SOLID STATE ECONOMIZER SYSTEM
63-2484—1
13
Fig. 15. Partial psychrometric chart with single C7400A Solid State Enthalpy Sensor and
W7459 Solid State Economizer Logic Module performance curves.
CONTROL
CURVE
A
B
C
D
CONTROL POINT
APPROX. °F (°C)
AT 50% RH
73 (23)
70 (21)
67 (19)
63 (17)
12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42
44 46
90
100
80
70
60
50
40
30
2
0
10
ENTHALPY—BTU PER POUND DRY AIR
85
(29)
90
(32)
95
(35)
100
(38)
105
(41)
110
(43)
35
(2)
35
(2)
40
(4)
40
(4)
105
(41)
110
(43)
45
(7)
45
(7)
50
(10)
50
(10)
55
(13)
55
(13)
60
(16)
60
(16)
65
(18)
65
(18)
70
(21)
70
(21)
75
(24)
75
(24)
80
(27)
80
(27)
85
(29)
90
(32)
95
(35)
100
(38)
APPROXIMATE DRY BULB TEMPERATURE—°F (°C)
A
A
B
B
C
C
D
D
M11160
RELATIVE HUMIDITY (%)
1
1
HIGH LIMIT CURVE FOR W6210D,W7210D,W7459D.
20
10
30
40
50
60
70
80
90
100
605040 70 80 90 100
PERCENT RH
TEMPERATURE °F (°C)
M9101
C7400A OUTPUT CURRENT
4 mA
6 mA
8 mA
10 mA
20 mA
18 mA
16 mA
14 mA
12 m
A
(4) (10) (16) (21) (27) (32) (38)
40
45 50 55
60 65
70 75 80 85 90
95
100
19
18
17
16
15
14
13
12
11
10
9
LED OFF
LED OFF
LED OFF
LED OFF
LED ON
LED ON
LED ON
LED ON
D
C
B
A
mA
°F
NOTE: A,B,C,D ARE W7459 SWITCHING SETPOINTS.
M7578A
Fig. 16. C7400A Sensor output current vs.
relative humidity.
Fig. 17. C7650A Solid State Temperature Sensor output
current vs. temperature.