload and short-circuit protection for three-phase AC motors in low-voltage industrial control systems. The device integrates a bimetallic thermal trip element for sustained overload detection and a magnetic instantaneous trip element for fault-current interruption, combining both protection functions within a single compact housing rated for DIN rail or panel-mount installation.

In a motor control circuit, the 3VU1300-1MH00 occupies the upstream protective position between the supply busbar and the motor contactor. Its primary function is to interrupt the supply path before thermal damage accumulates in the motor winding insulation or before a bolted fault propagates upstream to the distribution board. The device achieves this through a calibrated bimetallic deflection mechanism whose trip threshold is factory-set to the rated current band of the 1MH00 variant, eliminating the need for external overload relays in standard direct-on-line (DOL) starter configurations.

The 3VU series was developed to satisfy IEC 60947-4-1 coordination requirements for motor starters, meaning the breaker’s let-through energy (I²t) characteristic is matched to the thermal withstand capability of Siemens 3RT-series contactors. This coordination eliminates contact welding under short-circuit conditions and ensures the contactor remains serviceable after a fault event — a critical factor in continuous-process industries where unplanned downtime carries measurable financial consequence.

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Technical Parameters

Hardware Logical Analysis

Thermal Trip Element — Bimetallic Deflection Mechanics: The overload detection in the 3VU1300-1MH00 relies on a bimetallic strip carrying the full motor current. As current exceeds the rated threshold, resistive heating causes differential thermal expansion between the two bonded metal layers, producing a mechanical deflection proportional to the I²t integral. When deflection reaches the calibrated trip point, it releases the latch mechanism and opens all three poles simultaneously. The thermal memory effect means the bimetallic element retains heat after a trip, enforcing a mandatory cooling period before reset — this prevents repeated hot-starts that would otherwise degrade motor winding insulation through cumulative thermal stress.

Magnetic Instantaneous Trip Element — Electromagnetic Plunger Design: For short-circuit conditions, the 3VU1300-1MH00 employs a solenoid-type electromagnetic trip element. When fault current exceeds the instantaneous trip threshold (typically 12× to 14× rated current for motor protection devices), the magnetic field generated by the fault current actuates a plunger that directly releases the trip latch, bypassing the slower thermal mechanism entirely. Contact separation occurs within milliseconds, limiting arc energy and protecting downstream wiring insulation from thermal damage.

EMC Design Considerations: The 3VU series housing is constructed from glass-fiber reinforced thermoplastic with arc-quenching chambers that confine the ionized gas column generated during contact separation. The arc chute geometry forces the arc to elongate and cool rapidly, reducing the duration of the high-frequency transient that accompanies contact interruption. This limits conducted emissions on the supply network — a relevant consideration in installations where variable-frequency drives or sensitive measurement instrumentation share the same distribution panel.

Mechanical Endurance and Contact Material: The contact system uses silver-based alloy contacts with a surface geometry optimized for the current range of the 3VU1300 frame. The contact pressure spring maintains consistent contact force across the rated mechanical endurance cycle count, preventing resistance creep at the contact interface that would otherwise generate localized heating and accelerate contact erosion.

Trip-Free Mechanism: The 3VU1300-1MH00 incorporates a trip-free design: the contacts cannot be held closed against a persistent fault by manually forcing the operating handle. If a fault condition is present, the trip mechanism overrides the handle position and opens the contacts regardless of operator input. This is a fundamental safety requirement under IEC 60947-2 for devices used in motor protection applications.

System Integration Benefits

• Type 2 Coordination with 3RT Contactors: The 3VU1300-1MH00 is characterized for Type 2 coordination per IEC 60947-4-1 when paired with Siemens 3RT-series contactors. Under this coordination class, neither the breaker nor the contactor sustains damage that prevents continued operation after a short-circuit event, eliminating the need for contactor replacement following a fault — a direct reduction in maintenance labor and spare-parts inventory.
• Elimination of Separate Overload Relay: By integrating thermal overload protection within the breaker body, the 3VU1300-1MH00 removes the need for a discrete 3RU-series overload relay in standard DOL starter assemblies. This reduces the component count, wiring terminations, and panel depth required for each motor circuit.
• Deterministic Trip Response: The magnetic instantaneous trip element provides a fixed, calibrated response time independent of ambient temperature variation, ensuring consistent fault clearance timing across the full operating temperature range of -25 °C to +60 °C.
• DIN Rail Standardization: Compliance with EN 60715 35 mm DIN rail mounting allows the 3VU1300-1MH00 to be integrated into standard modular enclosures alongside Siemens SITOP power supplies, 3RT contactors, and S7-series PLC I/O modules without requiring custom mounting hardware.
• Auxiliary Contact Compatibility: The 3VU series supports snap-on auxiliary contact blocks that provide potential-free signaling contacts for PLC digital inputs, enabling the control system to detect breaker trip status without additional current transformers or relay interposing circuits.
• Upstream Selectivity: The 3VU1300-1MH00’s time-current characteristic is designed to be selectively coordinated with upstream molded-case circuit breakers (MCCBs) in the distribution board, ensuring that a motor fault trips only the branch breaker and does not cascade to the feeder protection device.
• Reduced Commissioning Time: Factory-calibrated trip settings eliminate field adjustment of overload relay dials, reducing commissioning time per motor circuit and removing a source of human error in trip threshold configuration.
• Compliance with Machine Directive: The device’s conformity to IEC/EN 60947-2 and IEC/EN 60947-4-1 supports CE marking of the complete machine or control panel under the EU Machinery Directive 2006/42/EC, simplifying the technical documentation package for OEM machine builders exporting to European markets.

Quality Assurance & Global Logistics

Every Siemens 3VU1300-1MH00 unit supplied through siemensplc.com is sourced as genuine Siemens original equipment. Units are stored in a climate-controlled warehouse in Xiamen, China, maintaining ambient conditions within the manufacturer’s specified storage temperature range of -40 °C to +80 °C. Prior to dispatch, each unit undergoes a multi-point inspection covering packaging seal integrity, label authenticity verification against Siemens product identification standards, and physical condition assessment.

Shipments from Xiamen are processed through established express freight channels including DHL Express, FedEx International Priority, and UPS Worldwide Express. Transit times to major industrial hubs in Southeast Asia, the Middle East, and Europe typically range from 3 to 7 business days under standard express service. For time-critical plant maintenance scenarios, same-day dispatch is available for orders confirmed before 14:00 CST.

Full commercial documentation is provided with each shipment: commercial invoice, packing list, and certificate of origin. For customers requiring import compliance support, HS code 8536.20 (automatic circuit breakers for voltage not exceeding 1,000 V) applies to this product category. Siemens certificates of conformity and factory test reports are available upon request for OEM integrators and EPC contractors requiring traceability documentation for project quality records.

A 12-month warranty from the date of dispatch covers manufacturing defects. Warranty claims are processed through direct communication with our technical team, with replacement units dispatched upon confirmation of the defect. The warranty does not cover damage resulting from installation errors, operation outside rated parameters, or unauthorized modification.

Contact Information

Email: [email protected]
WhatsApp: +86 18359268345
Web: siemensplc.com
Location: Xiamen, China
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