Unit Startup and Maintenance
www.DaikinApplied.com 71
IOM 1274-3 • CENTRIFUGAL WATER CHILLERS
Table 33: Flow Volume Calculation
Figure 80: Upper Range of Minimum Flow
5. Once the SP is set, it is recommended that the sensor
be locked to avoid inadvertent readjustment. This can
be performed by pressing both the ‘+’ and ‘-’ buttons
simultaneously for 10 seconds. The indication goes out
momentarily indicating the unit is locked. To unlock, the
same procedure is performed to toggle to unlocked.
NOTE:
The LED window display on flow switch represents
a velocity range of 50 cm/s. The window centers on
the set point (SP). For example, if the SP was set to
200 cm/s, then the LED labeled ‘0’ would represent
a velocity of 180 cm/s when lit and the LED labeled 9
would represent a velocity of 230 cm/s when lit.
Each LED represents 5 cm/s, or two presses of the ‘+’
or ‘-’ buttons.
When power is initially applied to the flow switch, all
green LEDs light and go out step by step. During this
time, the output is closed. The unit is in the operating
mode.
When making manual adjustments to the set point
(SP), if no button is pressed for 2 seconds, the unit
returns to the operating mode with the newly set
value.
Flow below display range:
The SP LED will be lit red and
the leftmost LED will be flashing green. For example, if the SP
was set to 200 cm/s, the flashing labeled ‘0’ would indicate that
the flow was below 180 cm/s. This would be shown if no flow
through chiller or lowered than desired flow.
Figure 81: Display for Flow Below Range
Flow above display range:
The SP LED will be lit amber, all
LEDs to the left and right of the SP LED with be green with the
rightmost LED flashing green. For example, if the SP was set
to 200 cm/s, the flashing LED labeled ‘9’ would indicate that
the flow was above 230 cm/s. This may be a normal display
depending on range by which flow varies through chiller.
Figure 82: Display for Flow Above Range
Pipe Size
(inch)
Inside Pipe
Diameter
(inch)
US GPM at the velocities indicated below
GPM adjustment
per '+' or '-' key
input
Default
20 cm/sec
30 cm/sec
50 cm/sec
75 cm/sec 100 cm/sec 150 cm/sec 200 cm/sec 250 cm/sec 300 cm/sec
2
2.06
6.86
10.3
17.2
25.7
34.3
51.5
68.6
85.8
102.9
1.72
2.5
2.46
9.79
14.7
24.5
36.7
49.0
73.4
97.9
122.4
146.9
2.42
3
3.07
15.1
22.7
37.8
56.7
75.6
113.4
151.2
189.0
226.8
3.78
3.5
3.55
20.2
30.3
50.6
75.8
101.1
151.7
202.2
252.8
303.3
5.06
4
4.03
26.0
39.1
65.1
97.7
130.2
195.3
260.4
325.5
390.5
6.51
5
5.05
40.9
61.4
102.3
153.5
204.6
306.9
409.2
511.5
613.7
10.2
6
6.07
59.1
88.6
147.7
221.6
295.5
443.2
590.9
738.7
886.3
14.8
8
7.98
102.3
153.5
255.8
383.7
511.6
767.5
1023.3
1279.1
1534.7
25.6
10
10.02
161.3
241.9
403.2
604.8
806.5
1209.7
1612.9
2016.2
2419.1
39.0
12
11.94
229.0
343.4
572.4
858.6
1144.7
1717.1
2289.5
2861.9
3433.8
57.2
14
13.13
276.8
415.2
692.0
1037.9
1383.9
2075.9
2767.8
3459.8
4151.3
69.2
16
15.00
361.5
542.2
903.6
1355.5
1807.3
2710.9
3614.6
4518.2
5421.2
90.4
18
16.88
457.5
686.3
1143.8
1715.7
2287.6
3431.4
4575.2
5719.0
6862.1
114.4
20
18.81
572.4
853.0
1421.6
2132.4
2843.2
4264.8
5686.4
7108.0
8528.6
142.2
