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INSTALLATION
The power supply cable must be routed through one of the dedicated holes located on the left or right side of the machine, after removing the
pre-cut part from the selected hole.
Connect the cable to the terminals inside the electrical panel by passing it through the appropriate cable glands in the lower part of the panel.
Auxiliary connection terminal board
(The configuration of the electrical panel can change slightly depending on the size)
After approximately 10 minutes of operation of the heat pump, check the tightness of the screws on the power supply
terminal board.
The numbering of the terminals can change without notice. For the connections it is therefore ALWAYS necessary to refer to
the wiring diagram supplied with the unit.
4.17.2
Connections of the temperature probes
The unit is supplied with the following probes connected to the terminal board which must be positioned on site during installation.
Ref.
Terminals
Description
Notes
BT1
F
loor probe
It is used to control the YV3 system mixer. It must be positioned on the delivery to the utility
downstream of the valve.
If the mixer control is not activated, the BT1 probe is used as an input probe to the
geothermal heat exchanger, so it must be positioned in the well arranged on the upper
connection of this component.
BT2
Domestic hot water
storage probe (only
in versions /R)
It is used to manage the operation in domestic hot water and heat recovery modes. It should
be placed in a well installed on the domestic hot water storage.
The temperature read by the probe must be close to the average temperature in the tank:
the well must be placed at a height of between ¼ and ½ and must have a length such as to
arrive near the axis. The probe must not be struck by water flows at low or high temperature
and must not be close to heat exchangers or heaters.
If the unit controls an additional heat source, the probe must be positioned higher than it.
BT3
External air sensor
It is used to read the finalised external air temperature, for example to automatically correct
the set points of the unit or of the mixing valves (if managed).
The sensor must be positioned such that it detects the temperature of the outside air and
must not be influenced by factors that could distort the reading (for example direct sunlight,
other heat sources, snow/ice accumulations). As the external air sensor is supplied without
protection, it is advisable to provide a protective container.
BT4
Regulation probe
(utility return)
It reads the temperature of the water entering the utility exchanger that is used to manage
operation of the heat pump. In the factory it is placed in a pit on the lower connection of
the exchanger.
This probe can be moved to a well mounted on the utility storage tank. In this way it is
possible to make the utility pump not work when the compressor is in stand-by.
The indications for correct positioning are the same as those given for the BT2 probe.
Rev. C 09-2020
MTEC.3810.GB-C-1 Operation and maintenance manual serie WZA English
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