Nibe AXC 50, Installer Manual

Page: 6 / 48

General
This connection enables an external additional heater,
e.g. an oil boiler, gas boiler or district heating exchanger
to aid with heating.
The heat pump controls a shunt valve and a circulation
pump via AXC 50. If the heat pump cannot maintain the
right flow temperature the additional heating starts.
When the boiler temperature has been increased to about
55 ° C, the heat pump sends a signal to the shunt (QN11)
to open from the addition. The shunt (QN11) adjusts so
the true flow temperature corresponds with the control
system’s theoretical calculated set point value. When the
heating requirement drops sufficiently so the additional
heat is no longer required the shunt (QN11) closes com-
pletely. Minimum connection time for the boiler is 12
hours.
Pipe connections
The external circulation pump (GP10) is positioned accord-
ing to the outline diagram.
Shunt valve
The shunt valve (QN11) is located on the flow line to the
climate system after the heat pump according to the
outline diagram.
AB
B
A
႑ Connect the flow line from the heat
pump to the external heat source via
the T-pipe to port B on the shunt
valve (closes at reduced signal).
႑
Connect the flow line to the climate
system from the shunt valve to the
common port AB (always open)
႑
Connect the flow line from the external additional heat
to the shunt valve to port A (opens at increased signal).
Temperature sensor
႑
Install the boiler sensor (BT52) in a suitable location in
the external addition.
႑
External flow temperature sensor (BT25, connected in
F1345) must be installed on the flow line to the radiat-
ors, after the shunt valve (QN11).
K
Install the temperature sensors with cable ties with the
heat conducting paste and aluminium tape. Then insulate
with supplied insulation tape.
NOTE
Sensor and communication cables must not be
placed near power cables.
AXC 50 Chapter 3 | Shunt controlled additional heat 4
3 Shunt controlled additional heat