D-EIMWC00804-14EN
Centrifugal Chillers
23
Oil Coolers
Daikin centrifugal chillers, sizes 063 through 126, have a factory-mounted, water-cooled oil
cooler, temperature-controlled water regulating valve and solenoid valve per compressor.
Model 050 chillers have refrigerant-cooled oil coolers and require no cooling water connection.
DWSC/DHSC single compressor cooling water connections are located near the compressor
and are shown on the specific unit certified drawings. Also see Figure 11 on page 25. Dual
compressor chillers, DWDC/ 063 - 126 and DWCC 100 - 126 are equipped as above, but the
water piping for the two oil coolers is factory-piped to a common inlet and outlet connection
located in the tube sheet under the evaporator. The exception to this is the DWDC 100 and 126
with 16-foot shells, where the common connections are centered at the rear of the unit. See
Figure 12 on page 25.
Field water piping to the inlet and outlet connections must be installed according to good piping
practices and include stop valves to isolate the cooler for servicing. A cleanable filter (40 mesh
maximum), and drain valve or plug must also be field-installed. The water supply for the oil
cooler should be from the chilled water circuit or from a clean, independent source, no warmer
than 80
°
F (27
°
C), such as city water. When using chilled water, it is important that the water
pressure drop across the evaporator is greater than the pressure drop across the oil cooler or
insufficient oil cooler flow will result. If the pressure drop across the evaporator is less than the
oil cooler, the oil cooler must be piped across the chilled water pump, provided that its pressure
drop is sufficient. The water flow through the oil cooler will be adjusted by the unit's regulating
valve so that the temperature of oil supplied to the compressor bearings (leaving the oil cooler)
is between 95
°
F and 105
°
F (35
°
C and 40
°
C).
Table 5, DWSC, Oil Cooler Data
Table 6, DWSC with Mounted VFD, Oil Cooler Data
NOTES:
1.
DWDC dual compressor units will have twice the cooling water flow rate of the comparable
DWSC
chiller and the pressure drop will be the same.
Cold Side Water
DWSC/DHSC 063 - 087
Flow, gpm
11.9
2.9
2.0
1.54
Inlet Temperature,
°
F
80.0
65.0
55.0
45.0
Outlet Temperature,
°
F
87.3
94.5
98.4
101.5
Pressure Drop, ft.
9.9
0.6
0.3
0.2
DWSC/DHSC 100 - 126
Flow, gpm
21.9
5.1
3.5
2.7
Inlet Temperature,
°
F
80.0
65.0
55.0
45.0
Outlet Temperature,
°
F
87.0
95.0
99.1
102.4
Pressure Drop, ft.
8.7
0.5
0.2
0.1
Cold Side Water
DWSC/DHSC 063 - 087
Flow, gpm
13.4
4.0
2.9
2.3
Inlet Temperature,
°
F
80.0
65.0
55.0
45.0
Outlet Temperature,
°
F
90.3
99.6
103.1
105.6
Pressure Drop, ft.
30.5
6.7
4.8
3.6
DWSC/DHSC 100 - 126
Flow, gpm
24.4
7.0
5.0
4.0
Inlet Temperature,
°
F
80.0
65.0
55.0
45.0
Outlet Temperature,
°
F
89.8
100.1
103.6
106.2
Pressure Drop, ft.
30.6
15.7
11.4
9.3
