160 A MCCB for line protection — what the ratings mean
The Siemens 3VA1116-3EE32-0AA0 is a 3-pole SENTRON molded case circuit breaker rated at 160 A continuously at 40 °C ambient, with no derating needed up to 50 °C — same 160 A holds at 45 °C and 50 °C. Above that, it steps down to 158 A at 55 °C, 155 A at 60 °C, 153 A at 65 °C, and 150 A at 70 °C. That thermal curve means this breaker can sit in a warm panel without losing much headroom; at 70 °C it still carries 150 A, which is a 6% drop from the 40 °C rating. The TM220 overcurrent release combines a thermal bimetal for overload protection and a magnetic coil for short-circuit response — standard thermal-magnetic, no electronic trip unit, so no auxiliary power needed for the trip function. Breaking capacity is 75.6 kA at 240 V, 52.5 kA at 415 V, 32 kA at 440 V, and 11.9 kA at both 500 V and 690 V. These are the maximum fault currents the breaker can safely interrupt at each voltage level. For a 400 V distribution panel, the 52.5 kA figure gives solid headroom against most utility fault levels; at 690 V the 11.9 kA rating still covers typical industrial supply points. The insulation voltage is rated at 800 V, so the breaker can be used in 690 V systems without exceeding its dielectric limits. Measures 70 mm deep, 76.2 mm wide, and 130 mm high. Front protection is IP40.