Another requirement for new HVAC systems complying with the UL60335-2-40 is the audible and visual indication that a refrigerant leak has been detected. Typically, these can be located on or near the indoor air handler where the hazard can be most likely to be a potential fire risk.

According to the standard, refrigerant leak alarms (in accordance with GG.13.2.2) for general occupancy shall warn both audibly and visibly, such as both a loud 15dBA above background level buzzer and a flashing light installed where:

• Sleeping facilities
• People restricted in the movement
• Uncontrolled number of people are present
• Any space someone has access to without personally being acquainted with necessary safety precautions

TI collateral for designers: Status Indication Reference Design with LED and Audio Feedback.

Design Overview: The TIDA-03026 reference design functionality emulates status indication subsystems in various end equipments and can be used for these A2L detection systems. Audio feedback is also integrated to show a combined status indication design with LEDs and audio.

Features:

• Synchronize multiple LED drivers using variable PWM to create unique pulsing, blinking, and breathing effects with TLC59116
• TLC59116 I2C control makes adding additional LEDs simple by enabling user-experience customization across multiple platforms
• Easy-to-use TPA6211A1 audio amplifier simplifies audio design for faster time to market
• TPS22918 load switch drops LED driver standby current to 0.5µA, saving power for efficient system design