Cleveland Controls AFS-262-320 is a normally open air pressure sensing switch 120V 0.05" to 2" W.C.

Model AFS-262 is a general-purpose proving switch designed for HVAC and Energy Management applications. It can be used to sense positive, negative, or differential air pressure. The plated housing contains a diaphragm, a calibration spring and a snap-acting SPDT switch. The AFS-262 has a field adjustable set point range of 0.05″ wc to 2.0″ wc. The screw terminals are protected by an enclosure that accepts 1/2″ conduit. This switch has an SPDT contact arrangement. It is equipped with two compression ferrule and nut sample line connectors that accept 1/4” OD rigid tubing.

The plated housing contains a diaphragm, a calibration spring and a snap-acting SPDT switch.The sample connections located on each side of the diaphragm accept ¼" OD metallic tubing via the integral compression ferrule and nut. An enclosure cover guards against accidental contact with the live switch terminal screws and the set point adjusting screw. The enclosure cover will accept a 1/2" conduit connection.

Mounting

Select a mounting location which is free from vibration. The AFS-262 must be mounted with the diaphragm in any vertical plane in order to obtain the lowest specified operating set point. Avoid mounting with the sample line connections in the "up" position. Surface mount via the two 3 ⁄16" diameter holes in the integral mounting bracket. The mounting holes are 3-7/8" apart.

Air Sampling Connection

The AFS-262 is designed to accept firmwall sample lines of 1/4" OD tubing by means of ferrule and nut compression connections. For sample lines of up to 10 feet, 1/4" OD tubing is acceptable. For lines up to 20 feet, use 1/4" ID tubing. For lines up to 60 feet, use 1/2" ID tubing. A 1/4" OD adapter, suitable for slip-on flexible tubing is available: order part number 18311. Locate the sampling probe a minimum of 1.5 duct diameters downstream from the air source. Install the sampling probe as close to the center of the airstream as possible. Refer to Figure 2 to identify the high pressure inlet (H) and the low pressure inlet (L). Select one of the following five application options, and connect the sample lines as recommended.