The higher IEC figure gives the buyer headroom when the part is specified into an industrial SCCR study — the 15 kA value is the one that governs coordination in a panel with upstream fuses or a moulded-case breaker. Voltage rating is 400 V AC and 60 V DC, with an insulation voltage (Ui) of 440 V AC. The 60 V DC limit means this pole is not suitable for common 110 V DC control circuits; for DC applications above 60 V you would step to a 2-pole series connection or a different MCB family.
Depth is 70 mm, matching the 5SJ4 family footprint — it drops into existing 5SJ4 panel layouts without rewiring or busbar repositioning.
Neutral conductor is not switched (1-pole only), so this breaker protects the phase leg only; the neutral bar in the panel must be continuous.