The Siemens 3RH2921-2XN22-0GS0 is a front-mounted auxiliary switch block from the SIRIUS family, designed for use with contactor relays and power contactors. It provides 2 normally open and 2 normally closed contacts, with two of the NC contacts specifically rated as solid-state compatible — meaning they reliably switch low-level signals down to 17 V, 1 mA with a contact reliability of 1 faulty switching per 100 million operations. This variant is a customer-specific version, identified by the -0GS0 suffix and the petrol-colored label, and is intended for use with the 3RT2026-1FB40-1KS0 contactor. The spring-loaded terminals accept 2x (0.5... 1.5 mm²) with ferrule or 2x (0.5... 2.5 mm²) solid, and the block snaps onto a DIN rail.
The maximum thermal current is 10 A, but the switching capacity varies significantly with voltage and duty. For AC-15 control circuit use at 690 V, the rated operational current is 1 A — that's the figure to check for pilot duty on higher-voltage contactor coils. At 24 V DC the rated value is 10 A, dropping to 0.26 A at 600 V DC, so verify your load voltage against the DC switching curve. The insulation rating is 690 V AC with degree of pollution 3, and surge voltage resistance is 6 kV. This means the block is suitable for 400 V line-to-line panels and will handle typical transient overvoltages in industrial environments without flashover. The front protection class is IP20 — finger-safe but not washdown-rated, so keep it inside the enclosure.
Because it is a customer-specific variant (-0GS0 suffix), availability may be less immediate than a standard catalog number. The RFQ is the cleanest path to confirm lead time and pricing for this exact order code, especially if you are matching a petrol-labeled panel that was originally built to this variant.
The block measures 36 mm wide, 47.7 mm deep, and 41.5 mm high. The spring-loaded terminals are tool-less for solid wire up to 2.5 mm²; for ferruled stranded, the range is 0.5 to 1.5 mm². AWG equivalents are 2x (20... 14). The leading contact is 0, lagging switching is 0, and instantaneous contacts are 2 — meaning all four contacts switch simultaneously with no intentional delay.