The Schneider Electric TeSys B CV1BH1H0ZM522 is a 1-pole contactor rated for 300 A in AC-3 duty at 690 V AC, with a 220 V AC 50 Hz coil. For resistive or heating loads (AC-1), the same pole can handle higher steady-state current, but the AC-3 number is the one that matters when you're driving a motor starter.
Auxiliary contacts and control wiring
Built-in auxiliary contact block carries 2 NO + 2 NC contacts, which covers basic interlocking, status feedback, and holding-circuit wiring without an add-on block. The coil is AC-operated at 220 V 50 Hz — verify your control transformer taps before wiring, because AC coils pull higher inrush on pickup and drop out at a lower voltage than a DC coil would. If the panel runs on 60 Hz, the coil's impedance shifts; the 50 Hz rating is the one to match.
Single-pole format saves rail space compared to a 3-pole block when you only need one switched line — common on single-phase motor circuits, resistive heater banks, or as a line-isolation contactor. The TeSys B range mounts on standard DIN rail; the 300 A rating means the power terminals are sized for larger cable lugs, so plan gland-plate entry and bend radius accordingly. No forced-air cooling required at rated current, but keep adjacent heat-generating devices (transformers, power supplies) a few slot widths away to avoid derating.