Application parameters – ClimaCool IOM AR2 SERIES User Manual
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THE CLIMACOOL MODULAR CHILLER -
APPLICATION PARAMETERS
Remote Condenser Control Panels Factory assembled fan cycling
control panels are available to cycle fans for head pressure
control either on ambient temperature or condensing pressure .
Contact ClimaCool for Custom applications for fan speed control
or custom built control panels .
• All fans are cycled with contactors .
• Condensers with a single row cycle fans separately with one
contactor per fan (e .g . Model #RC1-08A) .
• Condensers with two rows of fans will have each row of fans
dedicated to one specific refrigeration circuit . Since the fans
closest to the header end of the unit run continuously, the
second fan in each row will cycle independently to control
head pressure corresponding to the circuit it serves .
• Standard control circuit voltage is 24 volts . Optional Control
circuit voltages of 230 or 115 volts are available on request .
• Standard control circuits require an external power supply for
powering control circuit (by others) .
• Optional factory mounted control circuit transformer is
available on 460 volt condenser fan motor voltage to provide
power to the control circuit
Head Pressure Control by Ambient Fan Cycling
Condenser fans are controlled by ambient temperature using
electronic temperature controls . Ambient fan cycling is
recommended for multi-circuited condensers or single circuit
condensers where there is little variation in condenser load, such
as the condenser model # RC1-08A, which is a single row of
fans to serve one of the refrigeration circuits of a 30-ton module,
model AR2-30 .
Ambient fan cycling is limited in its ability to control head
pressure to mild ambient conditions, see Table 2 for minimum
recommended ambient temperatures for fan cycling . By request,
ClimaCool can provide year round head pressure control by
combining ambient fan cycling with other such methods as
flooded head pressure control, or variable speed fans . Combining
flooded controls with ambient fan cycling also provides the
advantage of reducing the refrigerant required to flood the
condenser . Refer to Table 3 for typical settings for ambient
thermostats .
Application Parameters
Head Pressure Control by Ambient Fan Cycling
The most common method for controlling head pressure is to
cycle the condenser fans using high pressure control switches
sensing condenser pressure . Again, the fans closest to the header
end of the unit run continuously, thus second fan in each row will
cycle independently to control head pressure corresponding to the
refrigerant circuit it serves . As with ambient fan cycling, it is also
possible to combine alternate methods of head pressure control
with fan cycling by head pressure . Contact the factory for more
precise regulation of head pressure as required .
2
1
Table 2 - Minimum Ambient for Fan Cycling.
Desi n T.D.*
Number of Fans
Single Row Double
Row 30
25
20
15
10
2
4
35
45
55
60
70
3
6
15
30
40
55
65
4
8
0
15
30
45
60
5
10
0
10
20
35
55
6
12
0
0
10
30
50
Table 3 - Ambient Fan Cycling Thermostat Settings
Design
Thermostat Settin
Number of Fans
Single Bow Double Row
T.D.
2
4
30
60
25
65
20
70
15
75
3
6
30
60
40
25
65
55
20
70
60
15
75
65