E-
18
The water volume and expansion vessel pressure
The unit is equipped with an expansion vessel of 8 litres which has a default pre-pressure of 1 bar.
To ensure correct operation of the unit, the pre-pressure of the expansion vessel might need to be adjusted
and the minimum and maximum water volume must be checked.
To secure enough water flow rate, set water pump
speed as “Max.”.
The standard pressure drop of the unit is
30~35 kPa.
When it’s needed to get additional E.S.P(external
pressure drop) according to field piping works,
connect additional pumps(RS25/8) on the field
piping line in series.
If the pressure loss of total system is over 54kPa,
additional water pump should be installed in
series.
Otherwise, the water flow rate might be decreased,
causing insufficient heating or cooling.
Pre-pressure is adjusted by the total water volume.
0 0.5
0.5
1
1.5
2
2.5
3
3.5
4
4.5
5
5.5
6
6.5
7
7.5
8
1 1.5 2 2.5 3 3.5 4 4.5 5
6 [m
3
/h]
5.5
H
yd
ra
ul
ic H
ea
d L
os
s(
m
H
2
O
)
Water Flow Rate
Head
m
ax.
Norminal
54 kPa
46 LPM
Operating range
0
0
2
4
6
8
10
12
14
16
18
1000
2000
3000
4000
5000
6000
Q (L/h)
H (
m
CE
)
1# pump
4# pump
1#+4# in series
Head
Norminal
In Series
46 LPM
54 kPa
108 kPa
2.5
2.0
1.5
1.0
0.5
0.0
150
200
250
300
350
Total water volume(ℓ)
Pr
e-
p
re
ss
ur
e(
ba
r)
Operation range
Pipe work (Continued)
NH080PHXEAHydro unit_IM_E 32659-1.indd 18
2010-07-28 ｿﾀﾈﾄ 8:59:26
