Lennox International Inc SL280UH090V36B, SL280UH090V48B Table Operating Sequence, Page

TABLE 19

OPERATING SEQUENCE

SL280UHV, Non−Communicating Thermostat with Humidity Control Feature and Two−Speed Outdoor Unit

OPERATING

SYSTEM DEMAND

SYSTEM RESPONSE

SEQUENCE

Thermostat Demand

Relative Humidity

Blower

System

Ste

W

W

Compressor

CFM

Comments

Condition

p

Y1

Y2

O

G

Status

D

1

2

(COOL)

NO CALL FOR DEHUMIDIFICATION

Normal Opera-

1

On

On

On

Acceptable

24

Low

70%*

tion − Y1

VAC

Compressor and indoor

blower follow thermostat

Normal Opera-

24

2

On

On

On

On

Acceptable

High

100%

demand

tion − Y2

VAC

ROOM THERMOSTAT CALLS FOR FIRST STAGE COOLING

BASIC MODE (only active on a Y1 thermostat demand)

Normal Opera-

1

On

On

On

Acceptable

24

Low

70%*

ComfortSense® 7000

tion

VAC

thermostat energizes Y2

Dehumidification

2

On

On

On

On

Demand

0

High

70%**

and de−energizes D on a

Call

VAC

call for de−humidification

PRECISION MODE (operates independent of a Y1 thermostat demand)

Normal Opera-

1

On

On

On

Acceptable

24

Low

70%*

tion

VAC

Dehumidification mode

begins when humidity is

Dehumidification

0

2

On

On

On

On

Demand

High

70%**

greater than set point

call

VAC

ComfortSense® 7000

thermostat will try to

Dehumidification

0

maintain room humidity

1

On

On

On

On

Demand

High

70%**

setpoint by allowing the

call ONLY

VAC

room space to maintain a

cooler room thermostat

setpoint***

ROOM THERMOSTAT CALLS FOR FIRST AND SECOND STAGE COOLING

BASIC MODE (only active on a Y1 thermostat demand)

Normal Opera-

1

On

On

On

On

Acceptable

24

High

100%

ComfortSense® 7000

tion

VAC

thermostat energizes Y2

Dehumidification

2

On

On

On

On

Demand

0

High

70%**

and de−energizes D on a

call for de−humidification

Call

VAC

PRECISION MODE (operates independent of a Y1 thermostat demand)

Normal Opera-

1

On

On

On

Acceptable

24

Low

70%*

tion

VAC

Dehumidification mode

begins when humidity is

Dehumidification

0

2

On

On

On

On

Demand

High

70%**

greater than set point

call

VAC

Dehumidification

1

On

On

On

On

Demand

0

High

70%**

ComfortSense® 7000

call ONLY

VAC

thermostat will try to

maintain room humidity

Jumpers at indoor unit with a two stage outdoor unit

setpoint by allowing the

room space to maintain a

Cut factory jumper from Y1 to Y2 or cut W915 (Y1 to Y2)

cooler room thermostat

With Condensing unit − Cut W914 (R to DS) on SureLight® control

With Heat Pump − Cut W914 (R to DS) & W951 (R to O) on SureLight® control

setpoint***

Dave Lennox ComfortSense® 7000 thermostat to use for this application − Y2081 4 heat / 2 cool *Normal operation first stage cooling blower speed is 70% COOL speed.

**Dehumidification blower speed is, reduced to 70% of COOL.

***In Precision mode, ComfortSense® 7000 thermostat will maintain room temperature up to 2 °F (1.2°C) cooler than room setting.

Page 50