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31-5000734 Rev. 0
On-Board Links
Carefully review all configuration information provided.
Failure to properly set DIP switches, jumpers and on-
board links can result in improper operation!
WARNING
On-Board Link W914 Dehum (R to DS)
On-board link W914, is a clippable connection between
terminals R and DS on the integrated control. W914 must
be cut when the furnace is installed with either the zone
control or a thermostat which features humidity control. If
the link is left intact the PMW signal from the zone control
will be blocked and also lead to control damage. Refer to
Table 11 for operation sequence in applications including
NF80XV, a thermostat which features humidity control and
a single-speed outdoor unit. Table 12 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
terminals 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
energized 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
terminals 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
cooling only.
Operating Sequence
System Demand
System Response
System Condition
Step
Thermostat Demand
Relative Humidity
Compressor
Blower
CFM
(cool)
Comments
Y1
O
G
W1
Status
D
NO CALL FOR DEHUMIDIFICATION
Normal Operation
1
On
On
On
Acceptable 24 VAC
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 VAC
High
100%
Thermostat energizes Y1 and de-
energizes D on a call for de-humidification
Dehumidification Call
2
On
On
On
Demand
0 VAC
High
70%*
PRECISION MODE (operates independent of a Y1 demand)
Normal Operation
1
On
On
On
Acceptable 24 VAC
High
100%
Dehumidification mode begins when
humidity is greater than set point
Dehumidification Call
2
On
On
On
Demand
0 VAC
High
70%*
Dehumidification Call
Only
1
On
On
On
Demand
0 VAC
High
70%*
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
*Dehumidification blower speed is 70% of COOL speed for all units.
**In Precision mode, thermostat will maintain room temperature up to 2 °F (1.2°C) cooler than room setting.
Table 11. Operating Sequence
NF80XV, Thermostat with Humidity Control Feature and Single-Speed Outdoor Unit
