JOHNSON CONTROLS
84
FORM 145.05-NOM7
ISSUE DATE: 10/31/2019
SECTION 2 – INSTALLATION
RETURN, OUTDOOR, SUPPLY AIR, AND
MIXED AIR SENSORS
Return Air Sensor
All units require the installation of a return air sen-
sor. However, because of the variation of the return
air arrangements for this product the return air sensor
is shipped loose in the control enclosure and must be
field installed and wired to the Unit Controller. The
sensor is supplied with 25 foot leads terminated to plug
onto the Unit Controller. If a longer length is required,
inline butt splices can be used to increase the length. It
is important the return air sensor be located so it senses
the true return air temperature. The sensor is connected
at the J9 terminal strip, terminals 3 and 4.
Supply Air Sensor
All units come with a supply air sensors that are fac-
tory wired. The supply air sensor is wired to the Unit
Controller and mounted in the supply air section of the
unit.
Mixed Air Sensor
All units come with mixed air sensors that are factory
wired. The mixed air sensor is wired to the Unit Con-
troller and mounted in the inlet section of the unit.
Freezestat
Units equipped with a waterside economizer coil, hot
water coil, or steam coil come with a non-averaging
type freezestat installed on the inlet section of the unit.
See Freezestat Operation on page 135 for informa-
tion on the operation of the freezestat.
Outdoor Air Sensor
The outdoor air sensor is optional and can be ordered
with the unit. The sensor is standard when the air side
economizer option is ordered. The outdoor air sensor
is shipped loose in the control enclosure and must be
field installed and wired to the Unit Controller. The
sensor is supplied with 25 foot leads terminated to
plug onto the Unit Controller. If a longer length is
required, inline butt splices can be used to increase
the length. It is important the outdoor air sensor be
located so it senses the true outdoor air temperature.
The sensor is connected at the J9 terminal strip, ter-
minals 5 and 6.
STEAM HEAT
Specification
The steam coil is a factory installed option and is lo-
cated at the supply air outlet of the unit. The wiring for
the valve is connected to the Unit Controller and rout-
ed to the steam heating coil; however, the steam heat
control valve is not shipped with the unit. The valve
needs to be selected based on the type of heat, capac-
ity, and steam pressure. The valve should operate off
24VA C power supply with a 2–10VDC control signal.
The Unit Controller can be configured for direct acting
(2VDC closed, 10VDC open) or reverse acting (2VDC
open, 10VDC closed).
Steam Piping
Due to the variety of piping practices, it is advisable to
follow the recommendations of local authorities. They
can supply the installer with the proper building and
safety codes required for a safe and proper installation.
HOT WATER HEAT
Specification
The hot water coil is a factory installed option and is
located on the leaving side of the evaporator coil. The
piping connections are made through the top of the
unit. The unit can be ordered with a factory installed
two-way modulating valve package. The valve pack-
age includes the valve, actuator, wiring, and piping in-
ternal to the unit.
Piping must comply with local plumbing
codes and ordinances.
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