Hitachi RWM-(H)FSN3E, Service Manual

Page: 169 / 424

5 Control system
SMGB0070 rev. 1 - 08/2011
159
5
Setting the solar status
This default setting can be changed, so that at all times, when solar heat becomes available, domestic water heating by
the heat pump will be (if busy) interrupted and taken over by the sun.
CODE Description Default Value
10-001 Solar status (Disabled, Enabled) Disabled
Solar enabling/disabling conditions
• Solar start conditions
When all of Conditions a, b, c, d, are fulfilled.
a.
Solar status enabled by user
b. Solar energy available through solar pump station (Input Terminal 10 enabled)
c. T
DHW
< T
DHWS
- T
DHWON
Where:
T
DHW
= Domestic Hot Water Tank temperature (ºC)
T
DHWS
= Domestic Hot Water Tank temperature setting (ºC) (Default 45ºC)
T
DHWON
= Domestic hot water differential ºC (temperature drop that starts DHW) (Default 10ºC)
T
DHWMAX
= Domestic Hot Water tank maximum supply temperature (ºC) (Default 70 ºC)
If conditions are fulfilled, heating DHW by Heat Pump will be switched OFF, and heating will be done by solar station
through YUTAKI S’s auxiliary output signal. If T
DHW
> T
DHWMAX
solar station cannot heat DHW by tank at maximum allowed
temperature and YUTAKI S’s auxiliary output will be switched OFF.
• Solar stop conditions
When any of Conditions e, f, g, h is fulfilled.
d.
Solar status disabled by user
e. Solar energy not available through solar pump station (Input Terminal 10 disabled)
f. T
DHW
> T
DHWS
g. T
DHW
> T
DHWMAX
N O T E
When heating DHW by solar power, DHW Timer has no effect.