The wind pressure switch has two detection ports, namely a positive pressure detection port and a negative pressure detection port, and its cavity is divided into a positive pressure cavity and a negative pressure cavity. The two cavities are separated by a diaphragm. When there is a pressure source, the diaphragm moves to touch the microswitch to achieve the purpose of on/off.
There is a fine-tuning device ON the wind pressure switch, which changes the pressure of the spring to change the starting point and closing point (that is, the on point and the OFF point) of the wind pressure switch.
Usually, the sampling of wind pressure switch adopts negative pressure detection port, and the sampling device is installed in the negative pressure area of volute of forced exhaust fan. The sampling port of the sampling device is a pipe with an oblique angle, which forms a certain angle with the wind direction. The detected pressure value varies with the change of angle and wind speed. In order to meet the standard requirement of non-stop before 80Pa, many enterprises set the wind pressure value at 1 10Pa for stop.
Extended data:
Wind pressure switch is a kind of detection element, which is generally used in machinery that needs wind pressure, such as pneumatic press, pneumatic shearing machine, gas water heater, gas boiler, gas stove, wall-hung boiler and other electrical products that use gas. It uses the static pressure of gas to push the microswitch to realize the on-off of current.
The important function of the wind pressure switch is to ensure that the equipment can close the airway in time under the condition of poor exhaust, so as to ensure that the gas does not leak, thus protecting personal safety.
Basic parameters of wind pressure switch:
Generally, the parameters on the air pressure switch of water heater are: P=0.9m bar, pmax: = 10mbar, which is the air pressure unit, 1mbar= 100Pa, that is, the rated air pressure is 90Pa, which can be adjusted to 1000Pa at the maximum.
References:
Baidu encyclopedia-wind pressure switch