Daikin Trailblazer AGZ030E-070E, Инструкция по установке, эксплуатации и обслуживанию

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Remote Evaporators
www.DaikinApplied.com 21 IOM 1207-6 • TRAILBLAZER
®
MODEL AGZ CHILLERS
Evaporator installed above outdoor unit:
• 30 ft. maximum measured vertical distance, 75 ft
maximum vertical equivalent length is required to prevent
loss of liquid subcooling
Table 4: Remote Evaporator Piping Limitations
Piping Restriction 030-070 075-241
Maximum measured actual piping
distance between the unit and the
remote evaporator
90 ft. 150 ft.
Maximum total equivalent feet of
distance between the unit and
evaporator including friction losses of
elbows and traps
150 ft. 300 ft.
Notes: Horizontal sections of the suction lines must be
downward sloping toward the compressor with 1 inch slope
per 10 foot of piping run to assist oil return.
Field isolation of charge maximum piping lengths are located
in Table 9 on page 25.
Table 5: Fitting Losses Equivalent Feet of Pipe
Line Size
In .OD
Angle
Valve
Globe
Valve
90° Std .
Radius
Elbow
90° Long
Radius
Elbow
7/8 9.0 22.0 2.0 1.4
1 1/8 12.0 29.0 2.6 1.7
1 3/8 15.0 38.0 3.3 2.3
1 5/8 18.0 43.0 4.0 2.6
2 1/8 24.0 55.0 5.0 3.3
2 5/8 29.0 69.0 6.0 4.1
3 1/8 35.0 84.0 7.5 5.0
SOURCE: ASHRAE 2014 Handbook Refrigeration
NOTE: TEL values for the filter-drier and solenoid valve are already
included and should not be added to the liquid line drop.
Additional Piping Installation Guidelines
The brazed-plate evaporators have no charge and are not
sealed. A holding charge of an inert gas, such as nitrogen,
is provided for the outdoor condensing unit. Holding charges
must be evacuated prior to the R-410a charging procedure.
Interconnecting refrigerant piping and total system refrigerant
charge are field supplied and installed.
The installer must leak test the remote piping with nitrogen
at 150 psig maximum pressure, then properly evacuate the
piping system to 500 microns or below and provide the correct
operating charge of R-410a. Insulate the suction line to reduce
excessive superheat build-up. Insulate the liquid line to prevent
loss of subcooling and consequent liquid flashing.
The use of double risers for vertical gas risers is not allowed.
Size the single vertical riser per Table 6 . A small trap must be
provided at the base of each major vertical gas riser to assist in
the collection of oil. If vertical risers exceed more than 20 feet,
install a second trap per guidelines above. Follow ASHRAE
procedures and refrigerant piping guidelines. Exceeding these
recommendations will decrease performance and could impact
system reliability.
Use caution in sizing the liquid line in applications where
the evaporator is above the outdoor section. The weight of
the liquid refrigerant in the vertical column will decrease the
pressure at the top of the riser (approximately 0.5 psi per foot
of vertical rise) allowing some of the refrigerant to flash to a
gas. Adequate refrigerant subcooling is needed at the outdoor
section to prevent refrigerant gas at the expansion valve.
Care should be taken while designing piping system to avoid
the draining of condensed refrigerant to the lower component
when normal shut-down procedures do not occur (such as a
power failure).
Field Installed Component Locations
The following components must be installed adjacent to the
remote evaporator, see Figure 27 thru Figure 30 .
The expansion valves must be installed within 12 inches of
the evaporator inlet connection and the outlet piping of the
expansion valve must go directly into the evaporator with no
bends in between. See also “Wiring for Remote Evaporators”
on page 24.
The liquid line solenoid valves must be installed within 3 ft. of
the evaporator. The liquid line solenoid valve cable must be
connected to the solenoid valve using a junction box to extend
the wiring to the length required to reach the solenoid.
The liquid line filter drier must be installed at the remote
evaporator - upstream of the liquid solenoid valve and
expansion valve - as shown in Figure 27 on page 26 thru
Figure 30 on page 28.
• Install a ball valve before and after the filter drier
• Install a charging valve at the filter drier inlet between the
inlet ball valve and the filter drier
• Install a Schrader fitting after the filter drier to measure
the pressure drop across the filter drier and the liquid
subcooling leaving the filter drier.
Hot Gas Bypass Applications
Provide condenser fan VFDs for applications when operation
below 32°F ambient is expected and hot gas bypass is desired.
This is necessary to maintain adequate condensing pressures
and liquid refrigerant at the expansion valve when condenser
capacities are at their minimum.
Referencing
Figure 27 and Figure 28 for refrigerant piping
schematics, the solenoid valve and hot gas bypass valve need
to be as close to the condensing unit as possible.
If at the same elevation or if evaporator is below the
condensing unit, the hot gas bypass piping must be downward
sloping toward the evaporator with a 1 inch drop per 10 foot of
piping run in the direction of flow.
If the evaporator is above the condensing unit, add a check
valve in the hot gas bypass piping at the evaporator to prevent
refrigerant condensing in the line, which results in loss of
subcooling.