Step 6 - Condensate Drain; Horizontal Units; Vertical Units; Step 7 - Piping Connections - Carrier AQUAZONE 50HQL072-120 Installation, Start-Up And Service Instructions Manual

Step 6 — Condensate Drain
HORIZONTAL UNITS (50HQL) — Slope the unit toward
the drain at a 1 / in. per foot pitch. See Fig. 5. If it is not possi-
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ble to meet the required pitch, a condensate pump should be
installed at the unit to pump condensate to building drain.
Horizontal units are not internally trapped, therefore an ex-
ternal trap is necessary. Each unit must be installed with its
own individual trap and means to flush or blowout the conden-
sate drain line. Do not install units with a common trap or vent.
For typical condensate connections see Fig. 6.
NOTE: Never use a pipe size smaller than the connection.
VERTICAL UNITS (50VQL) — Each unit must be installed
with its own individual trap, vent and means to flush or blow-
out the condensate drain line. Do not install units with a com-
mon trap or vent. See Fig. 6.
Consider the following:
• Units are typically installed directly above each other on
successive floors with condensate drains located near the
units.
• Connect the unit condensate drain connection to the
building condensate drain with a 1-in. drain line.
• The horizontal run of a condensate hose is usually too
short to cause drainage problems, however pitch the hori-
zontal run of the condensate line should be at least
1 inch for every 10 feet of run in the direction of flow.
Avoid low points and unpitched piping since dirt collects
in low or level areas and may cause stoppage and
overflow.
• Install a condensate trap at each unit with the top of
the trap positioned below the unit condensate drain
connection.
• Design the length of the trap (water-seal) based upon the
amount of positive or negative pressure on the drain pan.
As a rule, 1-in. of trap is required for each inch of nega-
tive pressure on the unit.
VENTING — A vent should be installed in the condensate
line of any application which may allow dirt or air to collect in
the line. Consider the following:
• Always install a vent where an application requires a
long horizontal run.
• Always install a vent where large units are working
against higher external static pressure and to allow
proper drainage for multiple units connected to the same
condensate main.
• Be sure to support the line where anticipated sagging
from the condensate or when "double trapping" may
occur.
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Fig. 5 — Horizontal Unit Pitch
1/4" Pitch for
Drainage
Pitch Toward
Drain
Drain Connection
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• If condensate pump is present on unit, be sure drain con-
nections have a check valve to prevent back flow of con-
densate into other units.
Step 7 — Piping Connections —
application, there are 3 types of WSHP piping systems to choose
from: water loop, ground-water and ground loop. Refer to the
Carrier System Design Manual for additional information.
All WSHP units utilize low temperature soldered female
pipe thread fittings for water connections to prevent annealing
and out-of-round leak problems which are typically associated
with high temperature brazed connections. Refer to Tables 1
and 2 for connection sizes. When making piping connections,
consider the following:
• A backup wrench must be used when making screw con-
nections to unit to prevent internal damage to piping.
• Insulation may be required on piping to avoid condensa-
tion in the case where fluid in loop piping operates at
temperatures below dew point of adjacent air.
• Piping systems that contain steel pipes or fittings may
be subject to galvanic corrosion. Dielectric fittings may
be used to isolate the steel parts of the system to avoid
galvanic corrosion.
WATER LOOP APPLICATIONS — Water loop applications
usually include a number of units plumbed to a common pip-
ing system. Maintenance to any of these units can introduce air
into the piping system. Therefore, air elimination equipment
comprises a major portion of the mechanical room plumbing.
The flow rate is usually set between 2.25 and 3 gpm per ton
of cooling capacity. For proper maintenance and servicing,
pressure-temperature (P/T) ports are necessary for temperature
and flow verification.
In addition to complying with any applicable codes, consid-
er the following for system piping:
• Piping systems utilizing water temperatures below
50 F require 1 / -in. closed cell insulation on all piping
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surfaces to eliminate condensation.
• All plastic to metal threaded fittings should be avoided
due to the potential to leak. Use a flange fitted substitute.
• Teflon tape thread sealant is recommended to minimize
internal fouling of the heat exchanger.
• Use backup wrench. Do not overtighten connections.
• Route piping to avoid service access areas to unit.
• The piping system should be flushed prior to operation to
remove dirt and foreign materials from the system.
GROUND-LOOP APPLICATIONS — Temperatures be-
tween 25 and 110 F and a cooling capacity of 2.25 to
3 gpm of flow per ton are recommended. In addition to
complying with any applicable codes, consider the follow-
ing for system piping:
• Piping materials should be limited to only polyethylene
fusion in the buried sections of the loop.
NOTE: Trap should be deep enough to offset maximum unit static
difference.
Fig. 6 — Trap Condensate Drain
Depending on the