Air Flow Switch Operation

Airflow actuated hvac switches use this switch to sense changes in airflow velocity.

Air flow switch operation.

Flow switches are used in spas and hot tubs to tell the system to turn on and off. The principle of operation is quite simple. Air flow exerts a force on a paddle actuating a dust tight spdt micro switch. To handle air velocities greater than 920 fpm the paddle may be cut at a precalibrated mark.

The flow switch is factory set to switch at 195 fpm. Sometimes pressure switches are employed to designate deficient pressure to ensure that the required flow is maintained. A damaged or defective flow switch will keep the spa from receiving electricity. The trip signal will indicate to the pump to turn on or turn off.

In the presence of fluid flow controlled movement of the piston actuates an external hermetically sealed reed switch. Rely on grainger for a wide range of duct pressure switch options. Aflow switchoperates by conveying a trip motion relay reed switch paddle to another machine within the system usually a pump. It is necessary to provide damage protection and circuit cooling or adjust flow rates that are too high or too low.

An air switch senses positive negative or differential air pressure and actuates an internal switch. Flow switch operating principle is based on a free floating magnetic piston which responds only to the motion of fluids within the line not to static or system pressures. When the pressures from two different sources in a process are connected across the sensing diaphragm metallic or elastomeric as the case may be the pressure difference creates a force which then overcomes that of a pre tensioned spring and in the process moves a balancing arm or mechanism to effect the minimal movement required to actuate the micro switch es of the switch. Flow switches are mechanical devices used in controlling the flow of air steam or liquid.

Most air purge systems consist of a fan with a motor some type of filter housing and a filter cartridge all stored in a weatherproof environment. The switching point may be adjusted continuously within a wide range making the lps useful in a wide variety of applications. This switch can be used to actuate audible or visual alarms as well as relays or other controls. Often used to detect clogged air filters and iced air conditioner coils these switches sense small changes in pressure between two points in your duct.

If you receive an error code when you try to turn the hot tub or spa on troubleshooting the flow switch can help indicate where a problem exists.