Shunt controlled
additional heat
GENERAL
This function enables an external additional heater, e.g.
an electric boiler, wood boiler, pellet boiler, oil boiler,
gas boiler or district heating, to assist with the heating.
The indoor module controls a shunt valve (EM1-QN11)
and a circulation pump (EM1-GP10) via the accessory
board in AXC 30. If the heat pump cannot maintain the
correct supply temperature, at the external supply tem-
perature sensor, (EM1-BT25), the additional heat starts.
When the boiler temperature on the boiler sensor (EM1-
BT52) exceeds the set value, the indoor module trans-
mits a signal to the shunt (EM1-QN11) to open from the
additional heat. The shunt (EM1-QN11) is regulated so
the true supply temperature corresponds with the indoor
module’s theoretical calculated set point value. When
the heating demand drops sufficiently, so that additional
heat is no longer required, the shunt (EM1-QN11) closes
completely.
Factory-set minimum operating time for the boiler is 12
hours.
The function smart energy source can be selected if you
want to prioritise automatically between heat pump
operation and additional heat versus the best price or
environmental impact.
PIPE CONNECTIONS
The external circulation pump (EM1-GP10) is placed on
the supply line to the climate system after the temper-
ature sensor (AA25-BT25)
SHUNT VALVE
The shunt valve (EM1-QN11) must be placed on the
supply line to the climate system after the heat pump
according to the outline diagram.
AB
B
A
• Connect the supply line from the
heat pump to the external heat
source via the T-pipe to port B on
the shunt valve (closes on reduce
signal).
• Connect the supply line to the climate system from
the shunt valve to the common port AB (always open)
• Connect the supply line from the external additional
heat to the shunt valve to port A (opens on increase
signal).
TEMPERATURE SENSOR
• Install the boiler sensor (EM1-BT52) in a suitable loca-
tion in the external additional heat.
• The external supply temperature sensor (AA25-BT25),
connected in the indoor module’s control module,
must be installed on the supply line to the climate
system after the shunt valve (EM1-QN11).
LEK
LEK
E
Install the temperature sensors using cable ties, together
with the heat conducting paste and aluminium tape.
Then insulate with the enclosed insulation tape.
NOTE
To prevent interference, sensor cables to ex-
ternal connections must not be laid close to
high voltage cables.
49
AXC 30 F-series | GB
F
