Mitsubishi Electric EHST20-Serie Installationshandbuch Seite 30

5
System Set Up
Mode 1 - domestic Hot Water (dHW)/legionella Prevention
The domestic hot water and legionella prevention menus control the operation of
domestic hot water tank heat ups.
<dHW mode settings>
. Highlight the hot water icon and press CONFIRM.
2. Use button F to switch between Normal and ECO heating modes.
3. To edit the mode press F2 to display the HOT WATER (DHW) SETTING menu.
4. Use F2 and F3 keys to scroll through the menu selecting each component in
turn by pressing CONFIRM. See the table below for description of each setting.
5. Enter the desired number using the function keys and press CONFIRM.
Menu subtitle Function
DHW max. temp Desired temperature of stored hot water
DHW max. temperature Difference in temperature between DHW max. temp and the temperature at which DHW mode starts
drop
DHW max. operation time Max time allowed for stored water heating DHW mode
DHW mode restriction The time period after DHW mode when space heating has priority over DHW mode temporarily
preventing further stored water heating
(Only when DHW max. operation time has passed.)
<explanation of dHW operation>
• When the tank temperature drops from "DHW max. temp" by more than the "DHW
max. temperature drop" (set by installer), DHW mode operates and the flow
from the primary heating circuit is diverted to heat the water in the storage tank.
• When the temperature of the stored water reaches the 'DHW max. temp.' set by
the installer or if the 'DHW max. operation time' set by the installer is exceeded
DHW mode ceases to operate.
• Whilst DHW mode is in operation hot water is not directed to the space heating
circuit.
• Directly after DHW max. operation time 'DHW mode restriction' will operate.
The duration of this feature is set by the installer and during its operation DHW
mode can not be reactivated, allowing time for the system to deliver hot water
to the space heating if required.
• After the 'DHW mode restriction' operation the DHW mode can operate again
and tank heating will continue according to system demand.
<eco mode>
DHW mode can run in either 'Normal' or 'Eco' mode. Normal mode will heat the
cylinder quickly using the full power of the heat pump. Eco mode takes a little
longer to heat the cylinder but the energy used is reduced. This is because heat
pump operation is restricted using signals from the FTC3 based on measured
cylinder temperature.
note:
the actual energy saved in eco mode will vary according to outdoor tem-
perature.
Return to the DHW/legionella prevention menu.
legionella Prevention Mode settings (lP mode)
1. Use button F3 to chose legionella mode active YES/NO.
2. Use button F4 to edit the legionella function.
3. Use F2 and F3 keys to scroll through the menu selecting each subtitle in turn by
pressing CONFIRM. See the table below for description of each setting.
4. Enter the desired number using the function keys and press CONFIRM.
During Legionella Prevention Mode the temperature of the stored water is increased
above 60°C to inhibit legionella bacterium growth. It is strongly recommended that this is
done at regular intervals. Please check local regulations for the recommended frequency
of heat ups.
Note: When failures occur on the cylinder unit, the LP mode may not function normally.
Menu subtitle Function
Hot water temp. Desired temp of stored hot water
Frequency Time between LP mode tank heat ups
Start time Time when LP mode will begin
Max. operation time Maximum time allowed for LP mode tank heat
Duration of max. temp. The time period after LP mode max. water temp has been reached
29
Tank temp.
Stop
DHW max.
temp.
DHW max.
temp.drop
Start
DHW mode
Tank temp.
DHW max.
temp. Stop
DHW max.
temp. drop
Start
DHW max. DHW mode
operation time
restriction
range
60–70
–30
0:00–23:00
–5
–20
range Unit default value
40–60 °C 50
5–30 °C 0
30–20 min 60
30–20 min 30
Restart
Time
DHW mode
Stop
Restart
Time
DHW mode
Unit default value
°C 65
day 5
- 03:00
hour 3
min 30