The Furnas/Siemens A45-40-00-80 is a 4-pole, non-reversing across-the-line block contactor rated 70 A with a 230-240 V AC coil and no auxiliary contacts. This is a panel-mount power switching device sized for motor and resistive loads up to its 70 A continuous rating — the 4-pole configuration lets it switch three phases plus a neutral or a second load circuit in a single block.
The 70 A rating governs the continuous current the main poles can carry in a standard industrial enclosure at 40 °C ambient — derate for higher panel temperatures or dense ganging. The 230-240 V AC coil (50/60 Hz) means the control circuit must supply that voltage range; a 24 VDC or 120 VAC coil will not pull this contactor in. Non-reversing type: no mechanical interlock for forward-reverse pairs, so if the application needs motor reversing, two of these plus an external interlock are required.
No auxiliary contact block is fitted; if feedback or status signaling is needed, an add-on side-mount aux stack must be ordered separately. The 4-pole layout with AC coil means the coil inrush and hold VA draw should be checked against the control transformer sizing, especially on a shared 240 V control bus.