Lennox LCH036 Installation Instructions Manual page 183

RT6
DISCHARGE
AIR SENSOR
Free Free
Cooling Cooling
Mode Setpoint
TEMP OFFSET
TEMP OAT STPT
Remote Remote
ENTH DIFF OFFSET (Two) C7400
ENTH ODE STPT
GLOBAL GLOBAL
*
Enthalpy includes effects of both temperature and humidity.
**Energy management system smay require additional field-provided sensors; refer to manufacturer's instructions.
FREE COOLING SETPOINT
Setpoint
Climate Zone
(Single Sensible)
75_F
1, 3, 5, 11-16
73_F
2, 4, 10
71_F
6, 8, 9
69_F
7
B-Setting Free Cooling Setpoint in Enthalpy Mode
507232-02 9/2015
ECONOMIZER MODES AND SETPOINT
Field-
Dampers will modulate to 55
Provided
Sensors
Outdoor air temperature (RT17) is less than return air temperature (RT16) by at
None Needed
least the OFFSET value.
None Needed Outdoor air temperature (RT17) is less than the OAT STPT value.
Either of the TEMP modes can be used when a network OAS signal is provided by
Energy
an energy management or building control system, via BACnet, LonTalk, or L Con­
Management
nection. The network can command OAS, NOT OAS, or AUTO. AUTO returns to
System**
local control of OAS, which is the selected TEMP mode.
Outdoor air enthalpy* (A7) is less than return air enthalpy (A62) by at least the OFF­
SET value.
C7400 Outdoor air enthalpy (A7) is less than free cooling setpoint.
Global input is energized by (P297-9). This setting is also used for outdoor air damp­
24VAC Input
er applications. Global input also brings on the blower. (This mode is NOT used
Signal
when OAS signal is provided via network connection. GLO is only used when a
24VAC signal is used to energize the P297-9 GLO input.)
TABLE 21
Setpoint
(Differential Sensible)
0_F
2_F
4_F
6_F
RT6 SENSOR
FIGURE 38
TABLE 20
°
F discharge air (RT6) when outdoor
air is suitable:
Free Cooling Setpoint - ODE STPT
The enthalpy sensor (A7) provides a milliamp signal to the
Unit Controller based on outdoor air temperature and
humidity. See table 22. To set a free cooling setpoint of 73°F
at 50% relative humidity, enter "12" at the ODE STPT menu
prompt. The Unit Controller will allow dampers to modulate
Page 39
Permitted
Inputs
°
0-40 F
°
41-75 F
NA
0mA-4mA
12-19mA
NA