50027910-001 DIFFERENTIAL PRESSURE SWITCH
69-2205—03
2
Fig. 2. Pressure switch dimensions.
Mounting position:
mount vertically (upright) with
logo right-side up.
Approvals
Underwriters Laboratories Inc. Approved: MP2168
Canadian Underwriter Laboratories Inc. Approved:
MP2168
INSTALLATION
• Read these instructions carefully. Failure to follow
them could damage the product or cause a
hazardous condition. This control must be installed
in accordance with the local code and regulations.
• Check ratings and descriptions given in the
Specifications section to ensure the product is
suitable for your application.
• Installer must be a trained, experienced service
technician.
IMPORTANT
Do not install the switch in an area where tem-
perature exceeds rating of -40F to 190F (-40C
to 88C)
1.
Disconnect power from the Humidifier before
installing.
2.
Mount the switch vertically with pressure con-
nectors facing down, using provided self-tap-
ping screws to secure the switch to the duct.
IMPORTANT
Calibration accuracy requires that the switch
be mounted vertically (as pictured in Fig. 3).
Fig. 3. Pressure switch—oriented vertically.
3.
The return duct is recommended, however the
switch can also be mounted to the supply duct.
Fig. 4. Mounting the pressure switch.
4.
Cut a 3/4-in. diameter hole in the duct within 10
feet of the switch to ensure the provided tubing
reaches the pressure tap elbow.
5.
Insert the grommet into the duct hole, then
insert the tube elbow into the grommet.
6.
Connect the tubing to the elbow fitting and the
other end to the applicable pressure connection
on the switch:
a. Black connection if installed on the supply
b. Grey connection if installed on the return
IMPORTANT
With low-speed airflow or variable speed sys-
tems it is recommended to run tubing to both
the supply and return ducts.
M27301
4-13/64 (107)
3-13/16 (97)
3-15/16
(100)
[2] 1/2 (13)
[2] 1/4 (6)
3/16
(5)
5/64
(2)
Ø3-1/4
(83)
FULL
R
Ø3/16
(5)
27/32
(21)
2-1/64 (51)
1-19/32 (41)
POSITIVE
PRESSURE
PORT
NEGATIVE
PRESSURE
PORT
COMMON (C) TERMINAL
1/4 (6) X 1/32 (1) THICK
QUICK CONNECT
NORMALLY OPEN (NO)
TERMINAL 1/4 (6) X 1/32 (1)
THICK QUICK CONNECT
C
1
2
3
1
2 3
2
3
NC
NO
+
PI
ASSEMBLED
IN MEXICO
M27300
M27303
A
B
SUPPLY DUCT INSTALL
- AIR LINE ONLY TO TAP A,
CONNECTED TO THE + PORT ON THE AIR FLOW SWITCH
RETURN DUCT INSTALL
- AIR LINE ONLY TO TAP B,
CONNECTED TO THE – PORT ON THE AIR FLOW SWITCH
SUPPLY/RETURN DUCT INSTALL
- AIR LINE CONNECTED
TO BOTH THE + AND – PORTS ON THE AIR FLOW SWITCH
