Lennox EL296UHV - Page 55

Page 55
On-Board Links
Note: In icomfortt systems with a conventional outdoor
unit (non-communicating), the on-board clippable links
must be set to properly configure the system.
WARNING
Carefully review all configuration information pro
vided. Failure to properly set DIP switches, jumpers
and on-board links can result in improper operation!
On-Board Link W914 Dehum or Harmony (R to DS)
On-board link W914, is a clippable connection between ter
minals R and DS on the integrated control. W914 must be
cut when the furnace is installed with either the Harmony
III zone control or a thermostat which features humidity
control. If the link is left intact the PMW signal from the Har
mony III control will be blocked and also lead to control
damage. Refer to table 18 for operation sequence in ap
plications including EL296UHV, a thermostat which fea
tures humidity control and a single-speed outdoor unit.
Table 19 gives the operation sequence in applications with
a two-speed outdoor unit.
On-Board Link W951 Heat Pump (R to O)
On-board link W951 is a clippable connection between ter
minals R and O on the integrated control. W951 must be cut
when the furnace is installed in applications which include a
heat pump unit and a thermostat which features dual fuel
use. If the link is left intact, terminal “O” will remain ener
gized eliminating the HEAT MODE in the heat pump.
On-Board Link W915 2 Stage Compr (Y1 to Y2)
On-board link W915 is a clippable connection between ter
minals Y1 and Y2 on the integrated control. W915 must be
cut if two-stage cooling will be used. If the Y1 to Y2 link is
not cut the outdoor unit will operate in second-stage cool
ing only.
TABLE 18
OPERATING SEQUENCE
EL296UHV, Non-Communicating Thermostat with Humidity Control Feature and Single-Speed Outdoor Unit
OPERATING
SEQUENCE
SYSTEM DEMAND SYSTEM RESPONSE
System
Condition
Step
Thermostat Demand Relative Humidity
Compres
sor
Blower
CFM
(COOL)
Comments
Y1 O G
W
1
Status D
NO CALL FOR DEHUMIDIFICATION
Normal Operation 1 On On On Acceptable
24
VA
C
High 100%
Compressor and indoor
blower follow thermostat
demand
BASIC MODE (only active on a Y1 thermostat demand)
Normal Operation 1 On On On Acceptable
24
VA
C
High 100%
ComfortSense
®
7000
thermostat energizes Y1
and de-energizes D on a
call for de-humidification
Dehumidification
Call
2 On On On Demand
0
VA
C
High 70%*
PRECISION MODE (operates independent of a Y1 thermostat demand)
Normal Operation 1 On On On Acceptable
24
VA
C
High 100%
Dehumidification mode
begins when humidity is
greater than set point
Dehumidification
call
2 On On On Demand
0
VA
C
High 70%*
Dehumidification
call ONLY
1 On On On Demand
0
VA
C
High 70%*
ComfortSense
®
7000
thermostat
will try to
maintain room humidity
setpoint by allowing the
room space to maintain a
cooler room thermostat
setpoint**
Jumpers at indoor unit with a single stage outdoor unit
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
Dave Lennox ComfortSense
®
7000 thermostat to use for this application - Y2081 4 heat / 2 cool
*Dehumidification blower speed is 70% of COOL speed for all units .
**In Precision mode, ComfortSense
®
7000 thermostat will maintain room temperature up to 2 °F (1.2°C) cooler than room setting.