Daikin WGZ030DA, Инструкция по установке, эксплуатации и обслуживанию

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www.DaikinApplied.com 15 IOM 1322 • WATER-COOLED SCROLL COMPRESSOR
ASHRAE standards. If the velocity in a vertical discharge
riser is too low, considerable oil can collect in the riser and
the horizontal header, causing the compressor to lose its oil
and result in damage due to lack of lubrication. When the
compressor load is increased, the oil that had collected during
reduced loads can be carried as a slug through the system
and back to the compressor, where a sudden increase of oil
concentration can cause liquid slugging and damage to the
compressor.
Any horizontal run of discharge piping should be pitched away
from the compressor approximately 1/8 inch (6.4 mm) per foot
(meter) or more. This is necessary to move, by gravity, any oil
lying in the header. Oil pockets must be avoided because oil
needed in the compressor would collect at such points and the
compressor crankcase can become starved.
It is recommended that any discharge lines coming into a
horizontal discharge header rise above the centerline of the
discharge header. This is necessary to prevent any oil or
condensed liquid from draining to the compressor heads when
the compressor is not running.
In designing liquid lines, it is important that the liquid reach the
expansion valve without flash gas since this gas will reduce
the capacity of the valve. Because “flashing” can be caused
by a pressure drop in the liquid line, the pressure losses due
to friction and changes in static head should be kept to a
minimum.
A check valve must be installed in the liquid line in all
applications where the ambient temperature can drop below
the equipment room temperature and there is not a natural
drain. In cases where the liquid line doesn’t have natural drain
capability, this valve prevents liquid migration to the condenser,
helps maintain a supply of refrigerant in the liquid line for initial
start-up, and keeps liquid line pressure high enough on “off”
cycle to keep the expansion valve closed.If a check valve is
necessary, there must also be a bypass relief valve to prevent
hydrostatic pressure failure.
Install a relief device in the hot gas piping at the condenser coil
as shown in Figure 7 and Figure 8 . Install a discharge check
valve in the discharge line, in a horizontal run, close to the
condenser.
Refrigerant Piping
New refrigerant piping must be used for all equipment
installations. Refrigerant piping must be properly sized for
the circuit capacity and unit refrigerant. Piping system must
be brazed and have the proper lay out with all required
components.
Guidelines for Field Piping
Final design should be based on ASHRAE design standards.
For installations where the condenser is installed above the
unit ( Figure 7 ), the following recommendations apply:
• 30 ft. maximum vertical distance
• Only single riser suction tubing is to be used - double
riser installations are not permitted
• A discharge line trap must be installed at the bottom of
the riser and a second trap at 20ft. height.
Table 1: Remote Condenser Piping Limitations
Maximum measured piping distance between the
unit and the remote condenser
90 ft.
Maximum equivalent Feet of Distance between the
unit and the condenser including elbows and traps
150 ft.
NOTE: For installations Daikin Applied Technical Response
Center (TRC) must be consulted for approval of the
piping design for factory warranty to be valid.
IMPORTANT NOTE
Service Form SF99006 (current version available from the local sales office)
must be submitted to Daikin Technical Response Center and reviewed at
least two weeks prior to beginning piping installation.
Table 2: Equivalent Feet for Fittings
Table 3: Maximum Line Size for Oil Carry Up a Discharge
Riser, R-410A
Refrigerant Piping