What it is — and what the ratings mean for your panel
The Siemens 3VA2225-5JQ42-0CH0 is a 4-pole IEC molded case circuit breaker on the 250 A frame, fitted with an ETU560 electronic trip unit providing LSIG protection — long-time, short-time, instantaneous, and ground-fault. The breaking capacity class M delivers Icu=55kA at 415 V, which means it can safely interrupt a fault current up to 55 kA without welding its contacts or rupturing the arc chamber. That class M rating puts it in the middle of the 3VA2 range, sized for industrial distribution panels where the available fault current sits around 40–50 kA and you need selectivity headroom downstream.
Trip unit and protection profile
The ETU560 is a microprocessor-based trip unit with LSIG functions. Overload protection (Ir) is adjustable from 100 A to 250 A, so you dial in the continuous current to match the cable or busbar rating — not just the breaker frame. Short-time pickup (Isd) spans 0.6 to 10 times In, and instantaneous pickup (Ii) runs 1.5 to 10 times In. Ground-fault protection (Ig) is adjustable from 0.2 to 1 times In with a time delay tg of 0.05 to 0.8 seconds, and it can be switched off entirely if the installation uses a separate GFCI. The neutral conductor protection is also adjustable (OFF, up to 100% of In). That level of adjustability means one breaker covers a wide range of feeder and main applications — you set the taps at commissioning, not at ordering.
Integrated accessories — undervoltage release and auxiliary switches
This order code comes pre-fitted with an undervoltage release rated 120–127 V AC 50/60 Hz, plus two auxiliary switch changeover contacts (H) and one trip alarm switch changeover contact. The undervoltage release trips the breaker when supply voltage drops below about 70% of rated — standard for safety circuits where you want the breaker to open on loss of control power. The auxiliary switches report the breaker position (open/closed) and the trip alarm signals a fault trip, not a manual open. These are wired into the control circuit, not the power path, so they feed status to a PLC or annunciator panel.
Mounting and panel integration
The 3VA2 frame 250 mounts with four screws onto a mounting plate or into a switchboard — it is not a DIN-rail snap-on breaker. The nut keeper kit mentioned in the description holds the mounting nuts captive, which saves time when you are assembling the breaker into a panel with limited rear access. Plan for the 4-pole footprint: it occupies roughly 280 mm width on the mounting plate, and the line and load lugs accept copper or aluminum conductors sized for 250 A continuous. The undervoltage release coil draws continuously when energized; factor that into the control transformer sizing if you are feeding multiple releases from one source.