Carrier COBRA 48/50HJ004-014 User Manual
Page 37
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Table 2 — Light Commercial Thermidistat (LCT) Operating Sequence and System Response
LEGEND
*Unless unit compressor has been rewired as described in Step 11 (page 29).
UNOCCUPIED
COOLING
ER Comp
ER Fans
RT Comp 1
RT Comp 2
RT Fans
RT Heat
Indoor Temperature Above 2nd Stage
Set Point
Humidity Low & OAT Low
On
On (cyc.)
On w/o MM
Off
On (cyc.)
Off
Humidity Low & OAT High
Off
Off
On w/o MM
w/o MM
On (cyc.)
Off
Humidity High & OAT Low
Off
Off
On w MM
On w MM
On (cyc.)
Off
Humidity High & OAT High
Off
Off
On w MM
On w MM
On (cyc.)
Off
Indoor Temperature Between 1st and
2nd Stage Set Points
Humidity Low & OAT Low
Off
On (cyc.)
Off
Off
On (cyc.)
Off
Humidity Low & OAT High
Off
Off
On w/o MM
Off
On (cyc.)
Off
Humidity High & OAT Low
Off
Off
On w MM
Off
On (cyc.)
Off
Humidity High & OAT High
Off
Off
On w MM
Off
On (cyc.)
Off
Indoor Temperature Below 1st Stage
Set Point
Off
Off
Off
Off
Off
Off
NOTE: OAT < 55° all compression off*
HEATING
ER Comp.
ER Fans
RT Comps.
RT Fans
RT Heat
Indoor Temperature Above 1st Set
Point
Off
Off
Off
Off
Off
Indoor Temperature Between 1st and
2nd Stage Set Points
Off
Off
Off
On (cyc.)
On, 50%
Indoor Temperature Below 2nd Stage
Set Point
Off
Off
Off
On (cyc.)
On, 100%
OCCUPIED
COOLING
ER Comp
ER Fans
RT Comp 1
RT Comp 2
RT Fan
RT Heat
Indoor Temperature Above 2nd Stage
Set Point
Humidity Low & OAT Low
On
On
On w/o MM
On w/o MM
On
Off
Humidity Low & OAT High
On
On
On w/o MM
On w/o MM
On
Off
Humidity High & OAT Low
On
On
On w MM
On w MM
On
Off
Humidity High & OAT High
On
On
On w MM
On w MM
On
Off
Indoor Temperature Between 1st and
2nd Stage Set Points
Humidity Low & OAT Low
Off
On
Off
Off
On
Off
Humidity Low & OAT High
On
On
On w/o MM
Off
On
Off
Humidity High & OAT Low
On
On
On w MM
Off
On
Off
Humidity High & OAT High
On
On
On w MM
Off
On
Off
Indoor Temperature Below 1st Stage
Set Point
Humidity Low
Off
On
Off
Off
On
Off
Humidity High
On
On
Off
Off
On
Off
NOTE: OAT < 55° all compression off*
HEATING
ER Comp
ER Fans
RT Comps
RT Fans
RT Heat
Indoor Temperature Above 1st Stage
Set Point
Off
On
Off
On
Off
Indoor Temperature Between 1st and
2nd Stage Set Points
OAT >Set Pt
On
On
Off
On
Off
OAT
On
On
Off
On
On, 50%
Indoor Temperature Below 2nd Stage
Set Point
OAT >Set Pt
On
On
Off
On
On, 50%
OAT
On
On
Off
On
On, 100%
Comp — Compressor
ER
— Energy Recovery section
MM
— MoistureMi$er™ Dehumidification Device
OAT
— Outdoor-Air Temperature
RT
— Rooftop Unit
Set Pt — Set Point