Siemens Auxiliary Switch Block, NO/NC Contacts, 80mm Height - Sirius Classic Series - 3RH1921-1DA11 Use this auxiliary switch block from Siemens to monitor the performance of your contactor. It's compatible with contactor relays and power contactors from the 3RH series, so fits easily into existing setups. The unit works by sending a signal to the control system if it detects any changes in the contactor. A broad operating temperature range between -25°C and +60°C means it can withstand harsh environments. You can use this component to signal indication and alarm systems in your control panel. • Surge voltage resistance of 6kV to withstand current overloads
• Screw-type terminals for secure electrical connection How durable is this auxiliary switch block? This component has a mechanical service life of 10 million switching cycles, so you can rely on it for long-term performance. For added durability, it has a contact reliability rating of one incorrect switching operation in 100 million operations, minimising the risk of failure in demanding conditions. How do I mount this auxiliary switch block? Thanks to the snap-on mounting, you can simply clip it onto the contactor for tool-free installation. Its compact dimensions of 10 (W) x 80 (H) x 71mm (D) will fit easily in a busy setup.