Pressure Drop - Hitachi RAS-H(V)RNME-AF Service Manual

3 Piping work and
refrigerant charge

3.4.2 Pressure drop

DHWT(200/300)E-2.5H1E
500
200
100
50
20
10
5
0.2 0.5
0

General standard for hydraulic installation
- The safety valve unit will fitted at the sanitary water installation.
- A pressure reducer must be placed in the DHWT installation. The nominal pressure of the safety unit will be 8 bar.
- When the main pressure is more than 6 bar a pressure reducer should be installed.
- The water discharge during heating (expansion) is normal. The volume of this discharge can be up to 3% of the
storage tank's capacity.
- The pressure regulator device must be working regularly , depending on the quality of water, in order to remove the
lime's deposits and verify that it is not blockade.
- A water leakage in the pressure protection device can exist. The discharge pipe should be always open to the at-
mosphere, free of frost and in continuous slope to the down side.
- Dielectric bushes must be fitted at the input and output sanitary water and at the tank circuit connections.
Emptying the DHWT: Close the main inlet water valve and open the relief valve of the security water group.
-
74
SMGB0070 rev.1 - 08/2011
2 5
1 10 C m
=
p
DHWT(200/300)S-2.5H1E
500
200
100
50
20
10
5
0.2 0.5
3 /h
0
Ref Name

Main inlet water

DHWT inlet connection

Security valve and manual empty

Emptying connection
 Check valve
 Close valve
2 5
1 10 C
=
p
m 3 /h