OM 750
Page 15 of 32
Econ State (state number 3)
The Econ state is a “normal” state that the UVC can go into when Cool
mode is active. The Econ state is typically active in the Cool mode
when primary cooling (economizer) is available and adequate to meet
the cooling requirements.
Transition
(Econ = Available
AND
Mech Cooling
≠
Available)
into State
OR
(Space
≠
High CO
2
AND
Heat PI = Saturated Low
AND
DAT > VCLL)
OR
((Mech PI = Saturated Low
AND
Econ Mech Timer =
Expired)
OR
(Mech Cooling
≠
Available))
Operation
When the Econ state becomes active, the UVC will
within State
use economizer cooling (see Economizer Operation)
as needed to maintain the effective cooling setpoint
(see Space Temperature Setpoints). The Econ Timer
(3-minutes fixed) will begin counting. The UVC will
monitor the DAT to ensure it does not fall below VCLL
(see Ventilation Cooling Low Limit) setpoint. The
CO
2
demand controlled ventilation function will be
active, if the unit is equipped for CO
2
control (see CO
2
Demand Controlled Ventilation), and the OA damper
will be adjusted as needed to maintain the CO
2
setpoint.
The UVC will remain in this state until one of the
transition out conditions become true, or until one of
the super state transition out conditions becomes true.
Transition
(Econ
≠
Available
AND
Mech Cooling
≠
Available)
out of State
OR
(Space = High CO
2
OR
DAT < VCLL)
OR
(Econ Timer = Expired
AND
Econ PI = Saturated High
AND
MechCool = Available)
OR
(Econ
≠
Available
AND
Mech Cooling = Available)
Figure 14. Econ State Operation (Occupied Mode and Auto Fan)
Figure 15. Econ Mech State Operation (Occupied Mode
and Auto Fan)
Econ Mech State (state number 1)
The Econ Mech state is a “normal” state that the UVC can go into when
Cool mode is active. The Econ Mech state is typically active in the Cool
mode when primary cooling (economizer) alone is not adequate to
meet the cooling requirements and both primary cooling and secondary
cooling (compressor) are available.
Transition
(Econ Timer = Expired
AND
Econ PI = Saturated
into State
High
AND
Mech Cooling = Available)
OR
(Econ = Available)
Operation
When the Econ Mech state becomes active, the OA
within State
damper will be set to 100% open, and the UVC will use
the unit’s mechanical cooling capabilities (see
Compressor Operation) as needed to maintain the
effective cooling setpoint (see Space Temperature
Setpoints). The Econ Mech Timer (3-minutes fixed)
will begin counting. The UVC will monitor the DAT
to ensure it does not fall below MCLL (see Mechanical
Cooling Low Limit) setpoint.
The UVC will remain in this state until one of the
transition out conditions become true, or until one of
the super state transition out conditions becomes true.
Transition
((Mech PI = Saturated Low
AND
Econ Mech Timer =
out of State
Expired)
OR
(Mech Cooling
≠
Available))
OR
(Econ
≠
Available)