What's on the nameplate
The 3VA1220-6EF42-0AA0-ZD00: This is a Siemens 3VA1 IEC frame 250 molded-case circuit breaker in the H breaking capacity class — meaning it can interrupt 70 kA at 415 V without welding or venting. That's the Icu rating, and it's the number that governs fault-clearing capability for line-side protection on a 400 V distribution board. Four-pole, with the neutral unprotected (no integral neutral release). The TM240 trip unit gives you thermal-magnetic overload protection adjustable from 140 A to 200 A, and short-circuit pickup adjustable 5 to 10 times In (so 1000 A to 2000 A at the 200 A setting). The suffix ZD00 flags a nut keeper kit and a DC Power OEM build origin in China — same Siemens 3VA platform, just a specific factory configuration.
What the ratings mean for fit
The 70 kA Icu @ 415 V puts this in the H class — it's sized for high-fault locations like a main distribution board or a large motor control center where the prospective short-circuit current is above 50 kA. The 200 A frame with a TM240 trip means it's a line-protection breaker, not a motor-protective device (no electronic overload curve). The adjustable Ir (140–200 A) lets you match it to a downstream transformer or bus rating without swapping the breaker body. The Ii range of 5–10 x In gives you selectivity headroom against downstream branch breakers — set it at 10x (2000 A) if you need to coordinate with 50 A or 63 A feeders. The unprotected neutral means you need a separate neutral disconnect or a 4-pole breaker with a neutral release if the system requires neutral isolation.
