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Johnson Controls Unitary Products
Smoke Detectors
The factory-installed smoke detector will shut down operation of
the unit by interrupting power to the UCB when smoke is
detected within its mounting compartment. The smoke detector
option is available for both supply and/or return air configura-
tions. Be aware that the supply air configuration has the sensor
component mounted in the blower section, with its control mod-
ule mounted in the return air compartment.
The detector must be tested and maintained on a regular basis
according to NFPA 72 requirements and cleaned at least once
a year. For specific troubleshooting and maintenance
procedures, please refer to the smoke detector's installation
instructions which accompanies the unit.
Motorized Outdoor Damper
The Motorized Outdoor Damper can be a factory installed
option or a field installed accessory. If factory installed, refer to
the instructions included with the outdoor air hood to complete
the assembly. Field installed Motorized Outdoor Damper
accessories include complete instructions for installation.
Economizer
The Economizer can be a factory installed option or a field
installed accessory. If factory installed, refer to the instructions
included with the outdoor air hood to complete the assembly.
Field installed Economizer accessories include complete
instructions for installation.
There are two Economizer options:
1.
Down Flow, End Return Horizontal applications which
include Fresh Air Hood, Exhaust Hood with Barometric
Relief.
2.
Horizontal Flow application (Field Installed Kit Only) that
requires the purchase of a barometric relief hood.
3.
With the Down Flow, End Return Horizontal application it is
required to save the two Side Panels for the economizer
hood tops (See Figure 20).
Power Exhaust
The Power Exhaust can be a factory installed option or a field
installed accessory. If factory installed, refer to the instructions
included with the outdoor air hood to complete the assembly.
Field installed Power Exhaust accessories include complete
instructions for installation.
The Power Exhaust factory installed option is for Down Flow
application only.
There are two field installed Power Exhaust accessories:
1.
Down Flow application.
2.
Horizontal Flow application that requires the purchase of a
barometric relief hood.
Rain Hood
All of the hood components, including the filters, the gasketing
and the hardware for assembling, are packaged and located
between the condenser coil section and the main unit cabinet, if
the unit has factory installed options. If field installed
accessories are being installed all parts necessary for the
installation comes in the accessory.
Optional Variable Air Volume (VAV)
A variable air volume (VAV) option using a variable frequency
drive (VFD) is available for applications requiring a constant
supply-duct static pressure. A differential pressure transducer is
used to monitor supply duct static pressure and return a speed
reference signal to the VFD to control the output of the indoor
blower motor.
Duct Static Pressure Transducer
A 0-5" WC pressure transducer, located in the control box
compartment, is used to sense static (gauge) pressure in the
supply air duct and convert this pressure measurement to a
proportional 0-5 VDC electrical output. Pressure-transmitting
plastic tubing (1/4" diameter) must be field supplied and
installed from the transducer to both the ductwork and to the
atmosphere. Connect the tubing from the 'HIGH' pressure tap of
The use of duct smoke detectors have specific limitations
as established by the National Fire Protection
Association. Duct smoke detectors are; NOT a substitute
for an open area smoke detector, NOT a substitute for
early warning detection, and NOT a replacement for a
building's regular fire detection system. Refer to NFPA
Code 72 and Standard 90A for additional information.
Factory-installed smoke detectors may be subjected to
extreme temperatures during "off" times due to outside air
infiltration. These smoke detectors have an operational
limit of -4°F to 158°F. Smoke detectors installed in areas
that could be outside this range will have to be relocated to
prevent false alarms.
To assure adequate airflow reaches the smoke detector's
sensor, make sure that the holes of the sampling tube
face into the air stream, and that the far-end of the
sampling tube is sealed with the plastic end cap.
In addition, the unit's supply airflow must be adjusted to
provide a pressure differential across the smoke
detector's sampling and exhaust ports of at least 0.01
inches of water and no more than 1.11 inches of water, as
measured by a manometer.
