What it is and what it does
The Siemens 3VA1063-4ED42-0CA0 is a SENTRON molded case circuit breaker (MCCB) designed for line protection in distribution panels. It carries a 63 A continuous rating at 40 °C ambient — that's the current it handles without nuisance tripping in a typical 40 °C panel environment. The 4-pole configuration (three phases plus neutral) makes it the right choice for three-phase four-wire systems where you need neutral protection. The TM210 overcurrent release combines a thermal element for overload protection and a magnetic element for short-circuit protection, tuned to a fixed 10× I_n magnetic trip. No communication module, no ground-fault monitoring — this is a straight line-protection breaker, not a multifunction device.
Breaking capacity — what those numbers mean for your fault level
The interrupting rating tells you the maximum fault current this MCCB can safely clear at a given voltage. At 240 V it's rated for 121 kA — that's a very high capacity, typical for a large-frame MCCB used near a transformer secondary. At 415 V it drops to 75.6 kA, at 440 V to 52.5 kA, and at 500 V and 690 V it holds at 11.9 kA. The steep drop above 440 V is characteristic of this class: the arc becomes harder to extinguish as voltage rises, so the breaker's ability to interrupt falls off. If your available fault current at 690 V exceeds 11.9 kA, this breaker won't coordinate — you'd need a higher-rated frame.
Thermal derating and panel integration
The 63 A rating holds flat from 40 °C to 50 °C. Above that it begins to derate: 62 A at 55 °C, 61 A at 60 °C, 60 A at 65 °C, and 58 A at 70 °C. That 8 % drop from 40 °C to 70 °C is the thermal element responding to higher internal temperature — if your panel runs hot, you need to account for that when sizing the load. The breaker measures 130 mm high, 101.6 mm wide, and 70 mm deep, which fits standard SENTRON 4-pole MCCB mounting footprints. Maximum power loss is 19.8 W — that's the heat dissipated at rated current. In a sealed, high-density panel, that heat has to be managed; it's not trivial if you're stacking multiple breakers in a small enclosure.
Undervoltage release and auxiliary release
This unit includes an undervoltage release (UVR) as the auxiliary release. The UVR trips the breaker when the supply voltage drops below a threshold — useful for preventing motor re-acceleration after a voltage sag or for emergency stop circuits that rely on loss of control power. The UVR is wired separately from the main power path; verify the control voltage rating matches your panel's auxiliary supply.