What this part is and what it does
The Siemens 3VA1110-1AA42-0AG0 is a SENTRON 3VA1 switch disconnector in an MCCB-style housing, rated for 100 A continuous current (Iu) on a 4-pole IEC frame 160 footprint. It provides visible isolation and load-break capability without integral overload or short-circuit protection — it is a disconnector, not a circuit breaker. The front terminals accept busbar connections, and the unit ships with a nut keeper kit for panel mounting. Rated operational voltage reaches 690 V AC 50/60 Hz and 600 V DC, with an insulation voltage (Ui) of 800 V.
Key ratings and what they mean for fit
The 100 A rated continuous current (Iu) is the maximum uninterrupted load this disconnector can carry in free air — it is sized for a 100 A feeder or branch circuit, not for motor starting duty. The 4-pole configuration switches all three phases plus neutral, common for TN or TT systems where neutral isolation is required. With a short-time withstand of 2 kA for 1 s (and the same for 0.5 s), the disconnector can pass fault current up to that level without welding closed, but it relies on an upstream protective device to clear the fault — coordination with the upstream breaker or fuse is mandatory.
Auxiliary contacts and integration
The disconnector comes with one auxiliary switch (HP) and one trip alarm switch (HP), providing two CO contacts total for status feedback to a PLC or indication lamp. The auxiliary release is omitted — no shunt trip or undervoltage release is fitted, so remote tripping requires an external motor drive (optional, per the product extension listing). The IP40 front protection means it is suitable for enclosed panel mounting where no water jets or dust ingress are expected; the rear and sides are not rated for open mounting.