OM 1280-2 • MICROTECH UNIT CONTROLLER 20 www.DaikinApplied.com
Description of Operation
Cool Mode (Super State)
When in Cool mode the UVC uses primary cooling
(economizer) and secondary cooling (mechanical, hydronic)
as needed to maintain the effective DATS (see “Effective
Setpoint Calculations” on page 31). The keypad/display or
network connection can be used to force the unit into the Cool
mode. The Cool mode super state consists of the following
UVC states: CompCool#1, CompCool#2, EconComp#1,
EconComp#2, Water Cool, Air Econo Water, Air Econo,
Reheat, Reheat Low Limit, and Can’t Cool.
When the Cool mode super state becomes active, the UVC will
automatically determine which UVC state to make active based
upon the transitions for each state.
If the space temperature drops below EHS, and the
Emergency Heat function is enabled, the UVC will be forced
into the Emergency Heat mode (see “Emergency Heat Mode
(Super State)” on page 18).
Figure 12: Cool Mode Super State Diagram
Cool
Mode
Enter from:
LUI Input
Network Input
Auto Mode
Economizer
available?
Economizer
Mode
Compressor/Water
Mode
Yes
No
OADP=100%
for > 3 min
Economizer
Compressor/Water
Mode
Yes
Are inputs
valid?
Return to
previous state
Continually
Check Input
IAT, DAT, OAT
Econ avail.
Mech cool avail.
Are inputs
valid?
Can’t Cool
Mode
No
Continue in
current mode
Yes
Yes
No
DAT < VCLL
Reheat
Mode
HeatCap=100%
DAT < VCLL
Reheat Low Limit
Mode
OADP = OADH
DAT > VCLL
Yes
No
Yes
Yes
No
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