What is the maximum current online voltage for thermostats?

The maximum current online voltage for thermostats is 24 volts. This voltage level is commonly used in low-voltage control systems for thermostats that operate HVAC equipment. Most residential heating and cooling systems are designed to function safely and efficiently with a control voltage of 24 volts, which is supplied by a step-down transformer from the standard 120 or 240 volts found in electrical systems.

Utilizing 24 volts for thermostat operation provides a balance between sufficient power to control devices while minimizing the risk of electrical shock compared to higher voltages. This makes it a standard choice across many HVAC systems, promoting safety and compatibility.

While the other voltage options are used in different applications within electrical systems, they do not correspond to the standard voltage for thermostats in HVAC systems. Hence, 24 volts is the designated voltage that enables reliable function in controlling heating and cooling equipment.