The Siemens 5SU1353-6KV32 is an FI/LS protector combining Type A residual current protection and a B-curve miniature circuit breaker in a single 1+N-pole module, rated 32 A with 30 mA sensitivity and 4.5 kA breaking capacity.
What the ratings mean for fit
Type A detection means it catches pulsating DC residual currents from rectified loads (VFDs, switched-mode supplies, LED drivers) — not just sinusoidal AC faults — so it's specified for circuits feeding modern electronics where standard AC-only RCDs would blind-trip or fail to trip. 30 mA IΔn is the standard personnel-protection threshold per IEC 60364; 4.5 kA breaking capacity covers residential and light commercial distribution boards fed by a transformer rated up to about 250 kVA. The B-curve (3-5 In magnetic trip) suits resistive and general-purpose loads with low inrush — lighting, socket circuits, small appliances. At 70 mm deep (D=70mm), it fits standard DIN-rail distribution boards without protruding past the enclosure cover — relevant when retrofitting into existing panels where wiring duct or gland-plate clearance is tight.
Lifecycle and sourcing reality
This part is sourced and quoted to order against an RFQ through independent distribution channels. Availability and current pricing are confirmed at quote time.
Panel integration note
Snap-on DIN rail mounting, 1+N pole width (two modules wide). Neutral on the right, line on the left — verify busbar alignment if replacing a standard MCB-only position in an existing distribution board.