035-18525-001-B-0203
Unitary Products Group
9
DRAIN CONNECTION
The drain line MUST be trapped because the coil is
located on the negative side of the supply air blower. It
must also be protected from freezing temperatures.
A 7/8" OD stub connection is provided within the cabi-
net on both ends of the condensate drain pan for either
left hand or right hand piping connections. Refer to
Figure 6 for recommended drain piping.
The drain line is usually located on the same end of the
coil section as the refrigerant connections. The line
should be insulated where moisture drippage will be
objectionable or cause damage to the area. Seal the
unused drain connection with suitable mastic.
The 5" dimension must equal or exceed the negative
static pressure developed by the supply air blower. If it
does not, the condensate will not drain properly and
may overflow the drain pan. The trap must be at least
2" deep to maintain a water seal under all operating
conditions, especially during blower start up.
REFRIGERANT MAINS
Many service problems can be avoided by taking ade-
quate precautions to provide an internally clean and
dry system and by using procedures and materials that
conform with established standards.
Hard drawn copper tubing should be used where no
appreciable amount to bending around pipes or other
obstructions is necessary. Use long radius ells wher-
ever possible. If soft copper is used, care should be
taken to avoid sharp bends, which may cause a restric-
tion.
Fiber glass insulation and a sealing material such as
permagum should be packed around refrigerant lines
where they penetrate a wall to reduce vibration and to
retain some flexibility.
Support all refrigerant lines at minimum intervals with
suitable hangers, brackets or clamps.
Braze all copper to copper joints with Sil-Fos 5 or
equivalent brazing material. DO NOT use soft solder.
Never braze or solder the liquid and suction lines
together.
The complete suction line should be insulated with no
less than 1/2" ARMAFLEX or equivalent.
If it is desirable to tape or wire the liquid and suction
lines together for support purposes, they must be com-
pletely insulated from each other.
INSTALLING REFRIGERANT MAINS
The units are evacuated and dehydrated at the factory
and shipped with a holding charge of Refrigerant-22.
The suction and liquid connections are sealed with
copper discs.
Before starting installation of the mains, be sure the
unit has not developed a leak in transit by drilling a
small hole in the sealing discs. If pressure still exists,
the circuit may be considered leak free. If pressure
does not exist, the coil should be leak tested and the
necessary repairs should be made.
NOTE: To minimize the possibility of system failure due
to dirt and moisture, a filter-drier must be
installed in each liquid line as close to the
evaporator as possible. Filter-dryers are not
supplied with the evaporator blowers. They
are supplied with the matching YORK con-
densing sections.
FIGURE 5: RETURN AIR GRILLE ACCESSORY
(VERTICAL)
FIGURE 6: RECOMMENDED DRAIN PIPING
5 "
2 "
P L A S T I C
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S T E E L
S T U B
C O N N E C T I O N
H O S E C L A M P S
E V A P O R A T O R
C O I L
D R A I N P A N
* F A C T O R Y S U P P L I E D
