Let's talk about the basics of electric actuators.
Normally closed type actuator working principle.
When the room temperature reaches the temperature set by the temperature controller, the positive thermistor (PTC) inside the electric actuator starts to work, heating the top rod to raise the valve open, and vice versa, the room temperature decreases, the thermostat is disconnected, the actuator cools down, the top rod shrinks, and the valve closes.
Normally open type actuator working principle.
When the indoor temperature reaches the temperature set by the temperature controller, the positive thermistor (PTC) inside the electric actuator starts to work, heating the top rod down to close the valve, and vice versa, the indoor temperature decreases, the thermostat is disconnected, the actuator cools down, the top rod rises, and the valve opens.
How to choose normally open and normally closed actuators?
1、In the centralized heating area, normally open electric actuator is used.
Reason: Generally in the northern areas, the climate is colder. Residents use electric heat actuator and thermostat mainly for the purpose of saving heating cost in the district of heat metering charge. Hot water enters the home and is ready to be turned on. Normally open actuators ensure the safety of use, even if there is a power outage, or if the main power is accidentally turned off when you go out, the heating still flows smoothly and does not lead to frozen pipes and property damage.
2、In the southern single-family heating area, also including centralized heating, with wall-hung boilers or heat pumps as the heat source of the building. Normally closed electric heat actuator is used.
Reason: The heating area of the separate heat source is generally in the south, where the climate is warmer. Residents use electric heat actuators and thermostats mainly for the purpose of time-sharing heating and saving gas or electricity. Normally closed actuators ensure energy efficiency in use, while preventing the heat source from automatically igniting and wasting energy.
Of course, you can also use a central controller, which can better take the thermostat commands of each room, unified analysis and summarization, and linkage processing of the host of cooling and heating sources, to better achieve energy saving and comfort.
After choosing a good actuator, you still need to match an excellent thermostat to achieve true system optimization. Using a thermostat that can be controlled with a cell phone is bound to become the mainstream of the industry. Its network interface, for the later smart home gateway, has reserved a mature interface, which can directly access the smart home platform.
Normally open electric heating actuator, wiring is connected to the valve off terminal of the thermostat, normally closed electric heating actuator, wiring is connected to the valve on terminal of the thermostat, this point must be noted, otherwise it will certainly cause the reverse operation of the entire system. Resulting in heating or cooling water flow, in the time when it should be open to close, the time to close. Unnecessary after-sales service occurs.