10
English
•
Use of oxygen could result in an explosion resulting in seri-
ous injury or death. Only use dry nitrogen gas.
•
Refrigerant gas may produce toxic gas if it comes in contact
with fire (as from a heater, stove or cooking device
)
.
Exposure to this gas could cause severe injury or death.
•
Do not use flux when brazing refrigerant piping. Therefore,
use the phosphor copper brazing filler metal (BCuP) which
does not require flux.
Flux has an extremely negative effect on refrigerant piping
systems. For instance, if chlorine based flux is used, it will
cause piping corrosion. Flux containing fluorine will damage
refrigerant oil.
6.
DRAIN PIPING WORK
The coil drain pan has a primary and a secondary drain with 3/4"
NPT female connections. The connectors required are 3/4" NPT
male, either PVC or metal pipe, and should be hand tightened to
a torque of no more than 37 in-lbs. to prevent damage to the
drain pan connection. An insertion depth of approximately 3/8"
to 1/2" (3-5 turns) should be expected at this torque.
1.
Ensure drain pan hole is not obstructed.
2.
To prevent potential sweating and dripping on to finished
space, it may be necessary to insulate the condensate drain
line located inside the building. Use Armaflex® or similar
material.
A secondary condensate drain connection has been provided
for areas where the building codes require it. Use a downward
slope of at least 1/100 to provide free drainage, or as required
by local code. Provide required support to the drain line to
prevent bowing. If the secondary drain line is required, run the
line separately from the primary drain and end it where conden-
sate discharge can be easily seen.
Drain port labeled (A) in Figure 10 is the primary drain and con-
densate drain line must be attached to this drain port.
Drain port (B) is for the secondary drain line (if used). In applica-
tions where the cased coil is installed in areas where the return
air humidity levels may be above 65% relative humidity, coupled
with total external static pressure levels above 0.5” e.s.p., in-
stallation of a field fabricated or field supplied secondary drain
pan is recommended to be placed under the coil cabinet
enclosure.
B
A
Figure 10
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Water coming from secondary line means the coil primary
drain is plugged and needs immediate attention.
•
Insulate drain lines located inside the building or above a
finished living space to prevent sweating. Install a conden-
sate trap to ensure proper drainage.
•
Some installations may require a field fabricated or field sup-
plied secondary drain pan under the coil cabinet enclosure.
The installation must include a “P” style trap that is located
as close as is practical to the evaporator coil. See Figure 11
for details of a typical condensate line “P” trap.
•
Trapped lines are required by many local codes. In the ab-
sence of any prevailing local codes, please refer to the re-
quirements listed in the uniform mechanical building code. A
drain trap in a draw-through application prevents air from
being drawn back through the drain line during fan opera-
tion
,
thus preventing condensate from draining and if con-
nected to a sewer line
,
to prevent sewer gases from being
drawn into the airstream during blower operation.
Drain
Connection
Cased Coil
POSITIVE LIQUID
SEAL REQUIRED
AT TRAP
Figure 11
