Daikin Magnitude WME092CD - Page 53

sTarTup and MaInTenanCe
www.DaikinApplied.com 53 IOM 1266-2 • MAGNITUDE
®
MODEL WME CHILLERS
If needed, the adapter is threaded into the pipe using pipe
sealant appropriate for the application. The ow sensor is
mounted onto the adapter using silicone grease. Carefully
apply lubricant to the inside threads and O-ring so temperature
probe does not become coated with lubricant. Torque the
adapter/sensor connection to 18.5 ft/lbs.
Wiring
Refer to wiring diagram in the unit control panel.
Either AC or DC is used to power the ow switch. The unit
controller’s digital input is a DC signal which is supplied
through the switch output of the ow switch for ow indication.
It is required that the AC and DC commons of power be
separated. Contact Chiller Technical Response for alternate
wiring scenarios.
Flow Switch Setup
The ow switch comes from the factory set at a default velocity
of 20 cm/s. This value is typically well below the minimum
water ow specied for the unit evaporator and condenser so
eld adjustment is required for adequate low ow protection.
Table 32 shows the calculated gallons per minute (gpm) for
Schedule 40 steel pipe for various uid velocities from
20 cm/s to 300 cm/s. The ow switch has an overall range of
adjustment from 3 cm/s to 300 cm/s.
Step 1: Adjust ow through the evaporator to the minimum
desired operating gpm. Maintain this ow throughout the setup
procedure.
Step 2: Once steady state minimum desired operating ow is
obtained, perform the ‘Teach’ function on the ow switch. The
‘Teach’ function is initiated by holding down the minus ‘-’ button
on the face of the ow switch for 15 seconds. During this 15
second period, LEDs ‘0’ and ‘9’ will be lit green. Once the
‘Teach’ function is completed, the outer LEDs will ash green
as shown in Figure 69.
Figure 69: Automatic Teach of Setpoint
Step 3: After the ‘Teach’ function is completed and the outer
LEDs have ashed, the ow switch will indicate a new setpoint
based upon the current ow which should still be at the steady
state minimum desired operating ow. Figure 70 shows a
typical display for this condition. All LEDs to the left of the
SP LED are lit green. The SP LED is lit RED (or may toggle
amber) which indicates that the ow switch is OPEN. Typically,
an increase in uid ow between 15% to 30% above the
‘Teach’ function ow is required for the SP LED to turn AMBER
and the ow switch to CLOSE indicating acceptable ow.
Figure 70: Teach Adjustment Complete
Table 32: Flow Volume Calculation
Pipe
Size
(inch)
Inside
Pipe
Diameter
(inch)
US GPM at the velocies 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 300cm/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