Daikin RDT, Руководство по установке и обслуживанию, Страница: 35 / 152

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www.DaikinApplied.com 35 IM 893-10 • ROOFPAK SINGLEZONE UNITS
Unit Piping
Condensate Drain Connection
WARNING
Drain pans must be cleaned periodically. Material in uncleaned
drain pans can cause disease.
Cleaning should be performed by qualified personnel.
The unit is provided with a 1.5ʺ male NPT condensate drain
connection. Refer to certified drawings for the exact location.
For proper drainage, level the unit and drain pan side to side
and install a P-trap
RPS units may have positive or negative pressure sections.
Use traps in both cases with extra care given to negative
pressure sections. In Figure 35, dimension “A” should be
a minimum of 8ʺ (203 mm). As a conservative measure to
prevent the cabinet static pressure from blowing or drawing
the water out of the trap and causing air leakage, dimension A
should be two times the maximum static pressure encountered
in the coil section in inches w.c.
Draining condensate directly onto the roof may be acceptable;
refer to local codes. Provide a small drip pad of stone, mortar,
wood, or metal to protect the roof against possible damage.
If condensate is piped into the building drainage system, pitch
the drain line away from the unit a minimum of 1/8ʺ per foot.
The drain line must penetrate the roof external to the unit.
Refer to local codes for additional requirements. Sealed drain
lines require venting to provide proper condensate flow.
Where the cooling coils have intermediate condensate pans on
the face of the evaporator coil, copper tubes near both ends of
the coil provide drainage to the main drain pan. Check that the
copper tubes are in place and open before the unit is put into
operation.
On units with staggered cooling coils, the upper drain pan
drains into the lower coil drain pan through a copper tube
near the center of the drain pan. Check that this tube is open
before putting the unit into operation and as a part of routine
maintenance.
Drain pans in any air conditioning unit have some moisture in
them, allowing micro-organisms to grow. Therefor, periodically
clean the drain pan to prevent this buildup from plugging the
drain and causing the drain pan to overflow.
Figure 36: Condensate Drain Connection
Gas Piping
See the “Installation” section of the gas-fired furnace
installation manual, IM 684 or IM 685 .
Hot Water Coil Piping
CAUTION
Coil freeze possible. Can damage equipment. Follow
instructions for mixing antifreeze solution used. Some
products have higher freezing points in their natural state
than when mixed with water. The freezing of coils is not the
responsibility of Daikin. Refer to Winterizing Water Coils on
page 138 .
Hot water coils are provided without valves for field piping or
piped with three-way valves and actuator motors.
NOTE: All coils have vents and drains factory installed.
Hot water coils are not normally recommended for use with
entering air temperatures below 40°F (4°C). No control system
can guarantee a 100% safeguard against coil freeze-up. Glycol
solutions or brines are the only freeze-safe media for operation
of water coils at low entering air temperature conditions.
When no factory piping or valve is included, the coil
connections are 1-5/8ʺ ODM copper.
NOTE: With the factory piping and valve package, field piping
connections are the same NPT size as the valve with
female threading (see Figure 38 ).
Refer to the certified drawings for the recommended piping
entrance locations. Seal all piping penetrations to prevent air
and water leakage.
NOTE: Factory-installed water valves and piping are bronze,
brass, and copper. Dissimilar metals within the
plumbing system can cause galvanic corrosion. To
avoid corrosion, provide proper dielectric fittings as
well as appropriate water treatment.