CTC Union EcoZenith i555 Pro 1x230V, Installation And Maintenance Manual

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CTC EcoZenith i555 Pro
Schematic diagram only the installer adds expansion vessels, safety valves, etc., and sizes the system.
2.10 External buffer
The EcoZenith can be connected to one or more buffer tanks. This is mainly
used when connecting wood and solar energy systems where the volume in
the EcoZenith is not suffi cient. Via the accessory “Charging External Buffer
Tank”, warm water can be sent both from the lower tank to the buffer tank(s)
and from the buffer tank(s) back to the EcoZenith. In other words, both
charging and recharging of the energy are possible.
Also refer to the "HP charging" section in the "Installer/Settings/External
Buffer Tank" chapter.
2.10.1 Solar Operation Control
When solar energy is activated, the transfer to the buffer tank(s) is performed
in two ways depending on whether heating is needed for the heating circuit.
When heating is not needed for the heating circuit, the sun charges the
EcoZenith in order to achieve a high temperature and a large quantity of
DHW. The solar panels charge the EcoZenith until the lower tank sensor
reaches the factory-set 80 °C before the circulation pump starts up and
transfers hot water from the EcoZenith connection in the lower tank to the top
of the fi rst buffer tank. Charging continues until the sensor in the lower tank
has fallen 3 degrees (transfer starts at 80 degrees and stops at 77 degrees).
The lower tank must be at least 7 degrees warmer than the buffer tank for
charging to be allowed to start. This applies independently of whether there is
a need for heating or not.
When there is a need to heat the house, the transfer will be controlled by
the reference value (setpoint) in the lower tank. When the sun has heated
the lower tank to 7 degrees above the reference value, the transfer starts,
provided that the lower tank is also 7 degrees warmer than the buffer tank.
Effi ciency of the solar panels increases when they work towards a low water
temperature, which is the case in spring and autumn, as there is no great
need for heating during either of these seasons. The temperature levels
stated above can be adjusted.