What this 3VA1 breaker is and what the ratings mean
The Siemens 3VA1163-5MH36-0AB0 is a 3-pole IEC frame 160 molded case circuit breaker (MCCB) rated at 63 A continuous current, with a breaking capacity class M delivering Icu = 55 kA at 415 V AC. That 55 kA rating means it can safely interrupt a fault current up to that level without welding its contacts or rupturing the case — critical for high-fault installations like transformer secondaries or large motor control centers where available fault current can exceed 25 kA. This variant is configured for starter protection with a TM120M thermal-magnetic trip unit. The thermal element is sized for motor starting inrush (the 'M' designation), so it won't nuisance-trip on a 6x locked-rotor current during a start sequence. The magnetic short-circuit pickup is adjustable from 5 to 15 times In (315 A to 945 A), letting you coordinate with downstream contactors and overload relays. Note: this breaker provides short-circuit protection only — there is no integral overload protection, so a separate overload relay (e.g., Siemens 3RU2) must be wired downstream for motor thermal protection.
Panel integration and wiring notes
This breaker mounts on a DIN rail or can be screw-fixed to a backplate in a standard IEC enclosure. The clamp-type terminals accept copper or aluminum conductors — strip length and torque values follow the manufacturer's published tightening schedule for the 160 A frame. Two factory-installed auxiliary switches (HP type) are included for remote status indication; they share the breaker's operating mechanism and require no separate power supply.