41
*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 sec-
ond stage cooling
b
y turning on the fan to high and opening the OA damper 100%
b
efore the first stage mechanical cooling is ena
b
led.
†With stage 3 delay (STG3 DLY) in Advanced setup menu can turn on second stage of mechanical cooling Y2–O after the delay if the call for Y1–I and
Y2–I have not
b
een satisfied.
ENTHALPY SETTINGS
When the OA temperature, enthalpy and dew point are below the
respective set points, the Outdoor Air can be used for economiz-
ing. Figure 55 shows the new single enthalpy boundaries in the
W7220. There are 5 boundaries (set points ES1 through ES5),
which are defined by dry bulb temperature, enthalpy and dew
point.
Refer to Table 15 for ENTH CURVE set point values.
The W7220 calculates the enthalpy and dew point using the OA
temperature and humidity input from the OA enthalpy sensor.
When the OA temperature, OA humidity and OA dew point are
all below the selected boundary, the economizer sets the econo-
mizing mode to YES, economizing is available.
When all of the OA conditions are above the selected boundary,
the conditions are not good to economize and the mode is set to
NO.
Figure 55 shows the 5 current boundaries. There is also a high lim-
it boundary for differential enthalpy. The high limit boundary is
ES1 when there are no stages of mechanical cooling energized and
HL (high limit) when a compressor stage is energized.
Table 14 — Enthalpy Operation With DCV (CO
2
Sensor) — 1 Speed Fan
DEMAND
CONTROLLED
VENTILATION (DCV)
OUTSIDE AIR
GOOD TO
ECONOMIZE
Y1-I
Y2-I
FAN
SPEED
Y1-O
Y2-O
OCCUPIED
UNOCCUPIED
Below CO
2
set
No
Off
Off
High
0-v/Off
0-v/Off
VENTMIN
Closed
On
Off
High
24-v/On
0-v/Off
VENTMIN
Closed
On
On
High
24-v/On
24-v/On
VENTMIN
Closed
Yes
Off
Off
High
0-v/Off
0-v/Off
VENTMIN
Closed
On
Off
High
0-v/Off
0-v/Off
VENTMIN to
Full-Open
Closed to
Full-Open
On
On
High
24-v/On
0-v/Off†
VENTMIN to
Full-Open
Closed to
Full-Open
Above CO
2
set
No
Off
Off
High
0-v/Off
0-v/Off
VENTMIN to
VENTMAX
Closed
On
Off
High
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
High
0-v/Off
0-v/Off
VENTMIN L to
VENTMAX
Closed
On
Off
High
0-v/Off
0-v/Off
VENTMIN to
Full-Open
Closed to
Full-Open
On
On
High
DELAY*
24-v/On
0-v/Off†
VENTMIN to
Full-Open
Closed to
Full-Open
Summary of Contents for WeatherMaster 50HCQ 04 Series
Page 4: ...4 Fig 2 50HCQ 04 06 Units Built On and After 4 15 2019 ...
Page 5: ...5 Fig 3 50HCQ 04 06 Units Built Prior to 4 15 2019 ...
Page 6: ...6 Fig 4 50HCQ 04 06 Corner Weights and Clearances ...
Page 7: ...7 Fig 5 50HCQ 04 06 Base Rail Details ...
Page 8: ...8 Fig 6 50HCQ 04 06 Thru the Base Charts ...
Page 23: ...23 Fig 41 Electro Mechanical Control Wiring 208 230v 460v ...
Page 24: ...24 Fig 42 Electro Mechanical Control Wiring 575v ...
Page 25: ...25 Fig 43 Electro Mechanical Power Wiring 208 230 1 60 ...
Page 26: ...26 Fig 44 Electro Mechanical Power Wiring 208 230 3 60 ...
Page 27: ...27 Fig 45 Electro Mechanical Power Wiring 460 3 60 ...
Page 28: ...28 Fig 46 Electro Mechanical Power Wiring 575 3 60 ...
Page 29: ...29 Fig 47 PremierLink Wiring Schematic 208 230 460v ...
Page 30: ...30 Fig 48 PremierLink Wiring Schematic 575v ...