Siemens 3VA4120-5ED34-0AA0 Molded Case Circuit Breaker

This is a 20A, three-pole molded case circuit breaker for three-phase circuits. Select it when the circuit requires a 20A breaker and three-pole protection, with voltage and interrupting ratings appropriate for the installation.

The voltage ratings are 240VAC, 480VAC, 480Y/277VAC, 600Y/347VAC and 250VDC. The slash-rated AC values apply to grounded-wye systems. Match both the circuit voltage and system configuration when selecting the breaker.

The interrupting ratings are 85kA at 240VAC, 35kA at 480Y/277VAC, 18kA at 600Y/347VAC and 85kA at 250VDC. Select an interrupting rating at the applicable voltage that meets or exceeds the available fault current at the installation point.

The lug terminals accept 14-8 AWG copper or aluminum conductors. Choose a conductor within that range that also satisfies the circuit's ampacity and installation requirements; the terminal range alone does not determine conductor sizing.

This breaker uses bolt-on mounting and measures 5.09 in high, 3.00 in wide and 2.96 in deep. Use those dimensions for the breaker body's installation layout and plan for a bolted mounting arrangement.

Yes. Its reverse-feed feature permits incoming power to enter through the load-side terminals. This allows the feed direction to follow the installation's conductor routing.

Current-limiting operation reduces the peak current and energy let through during faults within its current-limiting operating range. This helps reduce fault stress on downstream conductors and equipment while the breaker interrupts the fault.

The breaker is HACR rated for heating, air-conditioning and refrigeration applications, and HID rated for high-intensity discharge lighting applications. Use these application ratings along with the circuit's current, voltage and interrupting requirements when selecting it.

The temperature rating is -25C to 70C. Compare the expected temperature at the breaker's installation location with this range when planning its operating environment.

The thermal and magnetic trip settings are fixed. Thermal-magnetic operation provides long-time overload protection and instantaneous short-circuit protection, so selection should account for fixed trip operation rather than field-adjustable settings.