CNC NV822478 Automatic Transfer Switch 4-pole 220 V 100 A

Automatic transfer switch CNC NV822478 is a 4-pole device rated for AC 220 V and 100 A designed to switch power automatically between two sources. It provides fast transfer times under 50 ms, supports manual operation, and conforms to IEC 60947-6-1 requirements for low-voltage switchgear and controlgear. The compact unit mounts on a DIN rail and is intended for situations where uninterrupted power is required, such as mains-to-generator transfer in residential or light commercial installations.

Advantages

The CNC NV822478 offers compact dimensions (100 x 142 x 76 mm), reliable automatic and manual switching, and short contact and operating transfer times (<50 ms). It features a 4-pole contact arrangement, insulation voltage up to AC 690 V, rated voltage AC 400 V, and is rated for a conditional short-circuit current of 50 kA. Installation is simplified with DIN-rail mounting, and the unit meets relevant IEC standards for low-voltage applications.

Suitable for

• Automatic mains-to-generator transfer in homes
• Backup power systems for small commercial premises
• Applications requiring uninterrupted power or fast source transfer

Key specifications

• Model: CNC NV822478
• Poles: 4
• Main voltage (control): AC 220 V
• Rated current: 100 A
• Frequency: 50/60 Hz
• Insulation voltage (Ui): AC 690 V
• Rated voltage (Ue): AC 400 V
• Rated conditional short-circuit current: 50 kA
• SCPD (fuse): RT16-00-63A
• Rated impulse withstand voltage: 8 kV
• Contact transfer time / Operating transfer time / Return transfer time / Off-time: <50 ms
• Installation: DIN-rail mounting
• Dimensions: 100 x 142 x 76 mm
• Mechanical life: 5000 operations
• Electrical life: 2000 operations
• Weight: 656 g
• Warranty: 24 months

How to use

Mount the automatic transfer switch on a standard DIN rail in a suitably rated distribution enclosure, connect the two power sources and the load according to the wiring diagram, and supply the control/main voltage (AC 220 V) to the main and auxiliary circuits. After correct wiring and verification, the unit will automatically transfer the load between sources when needed; manual operation is also available for testing or maintenance. Observe all local electrical codes and de-energize circuits before making connections.

Recommendations

Use appropriate overcurrent protection (fuses or breakers) sized according to the SCPD specification (RT16-00-63A) and the installation’s conductor ratings. Verify that the short-circuit rating and insulation levels are compatible with the installation. Schedule routine inspections and functional tests to confirm transfer operation and prolong service life.