Undervoltage release for ABB E1/T8 breakers
The ABB 1SDA038315R1 is an undervoltage release accessory designed for ABB and T8 series molded case circuit breakers. It trips the breaker when the supply voltage drops below its operating threshold, providing protection against brownout conditions or loss of control power. Supply voltage is 415-440V AC per IEC standards and 440-480V AC per UL standards — dual-rated for global panel builds. This is the voltage the release coil requires to keep the breaker closed; if the voltage falls outside this range, the release actuates and opens the breaker.
This release mounts inside the breaker mechanism of ABB and T8 frame MCCBs. It is a factory-fit accessory or field-installable option, not a standalone device — the breaker frame must accept the undervoltage release module.