Blue Box SIGMA 2002, Installation, Installation, Operating, Operating, And Maintenance Manual

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Blue Box - 29
4.4 EVAPORATOR WATER PIPE CONNECTIONS
The water inlet and outlet must be connected in the positions indicated
as labelled on the unit.
A constant water flow to the evaporator must be guaranteed at all
operating conditions to prevent liquid refrigerant from entering the
compressor and causing irreparable damage.
Compressors start and stop often due to changes in cooling demand. In hydraulic circuits with low water volume,
where the thermal inertia action is low, it is advisable to verify that the water volume equals or exceeds the
following ratio:
24 · Q
COMPTOT
M>= ---------------------
N
where:
M = system water content [kg]
Q
COMPTOT
= unit cooling capacity [kW]
N = number of capacity steps
If the water volume does not reach the value given by the formula, it is advisable to provide the circuit with a
storage vessel to increase the volume (tank + circuit) to match the result of the formula.
The chilled water piping and storage vessel must be insulated to prevent condensation on the pipe surfaces and
to avoid circuit performance losses.
On all units it is compulsory to install a flow switch. If a flow switch is not
installed, on the evaporator leaving water connection, the warranty will
be terminated immediately.
The flow switch must be installed, by the
contractor, on the evaporator water outlet connection labelled with:
If incorrectly connected the antifreeze thermostat will not operate and the evaporator may freeze.
The hydraulic connections are threaded. The type and size are indicated on the dimensional drawings at the end
of this manual.
HEAT PUMP units require a second flow switch is provided with the unit.
This must be installed, by the contractor, on the condenser outlet
connection labelled with:
CONDENSER WATER
EVAPORATOR WATER
EVAPORATOR WATER