This part is a kind of semiconductor called ACST67S.

Function of this product has OVER VOLTAGE PROTECTED AC POWER SWITCH.

Manufacturers : STMicroelectronics

Image and pinout :

Some of the text within the PDF file :

® ACST6-7S OVER VOLTAGE PROTECTED AC POWER SWITCH ASD™ AC Switch Family MAIN APPLICATIONS AC static switching in appliance & industrial control systems Induction motor drive actuator for: - Refrigerator / Freezer compressor - Dishwasher spray pump - Clothes drier tumble Actuator for the thermostat of a refrigerator or freezer s s s OUT G OUT COM G OUT COM FEATURES VDRM / VRRM = +/- 700V Avalanche controlled device IT(RMS)=1.5 A with no heat sink and Tamb = 40°C IT(RMS) = 6A with TCASE = 105 °C High noise immunity: static dV/dt > 200 V/µs Gate triggering current : IGT < 10 mA Snubberless turn off commutation: (dI/dt)c > 3.5A/ms D2PAK, I2PAK, TO-220FPAB or TO-220 package s s s s s s s s TO-220AB ACST6-7ST TO-220FPAB ACST6-7SFP OUT OUT G COM G OUT COM BENEFITS Enables equipm [ ... ]

ACST67S PDF Datasheet Download