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43
Table 18 — Enthalpy Operation, No Demand Controlled Ventilation (DCV) (CO
2
Sensor) — 2 Speed Fan
*With 2SP FAN DELAY (Advanced Setup Menu) when in the
economizing mode there is a delay for the high speed fan to try to
satisfy the call for second stage cooling by turning on the fan to high
and opening the OA damper 100% before the first stage mechanical
cooling is enabled.
†
With stage 3 delay (STG3 DLY) in Advanced setup menu, second
stage of mechanical cooling Y2-O can be turned on after the delay if the
calls for Y1-I and Y2-I have not been satisfied.
Table 19 — Enthalpy Operation, with Demand Controlled Ventilation (DCV) (CO
2
Sensor) — 2 Speed Fan
*With 2SP FAN DELAY (Advanced Setup Menu) when in the
economizing mode there is a delay for the high speed fan to try to
satisfy the call for second stage cooling by turning on the fan to high
and opening the OA damper 100% before the first stage mechanical
cooling is enabled.
†
With stage 3 delay (STG3 DLY) in Advanced setup menu, second
stage of mechanical cooling Y2-O can be turned on after the delay if the
calls for Y1-I and Y2-I have not been satisfied.
Table 20 — Single Enthalpy and Dual Enthalpy High Limit Curves
Enthalpy Settings
When the OA temperature, enthalpy and dew point are below
the respective setpoints, the Outdoor Air can be used for econ-
omizing. Figure 50 shows the new single enthalpy boundaries
in the W7220. There are 5 boundaries (setpoints ES1 through
ES5), which are defined by dry bulb temperature, enthalpy and
dew point.
Refer to Table 20 for ENTH CURVE setpoint values.
The W7220 calculates the enthalpy and dew point using the
OA temperature and humidity input from the OA enthalpy sen-
sor. When the OA temperature, OA humidity and OA dew
point are all below the selected boundary, the economizer sets
the economizing mode to YES, economizing is available.
When all of the OA conditions are above the selected bound-
ary, the conditions are not good to economize and the mode is
set to NO.
Figure 50 shows the 5 current boundaries. There is also a high
limit boundary for differential enthalpy. The high limit bound-
ary is ES1 when there are no stages of mechanical cooling en-
ergized and HL (high limit) when a compressor stage is
energized.
DCV
OUTSIDE AIR
GOOD TO
ECONOMIZE?
Y1-I
Y2-I
FAN SPEED
Y1-O
Y2-O
OCCUPIED
UNOCCUPIED
None
No
Off
Off
Low
0-v/Off
0-v/Off
MIN POS L
Closed
On
Off
Low
24-v/On
0-v/Off
MIN POS L
Closed
On
On
High
24-v/On
24-v/On
MIN POS H
Closed
Yes
Off
Off
Low
0-v/Off
0-v/Off
MIN POS L
Closed
On
Off
Low
0-v/Off
0-v/Off
MIN POS L to Full-Open
Closed to Full-Open
On
On
High
DELAY*
24-v/On
0-v/Off
†
MIN POS H to Full-Open
Closed to Full-Open
DCV
OUTSIDE AIR
GOOD TO
ECONOMIZE?
Y1-I
Y2-I
FAN SPEED
Y1-O
Y2-O
OCCUPIED
UNOCCUPIED
Below Set
No
Off
Off
Low
0-v/Off
0-v/Off
VENTMIN L
Closed
On
Off
Low
24-v/On
0-v/Off
VENTMIN L
Closed
On
On
High
24-v/On
24-v/On
VENTMIN H
Closed
Yes
Off
Off
Low
0-v/Off
0-v/Off
VENTMIN L
Closed
On
Off
Low
0-v/Off
0-v/Off
VENTMIN L to Full-Open
Closed to Full-Open
On
On
High
24-v/On
0-v/Off
†
VENTMIN H to Full-Open
Closed to Full-Open
Above Set
No
Off
Off
Low
0-v/Off
0-v/Off
VENTMIN L to VENTMAX
Closed
On
Off
Low
24-v/On
0-v/Off
VENTMIN L to VENTMAX
Closed
On
On
High
24-v/On
24-v/On
VENTMIN H to VENTMAX
Closed
Yes
Off
Off
Low
0-v/Off
0-v/Off
VENTMIN L to VENTMAX
Closed
On
Off
Low
0-v/Off
0-v/Off
VENTMIN L to Full-Open
Closed to Full-Open
On
On
High
DELAY*
24-v/On
0-v/Off
†
VENTMIN H to Full-Open
Closed to Full-Open
ENTHALPY
CURVE
TEMP. DRY
BULB (F)
TEMP.
DEWPOINT (F)
ENTHALPY
(btu/lb/da)
POINT P1
POINT P2
TEMP. (F)
HUMIDITY
(%RH)
TEMP. (F)
HUMIDITY
(%RH)
ES1
80
60
28.0
80
36.8
66.3
80.1
ES2
75
57
26.0
75
39.6
63.3
80.0
ES3
70
54
24.0
70
42.3
59.7
81.4
ES4
65
51
22.0
65
44.8
55.7
84.2
ES5
60
48
20.0
60
46.9
51.3
88.5
HL
86
66
32.4
86
38.9
72.4
80.3
Summary of Contents for 50HCQD07
Page 4: ...4 Fig 2 Unit Dimensional Drawing 07 08 Size Units ...
Page 5: ...5 Fig 2 Unit Dimensional Drawing 07 08 Size Units cont ...
Page 6: ...6 Fig 3 Unit Dimensional Drawing 09 Size Units ...
Page 7: ...7 Fig 3 Unit Dimensional Drawing 09 Size Units cont ...
Page 24: ...24 Fig 37 Electro Mechanical Control Wiring 50HCQ A07 D07 208 230v 460v 575v ...
Page 25: ...25 Fig 38 Electro Mechanical Control Wiring 50HCQ D07 Tier 2 1 Compressor 208 230v 460v 575v ...
Page 26: ...26 Fig 39 Electro Mechanical Control Wiring 50HCQ 08 09 208 230v 460v 575v ...
Page 27: ...27 Fig 40 Electro Mechanical Power Wiring 50HCQ A07 D07 208 230v 460v 575v ...
Page 28: ...28 Fig 41 Electro Mechanical Power Wiring 50HCQ D07 Tier 2 1 Compressor 208 230v 460v 575v ...
Page 29: ...29 Fig 42 Electro Mechanical Power Wiring 50HCQ 08 09 208 230v 460v 575v ...
Page 30: ...30 Fig 43 PremierLink Wiring Schematic 50HCQ07 09 208 230v 460v 575v ...
Page 31: ...31 Fig 44 RTU Open System Control Wiring ...
Page 49: ......