Johnson Controls F240AA Installation Guide

Figure 1: T ypical Application Inst allation fo r the

F240AA Pneumatic Airflow Switch

Normally
Open
Damper

Normally
Closed
Damper

Fan

Airflow
Switch

Control

Supply Air
20 psig

0.007 in.

(0.18 mm)

Pneumatic
Damper
Actuator

Return Air

Outside
Air

F240AA Pneumatic Airflow Switch

Installation Instructions

Part No. 24-7664-3124, Rev. A

Refer to the QuickLIT website for the most up-to-date version of this document.

Issued October 15, 2015

Applications

IMPORTANT: Use this F240AA Pneumatic Airflow

Switch only as an operating control. Where failure or
malfunction of the F240AA switch could lead to
personal injury or property damage to the controlled
equipment or other property , additional precautions
must be designed into the control system. Incorporate
and maintain other devices, such as supervisory or
alarm systems or safety or limit controls, intended to
warn of or protect against failure or malfunction of the
F240AA switch.

IMPORTANT: Utiliser ce F240AA Type Pneumatic
Airflow Switch uniquement en tant que dispositif de
régulation. Lorsqu'une défaillance ou un
dysfonctionnement du F240AA switch l risque de
provoquer des blessures ou d'endommager
l'équipement contrôlé ou un autre équipement, la
conception du système de contrôle doit intégrer des
dispositifs de protection supplémentaires. Veiller
dans ce cas à intégrer de façon permanente
d'autres dispositifs, tels que des systèmes de
supervision ou d'alarme, ou des dispositifs de
sécurité ou de limitation, ayant une fonction
d'avertissement ou de protection en cas de
défaillance ou de dysfonctionnement du
F240AA switch.

The F240AA Pneumatic Airflow Switch detects airflow
or the absence of airflow by responding only to the
velocity of air movement within a duct.

Typical applications include:

• make-up air systems

• air cooling or heating processes

• exhaust systems
The switch features a T ype 3R (NEMA)/IP43 en closure

with an integral mounting plate and a moun ting gasket.
It is calibrated for a maximum pneumatic input
pressure of 20 psig (138 kPa).

For a typical application installation for the
F240AA Pneumatic Airflow Switch, see Figure 1.

FIG:F240AA_smpl_app

Temperature

Restrictor

Absence of airflow during the normal operation of air
handling systems may cause overheating, coil icing, or
other conditions that may be detrimental to the
equipment.

F240AA Pneumatic Airflow Switch Installation Instructions

1

Installation

Figure 2: F240AA Airflow Switch with Type 3R (NEMA)/IP43 Enclosure Dimensions, in. [mm]

- -

1/4 [6] O.D. x

3/16 [4] I.D.

tubing

2

[51]

4

[102]

[116]

1-3/8

[35]

2-3/4

[70]

7-11/16

[197]

6-7/8
[175]

2-1/8 [54] Standard

3-1/8 [79] O pt ional

1/4 [6]

4

[102]

4

[102]

3-1/4

[83]

2

[51]

1-1/4

[32]

1-3/4

[45]

2-1/2

[64]

3-1/2

[89]

1-1/2

[38]

3

[76]

3

[76]

2-11/16

[68]

13/16

[21]

1/16

[2]

FIG:F240AA_dmnsns

3/16 [5] di am eter

mounting holes for

No. 10 screws, 4 places

[57]

Dimensions

4-9/16

Barbed connector for

2-1/4

Installation Procedure

Select the proper location and orientation. See

Mounting

1. Use the mounting plate gasket as a template and

2. Drill or punch screw holes.

.

mark hole positions.

3. Cut the center hole large enough for the paddle to
pass through.

4. Trim the paddle, if necessary (see Figure 3). The
standard paddle fits into ducts of 3 x 8 in.
(76 x 203 mm) minimum. Th e paddle ma y be
trimmed for installing in ducts as small as 3 x 6 in.
(76x152mm).

F240AA Pneumatic Airflow Switch Installation Instructions

2

Figure 3: Trimming the Paddle,

Dimensions, in. [mm]

3-15/16

[100]

3/16

[5]

FIG:F240AA_mnt_trm

Figure 4: Mounting the F240AA Switch in a

Horizontal Duct

FIG:hrzntl_mntg_ F240AA

Figure 5: Mounting the F240AA Switch in an

Angled Duct

shim

FIG:mntng_angl_dct_F240AA

Figure 6: Mounting the F240AA Switch in a

Vertical Duct

FIG:vrtc l_mntg_F2 40AA

Mounting

IMPORTANT: Mount the switch so that the housing

is level horizontally (or plumb vertically). Use a shim,
if necessary.

• When mounting the switch in a vertical duct where
the airflow is downward (Figure 6), you must
readj ust the minimum flow required to actuate the
switch (see Setup and Adjustments

on page 4).

no shim

• Install the switch so that the cover and interior are
accessible for adjustment.

• Ensure that the arrow on the side of the switch
body points in the direction of flow.

• Mount the F240AA switch on the top, side, or
bottom of a duct.

• Mount the switch in a horizontal duct whenever
possible. In a horizontal duct, the switch housing
must be level, and the paddle should be at
approximately a right angle to the airflow
(Figure 4).

• When mounting the switch in a horizontal duct that
is not horizontally true, check with a le vel and place
a shim under the switch mounting plate. Do not
mount the switch without a shim (Figure 5).

• When mounting the switch in a vertical duct where
the airflow is upward (Figure 6), see T able 2 for the
minimum flow required to actuate the switch. The
maximum air velocity should not exceed
2,000 FPM (10.16 m/s).

Note: When the switch is mounted in a vertical duct,
the values shown in Figure 10 do not apply.

!

F240AA Pneumatic Airflow Switch Installation Instructions

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