Dunham-Bush WCFX 10, Installation, Operation & Maintenance Manual

Page: 5 / 64

126"
[3200mm]
42" [1067mm]
IF EVAPORATOR
IS INSULATED
FLAP MUST
BE RAISED
TO EXPOSE
LIFTING HOLE
SPREADERS
LIFT LIFT
1
.
0
GENERAL INFORMATION
1.4.3
Water Cooled Condensers
The water-cooled condenser is also
designed for constant water flow rate,
and should be supplied with the design
GPM [m³/hr] ±10%. The condenser must
be protected from rapid changes in
temperature as well. The maximum
allowable rate of change in condenser
entering water is 1°F [0.6°C] per minute.
Fluctuating flow rate or temperature will
cause unstable control of the machine,
resulting in poor control of leaving
chilled water temperature. If a cooling
tower is used to reject heat from the
condensing water loop, it must be
controlled to provide an entering
condensing water temperature which
does not change more rapidly than 1°F
[0.6°C] per minute and does not go
below 60°F [15.6°C]. One or more of the
following methods may be used to
control the tower:
1.4.3.1
A modulating three-way valve
which bypasses tower sprays
at low load and low ambient
temperature.
1.4.3.2
Tower fan staging in response
to a thermostat in the tower
sump. Fan thermostat should
have a differential of at least
20°F [11.1°C] to avoid short
cycling.
1.4.3.3
A modulating three-way valve
which bypasses the cooling
tower to blend warm leaving
condenser water with cold
tower water.
1.4.4 Condensing Water
Treatment
Condensing water tends to leave silt,
algae and mineral deposits in the
condenser tubes. This fouling gradually
decreases unit efficiency. For this reason,
a program of water treatment should be
employed. Also, at regular intervals
depending on water quality, the unit
should be shut down, condenser heads
removed and tubes cleaned. See Section
5.4.
FIGURE 1.2 RIGGING DIAGRAM
Rigging should be done in a manner so that no strain is placed on unit components other than at cable
connection points
WCFX 10, 12, 15, 18
Note: Project unit from cables.
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