JOHNSON CONTROLS
28
FORM 100.50-NOM12
ISSUE DATE: 04/02/2019
SECTION 2 – INSTALLATION
FILTERS
Two-inch “throwaway” filters are standard and factory
installed in a filter rack located prior to the evapora-
tor coil. Any optional pre-filters ordered with the unit
is shipped inside the unit, but must be filed installed.
The unit can also be ordered with an extended cabinet
and 95% efficient post-filters. These post-filters are in-
stalled at the factory.
Pre-filters must always be installed ahead of the evapo-
rator coil. Post and pre-filters must be kept clean and
replaced with the same size and type as shipped with
the unit. Dirty filters will reduce the capacity of the unit
and may result in frosted coils and safety shutdowns.
Required filter sizes and qualities are shown in
. The unit should never be operated for
any length of time without the proper filters installed
in the unit.
CONDENSATE DRAIN
Condensate Drain Piping
The two cooling coils are located in the units so that
the supply air is drawn through them. This results in
the condensate being subjected to negative (-) static
pressure. Unless some means of pressure equalization
is provided in the condensate drain, the air rushing
back through the drainpipe will cause the condensate
to build up in the drain pan. As the unit continues to
operate, the accumulated water is carried with the air
stream, overfilling the drain pan causing possible water
leaks into the supply duct and/or causing water damage
in the building. A trap must be installed to prevent this
condensate water build-up (
Condensate Drain Trap
For “Draw-through” applications install a trapped con-
densate drain line at unit drain connection (
see Figure
) according to all governing codes. “H”
dimension must be at least 1 inch greater than design
Total Static Pressure (TSP) of fan.
The trap and drain lines should be protected from
freezing. Plumbing must conform to local codes. Use
a sealing compound on male pipe threads. Install con-
densate drain lines from the 1-1/4 inch NPT female
connections on the unit to an open drain.
The unit must be properly trapped and
charged with water before the units are
started.
DRAIN
PAN
DRAIN
PAN
DRAIN
PAN
DRAIN
NIPPLE
TRAP
NO.1 - FAN OFF
NO. 2 - TRAP CONDITION WHEN FAN STARTS
NO. 3 - FAN RUNNING AND CONDENSATE
COOLING COIL
DRAIN PAN
LD06342-1
FIGURE 5 -
DRAIN TRAP SHOWING WATER
LOCATION DURING DRAW THROUGH OPERATION
STAGES
H Must Be At Least
1 Plus Fan Total
Static Pressure
H
"X"= 1/2 "H"
X
LD05370
FIGURE 6 -
TRAP DETAIL FOR DRAW THROUGH
APPLICATION
AIR HOODS FOR ECONOMIZER
There are three economizer outside air intake hoods
provided with the unit. The hood on the end of the unit
is factory mounted. The two front and rear hoods are
made operational per the following instructions:
1. Remove the screws holding the economizer hood
shipping covers in place. Discard covers.
2. Apply a bead of RTV sealer along the edge of
both hoods and each pivot joint to prevent water
leakage.
3. Rotate the hoods out (each hood is hinged). Secure
the hoods with screws along the top and sides.
4. Seal any unused screw holes with RTV or by re-
placing the screw.