Daikin EWAT016CZN-A1, Installation, Maintenance And Operation Manual, Page: 13 / 30

EWYT~CZ / EWAT~CZ DEIMHP0140521_00EN
13
Legend:
a
. Shut-off valve
b . Water filter
c
. Threaded connector
N.B. The hydraulic elements
are supplied together with the
unit and are located inside the
cabinet.
4.8. Water treatment
Before putting the unit into operation, clean the water circuit.
The BPHE must not be exposed to flushing velocities or debris
released during flushing. It is recommended that a suitably sized
bypass and valve arrangement is installed to allow flushing of the
piping system. The bypass can be used during maintenance to isolate
the heat exchanger without disrupting flow to other units.
Any damage due to the presence of foreign bodies or debris in
the BPHE will not be covered by warranty.
Dirt, scales, corrosion
debris and other material can accumulate inside the heat exchanger
and reduce its heat exchanging capacity. Pressure drop can increase
as well, thus reducing water flow. Proper water treatment therefore
reduces the risk of corrosion, erosion, scaling, etc. The most
appropriate water treatment must be determined locally, according to
the type of system and water characteristics.
The manufacturer is not responsible for damage to or malfunctioning
of equipment caused by failure to treat water or by improperly treated
water. In the following table are listed the acceptable water quality
limits:
DAE Water quality requirements BPHE
Ph (25 °C) 7.5 – 9.0
Electrical conductivity [μS/cm] (25°C) < 500
Chloride ion [mg Cl / l]
< 70 (HP
1
);
< 300 (CO
2
)
Sulphate ion [mg SO
4
2
/ l] < 100
Alkalinity [mg CaCO
3
/ l] < 200
Total Hardness [mg CaCO
3
/ l] 75 ÷ 150
Iron [mg Fe / l] < 0.2
Ammonium ion [mg NH
4
+ / l] < 0.5
Silica [mg SiO
2
/ l]
Chlorine molecular (mg Cl
2
/l) < 0.5
Note: 1. Heat Pump
2. Cooling Only
Table 5 – Acceptable water quality limits
4.9. Water pressure drops for filters
In the following figure the water filter pressure drops are illustrated.
0
10
20
30
40
50
60
70
80
90
0 1 2 3 4 5 6 7
External pressure head [kPa]
Water flow [l/s]
Water filter pressure drops
MONO CIRCUIT DUAL CIRCUIT
1'' 1/4
2''
Figure 9 – Water filter pressure drops
4.10. Pump kit mounted on board (Optional)
Before to starting up the pump, ensure that the hydraulic circuit is
filled correctly with a minimum static pressure of 1 bar as protection
from cavitation. Furthermore, to ensure correct venting of the piping
system make sure the venting valve indicated on the hydraulic
diagrams with the letter “h”, is open.
In the following figure are illustrated the External pressure head (KPa)
in case of Low lift and High lift pump.
EWA(Y)T-CZP – Pump Low lift
0
50
100
150
200
250
300
350
0 1 2 3 4 5 6 7
External pressure head [KPa]
Water flow [l/s]
C
D
E
F
A
B
Figure 10 – External pressure head of Low Lift Pump
EWA(Y)T-CZH – Pump High lift
0
100
200
300
400
500
600
0 1 2 3 4 5 6 7
External pressure head [KPa]
Water flow [l/s]
A
B
C
D
E
F
Figure 11 – External pressure head of High Lift Pump
External static pressure refers to unit equipped with hydronic kit,
defined as difference between pump external static pressure and
evaporator and water filter pressure drop. Water flow range refer to
pump only. For water flow limits of the unit refer to water flow section.