Hydronic Connections; Frost Protection - Carrier AQUASNAP 30RA B Series Manual

9.2 - Hydronic connections

The diagram on the next page shows a typical hydronic
installation.
When charging the water circuit use air vents to evacuate any
residual air pockets.

9.3 - Frost protection

The plate heat exchangers, the piping and the hydronic module
pump can be damaged by frost, despite the built-in anti-freeze
protection of the units.
The frost protection of plate heat exchanger and all hydronic
module components is guaranteed down to -20°C by auto-
matically energized heaters and pump cycling.
Never switch off the evaporator and hydronic circuit heaters or
the pump, otherwise frost protection cannot be guaranteed.
For this reason the main unit disconnect switch (QS101) as
well as the auxiliary protection switch (QF101) for the heaters
must always be left closed (for location of QS and QF 101 see
wiring diagram).
To ensure frost protection down to -20°C, water circulation in
the water circuit must be maintained by periodically switching
on the pump. If a shut-off valve is installed, a bypass must be
included as shown below.
Winter position
A
Legend
A Unit
B Water network
C Closed
O Open
20
F
F
O
IMPORTANT:
Depending on the atmospheric conditions in your area you
must do the following when switching the unit off in winter:
- Add ethylene glycol with an adequate concentration to pro-
tect the installation up to a temperature of 10 K below the
lowest temperature likely to occur at the installation site.
- If the unit is not used for an extended period, it is
recommended to drain it, and as a safety precaution
introduce ethylene glycol in the heat exchanger, using
the water entering purge valve connection.
At the start of the next season, refill the unit with water
and add an inhibitor.
- For the installation of auxiliary equipment, the installer
must comply with basic regulations, especially for
minimum and maximum flow rates, which must be
between the values listed in the operating limit table
(application data).
- To prevent corrosion by differential aeration, the complete
drained heat transfer circuit must be charged with
nitrogen for a period of one month. If the heat transfer
fluid does not comply with the Carrier S.A. regulations,
the nitrogen charge must be added immediately.
B