1. General Specifications

• Brand & Model: Siemens 3VL9440-7DC30
• Product Category: Auxiliary Contact Block (for molded case circuit breakers)
• Compatibility: Exclusive to Siemens 3VL series MCCBs (rated current: 100A–1600A; frame sizes: 3VL1, 3VL2, 3VL3, 3VL4)
• Certifications: IEC 60947-2, UL 489, CSA C22.2 No. 5, CE, KEMA-KEUR (compliant with global low-voltage electrical safety standards)
• Primary Function: Adds 2 normally open (NO) auxiliary contacts to 3VL MCCBs, transmitting the breaker’s "closed/opened" status to external control systems (e.g., PLCs, HMIs) or triggering auxiliary devices (e.g., alarms, indicators).

2. Electrical Characteristics

Contact Parameters

• Number of Contacts: 2 poles (2 x Normally Open / NO)
• Rated Voltage (Ue): 690 V AC (max) / 250 V DC (max)
• Rated Current (Ie): 10 A AC (at cosφ = 0.8) / 1 A DC (at τ = 5 ms)
• Rated Making Current (Icm): 100 A AC / 10 A DC
• Rated Breaking Current (Icb): 50 A AC / 5 A DC
• Contact Material: Silver-nickel (AgNi) alloy – ensures low contact resistance and high arc-resistant performance for long-term reliability
• Contact Resistance: ≤ 50 mΩ (initial, measured at 1 A DC)

Dielectric & Insulation Performance

• Dielectric Strength: 2.5 kV AC (50 Hz, 1 min) between contacts and ground; 1.8 kV AC between adjacent contacts
• Insulation Resistance: ≥ 100 MΩ (measured at 500 V DC, 20°C, 50% RH)
• Pollution Degree: PD2 (suitable for industrial environments with low dust and condensation)

3. Physical & Mechanical Characteristics

• Dimensions (W x H x D): 22 mm × 65 mm × 48 mm (compact design for easy mounting on 3VL MCCB side panels)
• Weight: ~55 g (lightweight, no impact on MCCB installation or operation)
• Mounting Type: Snap-on mechanical mounting – directly attaches to the side of 3VL series MCCBs (no additional tools required for installation)
• Enclosure Material: Thermoplastic (PA66-GF30) – flame-retardant (UL94 V-0), heat-resistant, and resistant to industrial oils/chemicals
• Operating Mechanism: Mechanical linkage with 3VL MCCB’s operating shaft – contact state synchronizes with the breaker’s main contact position (no delay)

4. Environmental Specifications

• Operating Temperature Range: -25°C to +70°C (suitable for most industrial indoor environments, e.g., switchgear cabinets, control rooms)
• Storage Temperature Range: -40°C to +85°C
• Humidity: 5%–95% RH (non-condensing; no performance degradation in high-moisture areas like water treatment plants)
• Vibration Resistance: 10–500 Hz, 10 m/s² (compliant with IEC 60068-2-6)
• Shock Resistance: 30 m/s² (11 ms half-sine wave; compliant with IEC 60068-2-27)

5. Functional Features

• Synchronized Status Transmission: Auxiliary contacts open/close simultaneously with the MCCB’s main contacts, ensuring accurate real-time status feedback (critical for interlocking or safety circuits).
• High Mechanical Life: ≥ 100,000 operating cycles (meets IEC 60947-2 requirements) – suitable for frequent breaker operations.
• Low Maintenance: Sealed contact design prevents dust ingress; no periodic cleaning or adjustment needed.
• Safety Interlocking Compatibility: Can be used to interlock multiple 3VL MCCBs (e.g., prevent simultaneous closure of two breakers in a redundant power system) or lock out non-essential loads during fault conditions.

6. Applications

• Industrial Plants: Monitoring breaker status in motor control centers (MCCs), conveyor systems, or manufacturing equipment power circuits.
• Commercial Buildings: Integrating with building management systems (BMS) to track power distribution in HVAC, lighting, or elevator circuits.
• Data Centers: Providing status signals for UPS (uninterruptible power supply) backup circuits or critical server power feeds.
• Renewable Energy: Monitoring breaker operation in solar inverter systems or wind turbine power distribution cabinets.

7. Integration & Compatibility

• MCCB Compatibility: Works with all 3VL series MCCBs, including:
  • Frame size 3VL1 (100A–250A)
  • Frame size 3VL2 (250A–400A)
  • Frame size 3VL3 (400A–800A)
  • Frame size 3VL4 (800A–1600A)
• Control System Integration: Contacts can be wired to PLC inputs (e.g., Siemens S7 series), HMIs, or alarm relays via 1.5–2.5 mm² copper wire.
• Wiring Terminals: Screw-type terminals (M3.5) – accept wire cross-sections: 0.5–2.5 mm² (solid) / 0.5–1.5 mm² (stranded); torque rating: 0.8 N·m.

8. Availability & Support

• Supply Channels: Siemens authorized distributors (e.g., RS Components, Allied Electronics, Siemens Industrial Supply) – available as standalone units or bundled with 3VL MCCBs.
• Warranty: 2 years (standard Siemens industrial component warranty; extends to 5 years if installed by Siemens-certified technicians).
• Technical Support: Siemens provides 24/7 support via the Siemens Support Portal, including installation guides, CAD drawings, and compatibility check tools.
• Replacement Parts: Directly interchangeable with older Siemens auxiliary contact blocks (e.g., 3VL9440-7DC20) for retrofits.

Important Notes

• Polarity: No polarity required for AC circuits; for DC circuits, follow Siemens wiring guidelines to avoid contact arcing.
• Mounting Orientation: Must be installed on the designated side panel of 3VL MCCBs (labeled "Auxiliary Contact" on the breaker frame) – incorrect mounting may damage the linkage.
• Documentation: For detailed wiring diagrams, compatibility lists, and installation steps, refer to Siemens’ 3VL Series Molded Case Circuit Breakers – Auxiliary Contacts Technical Datasheet (Document No. 10947794).