Its headline number is the interrupting capacity: 187 kA at 240 V AC, dropping to 121 kA at 415 V, 75.6 kA at 440 V, and holding at 17 kA at both 500 V and 690 V. That curve tells you the breaker is built for high-fault locations — main distribution boards, transformer secondaries, or industrial feeds where prospective short-circuit current can exceed 100 kA. The 20 A rating holds flat from 40 °C through 55 °C, then derates to 19 A at 60 °C through 70 °C. In a warm enclosure — say 55 °C ambient — you still get the full 20 A; above that, budget the 1 A derate.
Panel fit and footprint
The 3VA1120-5EF36-0JH0 measures 76.2 mm wide, 130 mm tall, and 70 mm deep. If you are replacing a unit in an existing panel, check the busbar stack height; the supplied basic switch is order code 3VA11205EF360AA0, which is the internal mechanism — the complete breaker ships as the -0JH0 variant with the shunt trip and aux switches pre-installed.