JOHNSON CONTROLS
37
SECTION 2 – INSTALLATION
FORM 100.50-NOM12
ISSUE DATE: 04/02/2019
2
TRANSDUCER PNEUMATIC TUBING
Static Pressure Control Plastic Tubing
(Pneumatic Tubing)
Duct static transducers (all VAV units) and any unit with
an optional building pressure control transducer, require
pneumatic tubing to be field supplied and installed. The
High side of the respective transducer must be routed to
the location in the building or ductwork where a con-
stant pressure is desired. Both the duct static transducer
(VAV only) and optional building pressure transducer
are mounted behind the left hand damper door. All wir-
ing from the transducers is factory installed.
Duct Static Transducer
Plastic tubing (1/4 inch ID) must be run from the high
pressure tap of the transducer to a static pressure tap
(field supplied) in the supply duct, located at a point
where constant pressure is desired. This is normally
2/3rds of the way down the duct, before the first take off.
Building Pressure Transducer
Plastic tubing (1/4 inch ID) must be run from the high
pressure tap of the building static pressure transducer
to a static pressure tap (field supplied) located in the
conditioned space. The tap should be placed in a lo-
cation where over pressurization will cause a problem
(e.g., in the lobby area where excessive pressure will
cause the doors to remain open). The tap should never
be placed above the ceiling.
This will allow for standard building pressure control
through the IPU board. There is an option to control
the VFD Driven Exhaust Fan speed through the BAS,
if desired. If the unit has a return fan, the same point
can be used to control the Modulating Exhaust Damp-
er. The point for BAS control can be enabled in the
Service key.
Static Pressure Probe Installation
On units with duct static transducers (VAV units) and
any unit with an optional building pressure, a factory
supplied Static Pressure Probe must be field installed
at the top of the rear corner post on the unit (see Figure
12 on page 38).
The factory supplied atmospheric pressure probe and
associated mounting hardware are shipped inside the
control panel. The hardware consists of a mounting
bracket and a short section of pneumatic tubing. The
pneumatic tubing must be field installed from a
factory pressure tap (next to the mounting location
for the static pressure probe) to the atmospheric
pressure probe (see Static Pressure Probe Installa-
tion Instructions (Form 100.50-N1)).
If the unit is equipped with both a building pressure
transducer and a duct static transducer, a “tee” is fac-
tory installed, and both the duct static pressure trans-
ducer and building pressure is connected to the “tee” -
both building static pressure transducer and duct static
transducer will use the same factory supplied atmo-
spheric pressure probe.
The “Low” side connection of the duct
static or building pressure transducers are
shipped with the pneumatic tubing factory
installed and routed, to the external fac-
tory pressure tap.
ROOF CURB INSTALLATION
General Information
When ordered, the roof curb is shipped knocked-down
in a separate container and needs to be field assem-
bled and installed. Refer to Installation Manual that
is shipped with the roof curb for specific instructions.
On full perimeter roof curb the opening in the roof
should not extend under the condenser section of the
curb. The condenser section of the roof curb is not in-
sulated and could result in condensation build up un-
der the condenser section as well as higher than normal
sound levels in the conditioned space.
The roof curb drawings contained in the Johnson Con-
trols literature are not intended as construction docu-
ments for the field fabrication of a roof curb. Johnson
Controls will not be responsible for the unit fit up,
leak integrity, or sound level with field fabricated roof
curbs. Construction documents for field fabricated
roof curbs are available upon request.
Wood or ber cant strips, roong felts,
roong material, caulking and curb-to-
roof fasteners are to be eld supplied.
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