Siemens SIRIUS 3RH2 Contactor Relay, 10 A, 4NO, 690 V ac

Protect your motors and circuits against current overloads with this contactor relay from Siemens' SIRIUS Innovation range. It's a quality safeguard specifically designed for the protection of motor branch circuits and motor branch circuit components. You can install this unit with your contactors as part of a motor starter or in a control panel or centre. The four NO (normally open) auxiliary contacts disconnect the power supply in the event of electricity surges to prevent electrical shocks and fires that can cause costly damage to equipment and extended downtimes.

• Wide operating temperature range of -25°C to +60°C for use in extreme climates
• DIN rail mounting style enables fast and space-saving installation
• Expansion capability by up to four contacts through the use of snap-on auxiliary switch blocks
• IP20 (ingress protection) rating indicates it's touch-proof for added electrical safety

There are thermal and electronic overload relays. Thermal overload relays use a bi-metallic plate to detect current spikes. Electronic overload relays like this one use temperature sensors to measure the load current and often come with selected trip classes.