507746-01
Issue 1821
Page 28 of 39
Table 15. BCE7S with Non-Communicating Thermostat and Two-Stage Outdoor Unit
Operating Sequence
Operating Sequence
System Demand
System Response
System
Condition
Step
Thermostat Demand
Relative Humidity
Comp
Air
Handler
CFM
(COOL)
Comments
Y1
Y2
O
G
W1
W2
Status
D
NO CALL FOR DEHUMIDIFICATION
Normal Operation
- Y1
1
On
On
On
Acceptable 24 VAC
Low
70%
Compressor and indoor air handler
follow thermostat demand.
Normal Operation
- Y2
2
On
On
On
On
Acceptable 24 VAC
High
100%
Room Thermostat Calls for First-Stage Cooling
BASIC MODE (only active on a Y1 thermostat demand)
Normal Operation
1
On
On
On
Acceptable 24 VAC
Low
70%
Thermostat energizes Y2 and de-
energizes D on a dehumidification
demand. NOTE - No over cooling.
Dehumidification
demand
2
On
On
On
On
Demand
0 VAC
High
100%
PRECISION MODE (operates independent of a Y1 thermostat demand)
Normal Operation
1
On
On
On
Acceptable 24 VAC
Low
70%
Dehumidification mode begins when
humidity is greater than setpoint.
Dehumidification
demand
2
On
On
On
On
Demand
0 VAC
High
70%
Dehumidification
demand ONLY
1
On
On
On
On
Demand
0 VAC
High
70%
Thermostat will keep outdoor unit
energized after cooling temperature
has been reached in order to
maintain room humidity setpoint.
NOTE - Allow to cool 2°F beyond
cooling setpoint.
Room Thermostat Calls for First- and Second-Stage Cooling
BASIC MODE (only active on a Y1 thermostat demand)
Normal Operation
1
On
On
On
On
Acceptable 24 VAC
High
100%
Thermostat energizes Y2 and de-
energizes D on a dehumidification
demand. NOTE - No over cooling.
Dehumidification
demand
2
On
On
On
On
Demand
0 VAC
High
70%
PRECISION MODE (operates independent of a Y1 thermostat demand)
Normal Operation
1
On
On
On
On
Acceptable 24 VAC
High
100%
Dehumidification mode begins when
humidity is greater than setpoint.
Dehumidification
demand
2
On
On
On
On
Demand
0 VAC
High
70%
Dehumidification
demand ONLY
1
On
On
On
On
Demand
0 VAC
High
70%
Thermostat will keep outdoor unit
energized after cooling temperature
has been reached in order to
maintain room humidity setpoint.
NOTE - Allow to cool 2°F beyond
cooling setpoint.
