Johnson Controls ZL Series Installation Manual page 10

5. For gas heating models equipped with Smart
Equipment™ control, you must move the
supply air temperature (SAT) sensor to the
working position to ensure correct SAT
readings. The SAT sensor is shipped in the
supply air compartment.
a. Move the SAT sensor to the inside of the
supply air duct. See Item A in Figure 5.
b. Use the excess wire available to its full
length to drop or mount the SAT sensor
in the duct. Avoid close contact with the
gas heat exchanger.
c. Use the shipping bracket to hold the
SAT sensor in the supply air stream.
See Figure 3 for the factory SAT sensor
location and Figure 5 for the sensor
relocation.
Figure 3: Supply air temperature sensor
6. For units equipped with an economizer or
motorized OD air damper, you must move
the return air temperature (RAT) sensor to
the working position to ensure correct RAT
readings. See Item B in Figure 5.
a. Move the RAT sensor to the inside
of the return air duct, verifying that
the sensor is at least 6 in. below the
unit duct opening. The sensor must
read the return air temperature, not
mixed return air and outdoor air
temperatures.
b. Use the excess wire available to its full
length to drop or mount the RAT sensor
in the duct.
c. You can use the shipping bracket to
hold the RAT sensor in the return air
stream. See Figure 4 for the factory RAT
sensor location and Figure 5 for the
sensor relocation.
10 Installation Manual ZL Series 7.5- 12.5 Ton 60 Hertz R-410A
Figure 4: Return air temperature sensor
Figure 5: Supply and return air ducts
7. If an optional return air smoke detector is
installed, you must move the return air sensor
from the factory shipped position (upside
down) to the working position (right side up).
See Figure 6 then slide the flex tube over the
stub and tighten, see Figure 7.
Johnson Controls Ducted Systems
A Filter rack and filters
B RAT sensor
A Supply air duct
B Return air duct