The Siemens 5TT5030-1 is a SENTRON Insta contactor with 4 normally-open (NO) contacts, rated for 400 V at 25 A. The coil operates on 115 V AC or 110 V DC, making it a straight swap for panels wired with either control voltage. The four NO poles switch resistive or moderate inductive loads — think lighting banks, heater elements, or small motor starters where the contactor is the main power element, not a signal relay. The overall depth is 71 mm, with an installation depth of 64 mm — enough clearance for most standard enclosures, but check the gland plate depth if you're packing a tight panel.
Mounting and thermal notes
IP20 rated, so it's for inside a cabinet — not washdown or outdoor. The spec sheet calls for spacers between units to let heat dissipate; at 2.2 W per pole in hot state, stacking contactors without gaps will derate the current capacity. Plan for at least a few millimeters of air between adjacent devices on the rail. Supplementary devices (auxiliary contact blocks, surge suppressors) can be installed on the side, which is handy if you need to add feedback to a PLC later without rewiring the main poles.