Hitachi RAS-H(V)RNME-AF Service Manual page 168

5 Control system
Solar installation requirements
• Electrical connection
The solar pump station have an auxiliary contact that closes when the operation station it is working to heat the domestic
hot water tank operated.
L N R
L N
When solar mode is enabled by the heat pump and the temperature of the glycol solution in the solar panel has risen above
the water temperature in the domestic hot water tank, one of the HP's outputs will be switched ON (terminals 25/26).
25 26
Solar station control
If the solar pump station has an ON/OFF/AUTO function, make sure to put it on the AUTO function. This means that the
pump will switch ON automatically when the solar panel temperature rises sufficiently above the domestic hot water tank
temperature and switch OFF automatically when the difference between the solar panel and the domestic hot water tank
temperature becomes too low.
When the temperature of the solar panel reaches 10°C* higher than the domestic hot water tank temperature, the pump of
the solar pump station and the pump of the solar kit will start operation.
Solar delta T
When the temperature of the solar panel becomes lower than the domestic hot water tank temperature, the pumps from
the solar pump station and the solar kit will stop operating.
158
SMGB0070 rev. 1 - 08/2011
N 1 2
Solar Pump station
Terminal Board
YUTAKI S Unit
Description Ideally Value Remarks
10 Depending on solar station
7 10
Terminal Board
YUTAKI S Unit
Auxiliary water pump
for Option 1
Solar 3-way valve for
Option 2