Mitsubishi Electric ecodan EHPT20Q-VM2EA Operation Manual page 6

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The domestic hot water menu controls the operation of thermal store tank heat - ups.
1. To edit the mode, press down the MENU button for 3 secs, then select "hot
water".
2. Press F2 key to display the HOT WATER (DHW) SETTING menu.
3. Use F1 and F2 keys to scroll through the menu selecting each component
in turn by pressing CONFIRM. See the table below for description of each
setting.
4. Enter the desired number using the function keys and then press CON-
FIRM.
DHW supply max. temp. *1 Desired temperature of supply hot water
DHW supply max. temp. drop Difference in temperature between DHW supply max. temp. and DHW
supply min. temp.
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.)
DHW storage volume *2 The amount of stored hot water. DHW max. amount and DHW restart
amount can be selected. (See Figure 4.1)
*1 Depending on the ambient conditions, it may possibly not reach the set temperature.
*2 Selection of E. Save will increase efficiency of operation. However, it should NOT be selected if there is concern about possible shortage of DHW
provision.
.
When the DHW storage volume shows a decrease of 50 L from
the DHW max. amount, DHW mode operates and the flow from
the primary heating circuit is diverted to heat the water in the ther-
mal store tank.
When the amount of the stored hot water reaches the 'DHW max.
amount *1 .' or if the 'DHW max. operation time' set by the installer
is exceeded DHW mode ceases to operate. (See Figure 4.2)
*1 The DHW max. amount is 200L when the DHW storage volume set by the
installer is 'normal' and 150L when it is 'Energy save'.
Whilst DHW mode is in operation primary hot water is NOT
directed to the space heating circuit.
Directly after DHW max. operation time 'DHW mode restriction'
will routinely operate. The duration of this feature is set by the
installer and during its operation, DHW mode can not (normally)
be reactivated, allowing time for the system to deliver primary hot
water to the space heating if required. However,if at this time
there is no current demand for space heating, the system will au-
tomatically resume DHW mode. This will continue until the unit
receives a demand for space heating. (See Figure 4.3)
After the 'DHW mode restriction' operation the DHW mode can
operate again and thermal store tank heating will continue ac-
cording to system demand.
10
R
40 - 70 °C 55
15 - 30 °C 15
30 - 120 min 60
30 - 120 min 30
Normal / − Normal
E. Save
DHW max. amount 150L 200L
DHW restart amount 100L 150L
<Figure 4.1>
Stop
DHW max.
amount
Restart
DHW restart
amount
Start
T
DHW mode DHW mode
<Figure 4.2>
Stop
DHW max.
amount Restart
Stop
DHW restart
amount
Start
T
DHW max. DHW mode
DHW mode
operation time restriction
<Figure 4.3>
4 Customizing Settings for Your Home
Forced DHW
The Forced DHW function is used to force the system to operate in DHW mode. In normal operation the water in the
thermal store tank will be heated either to the set temperature or for the maximum DHW time, whichever occurs first.
However should there be a high demand for hot water 'Forced DHW' function can be used to prevent the system from
routinely switching to space heating and continue to provide DHW tank heating.
Forced DHW operation is activated by pressing button F1 and Back button in the 'Option Screen' . After Forced DHW
operation finishes, the system will automatically return to normal operation. To cancel forced DHW operation hold
down button F1 in the 'Option Screen'.
The heating menus deal with space heating normally using either a radia-
tor, fan-coil, or underfloor heating system depending on the installation.
There are 3 heating modes
Heating room temp. (Auto adaptation) ( )
Heating flow temp. ( )
Heating compensation curve ( )
To edit compensation mode, press down the MENU button for 3 secs.
This mode is explained in detail in 'Overview of Controls' Section (page 5).
The temperature of the water flowing to the heating circuit is set by the installer
to best suit the space heating system design, and user's desired requirements.
During late spring and summer usually the demand for space heating is natu-
rally reduced.To prevent the heat pump from producing excessive flow
temperatures for the primary circuit, the compensation curve mode can be
used to reduce flow temperatures, maximise efficiency and reduce running
costs.
The compensation curve is used to adjust the flow temperature of the primary
space heating circuit dependent on the outdoor temperature. The FTC uses
information from both an outdoor temperature sensor and a temperature
sensor on the primary circuit, supply to ensure the heat pump is not producing
excessive flow temperatures if current weather conditions do not require it.
Your installer will set the parameters of the graph depending on local condi-
tions and type of space heating used in your home. It should not be necessary
for you to alter these settings. If however you find that over a reasonable trial
operating period the space heating is not heating or is overheating your home,
please contact your installer so they can check your system for any problems
and update these settings if necessary.
: Flow temp.
: Outdoor ambient temp.
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