Daikin LRMEQ3BY1, Installation And Operation Manual

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4 Preparation
Installation and operation manual
8
4BY1
Air-cooled refrigeration condensing unit
4P495373-1 – 2017.07
4.2.2 Refrigerant piping requirements
NOTICE
Refrigerant R410A requires strict cautions for keeping the
system clean and dry. Foreign materials (including mineral
oils or moisture) should be prevented from getting mixed
into the system.
NOTICE
The piping and other pressure-containing parts shall be
suitable for refrigerant. Use phosphoric acid deoxidised
seamless copper for refrigerant.
▪ Foreign materials inside pipes (including oils for fabrication) must
be ≤30 mg/10 m.
4.2.3 Refrigerant piping material
▪ Piping material: Phosphoric acid deoxidised seamless copper.
▪ Piping temper grade and thickness:
Outer diameter
(Ø)
Temper grade Thickness (t)
(a)
6.4 mm (1/4")
9.5 mm (3/8")
12.7 mm (1/2")
Annealed (O) ≥0.80 mm
t
Ø
15.9 mm (5/8") Annealed (O) ≥0.99 mm
19.1 mm (3/4") Half hard (1/2H) ≥0.80 mm
(a) Depending on the applicable legislation and the unit's
maximum working pressure (see "PS High" on the unit
name plate), larger piping thickness might be required.
4.2.4 To select the piping size
Determine the proper size using the following tables and reference
figure (only for indication).
F
A
1
2 3 3
d1
e
B
d2
C
c
D1
E
f
D2
b a
H
2
1 Outdoor unit
2 Indoor unit (Showcase)
3 Indoor unit (Blower coil)
A~F Liquid piping
a~f Gas piping
H Height difference outdoor-indoor
In case the required pipe sizes (inch sizes) are not available, it is
also allowed to use other diameters (mm sizes), taken the following
into account:
▪ Select the pipe size nearest to the required size.
▪ Use the suitable adapters for the change-over from inch to mm
pipes (field supply).
▪ The additional refrigerant calculation has to be adjusted as
mentioned in "5.5.2 To determine the additional refrigerant
amount" on page 15 .
A/a: Piping between outdoor unit and piping
branching
Liquid piping Ø9.5 mm
(a)
Gas piping Ø19.1 mm (b)
(a) Same diameter as the connection on the outdoor unit.
(b) Use the accessory piping to adapt the diameter of the
outdoor unit stop valve (Ø15.9 mm) to that of the field
piping (Ø19.1 mm).
B+C/b+c: Piping between piping branching
Use diameters depending on the total capacity of the indoor units
connected downstream.
Capacity Piping outer
diameter
Liquid piping <4.0 kW Ø6.4 mm
4.0≤x<8.4 kW Ø9.5 mm
Gas piping <1.0 kW Ø9.5 mm
1.0≤x<6.0 kW Ø12.7 mm
6.0≤x<8.4 kW Ø15.9 mm
D~F/d~f: Piping between piping branching and
indoor unit
Use the same diameters as the connections (liquid, gas) on the
indoor units.
NOTICE
If only 1 indoor unit is connected to the outdoor unit, and
the connections on the outdoor unit are different from
those on the indoor unit, then use the same piping
diameter as the connections on the outdoor unit, and install
suitable adapters as near to the indoor unit as possible.
4.2.5 To select refrigerant branch kits
For refrigerant piping branching, it is allowed to use T-joints, Y-joints,
refnet joints, and refnet headers. It is possible to use a refrigerant
branching option kit from the table below.
Description Model name
Refnet header
(a)
KHRQ22M29H
Refnet joint
(b)
KHRQ22M20T
KHRQ22M29T9
(a) Do NOT connect 2 or more headers in series. For the gas
side choose the refnet header so that the diameter of the
header is equal to the main piping diameter or equal to one
size-up of the main piping diameter.
(b) Choose the refnet joint so that the incoming and outgoing
piping diameters match with one of the available diameters
of the refnet joint. For more information, see
"4.2.3 Refrigerant piping material" on page 8 and
"4.2.4 To select the piping size" on page 8 .
INFORMATION
Maximum 8 branches can be connected to a header.
4.2.6 To select the expansion valve
This unit has a larger subcooling ratio for the liquid refrigerant
compared to units without a subcooling mechanism, as the liquid
refrigerant is being cooled by a double tube heat exchanger
(subcooling ratio = condensing temperature
– liquid refrigerant
temperature at outdoor unit outlet).
When selecting an expansion valve for the load according to the
technical information of the expansion valve manufacturer, take into
account the subcooling ratio (K) for the liquid refrigerant in the table
below.