Carrier AQUASNAP JUNIOR 30RA015, Данные о продукции, Страница: 25 / 48

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Expansion tank selection and filling
Expansion tanks are essential to the operation of any
closed, pressurized, hydronic system. They perform four
important functions: 1) provide for expansion of the liquid
as the temperature in the system rises, 2) act as a pressure
reference for the system, 3) supply sufficient pressure to
prevent cavitation, 4) provide a location to charge the
system.
The AquaSnap ® optional hydronic package includes a
bladder-style expansion tank, pre-charged to 40 psig
(277 kPa) pressure and pre-selected for loop volumes up to
6 gallons per ton. If loop volumes in excess of those indi-
cated in the loop volume chart on page 43 are required,
then a field-installed expansion tank must be provided, and
the expansion tank in AquaSnap hydronic package must
be removed.
If the top of the piping system (the highest point in the
hydronic piping) is more than 80 ft (12.2 m) above the
chiller, then the expansion tank will require additional air
pressure charge. The expansion tank must be pressurized
to provide at least 4 psig (28 kPa) of positive pressure at
the highest point in the hydronic piping system. This will
also ensure no air is drawn into the piping. The amount of
charge pressure in pounds per square inch (psi) that is
required in the expansion tank is equal to 4 psig (28 kPa)
plus the height (in feet) from the chiller to the highest point
in the hydronic system divided by 2.31.
Example: The 30RA AquaSnap elevation is 10 ft (3.1 m).
The hydronic system is piped to an air handler on the roof
with an elevation of 100 ft (30.5 m). The total pressure
required in the expansion tank is:
4 psig + (100 ft – 10 ft)/2.31 = 42.96 psig
28 kPa + (30.5 m – 3.1 m)/0.102 = 296 kPa
The expansion tank will require an additional 3 psig
(19 kPa) of pressure.
30RA010-030 PUMP ENVELOPES
30RA035-055 PUMP ENVELOPES
NOTES:
1. Refer to Position 9 in the unit’s model num b er for pump identification.
2. To convert gpm to L/s, multiply b y 0.063. To convert head pressure to
kPa, multiply b y 2.986.