Viessmann VITOCAL 151-A Installation And Service Instructions Manual page 13

Intended use
(cont.)
Intended use presupposes that a fixed installation in
conjunction with permissible, system-specific compo-
nents has been carried out.
Commercial or industrial usage for a purpose other
than central heating/cooling or DHW heating shall be
deemed inappropriate.
Incorrect usage or operation of the appliance (e.g. the
appliance being opened by the system user) is prohibi-
ted and will result in an exclusion of liability. Incorrect
usage also occurs if the components in the heating
system are modified from their intended function.
Product information
Layout and functions
Vitocal 151-A is a monoblock air source heat pump,
comprising 1 indoor unit with integral DHW cylinder
and 1 outdoor unit.
Refrigerant circuit
The refrigerant circuit works with refrigerant R290 (pro-
pane).
All components of the refrigerant circuit are located in
the outdoor unit, including the refrigerant circuit con-
troller with 2 electronic expansion valves. Subject to
operating conditions, compressor output is matched
via inverter control.
To provide room cooling, there is an electronically con-
trolled reversal of the refrigerant flow direction within
the refrigerant circuit.
Hydraulics
The indoor and outdoor units are connected to each
other hydraulically.
The hydraulic components for room heating and cool-
ing are located in the indoor unit. 1 high efficiency cir-
culation pump is installed to supply the heating/cooling
circuits.
Switching between room heating, DHW heating and
defrosting is done with the integrated 4/3-way valve.
The heat required to defrost the evaporator is provided
by the integrated buffer cylinder in the indoor unit. The
overflow valve function to guarantee the minimum sys-
tem volume flow rate is also achieved via the 4/3-way
valve.
System without heating water buffer cylinder
The heat pump heats or cools 1 heating/cooling circuit
without mixer.
The flow temperature is controlled by modulating the
heat pump.
Note
The appliance is intended exclusively for domestic or
semi-domestic use, i.e. even users who have not had
any instruction are able to operate the appliance
safely.
System with external heating water buffer cylinder
The heat pump heats up to 4 heating circuits: 1 heat-
ing circuit without mixer and up to 3 heating circuits
with mixer
DHW cylinder
A 190 l DHW cylinder is integrated in the indoor unit.
Instantaneous heating water heater
In the indoor unit, an instantaneous heating water
heater is built into the heating water flow from the out-
door unit. This instantaneous heating water heater
supports the heat pump in room heating and/or DHW
heating if the heating output of the heat pump is insuffi-
cient under certain conditions. In power-OFF mode or
a fault in the heat pump, this instantaneous heating
water heater can also be switched on as the sole heat
source, e.g. for frost protection of the system, including
the outdoor unit.
Heat pump control unit
The heat pump control unit built into the indoor unit
monitors and regulates the entire heating system.
The indoor and outdoor units communicate via CAN
bus.
Information
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