Table of Contents
Advertisement
2
1
Type Of Unit
Number of
Cooling S tages
Figure 5. Configuration DIP Switches
• Electric Heat / Electric Cool Units - Standard electric
heat / electric cool unit.
• Heat Pump Type 1 Units - Heat pump units which
internally energize the reversing valve. Lennox
commercial heat pumps operate in this manner.
• Heat Pump Type 2 Units - Heat pumps units which
require a thermostat signal to energize the reversing
valve. Most residential heat pumps operate in this
manner. Connect Lennox residential heat pumps to O"
output.
• Electric Cool / Gas Heat Units - Standard electric cool
/ gas heat unit.
• Air Handling Only Units - Switches 1 and 2 may be
set in any position for air handling units, but switches 3
through 6 must be set to OFF.
N
O
C
S
umber
f
OOliNg
tageS
Set switches 3 and 4 to identify the number of cooling
stages. See the following table and "Figure 5. Configuration
DIP Switches".
Table 4. Cooling Stages Switches
Switch 3
Switch 4
Number of Cooling Stages
OFF
OFF
None
ON
OFF
1 Stage
OFF
ON
2 Stages
ON
ON
3 Stages
N
O
h
S
umber
f
eatiNg
tageS
Set switches 5 and 6 to identify the number of heating
stages. See the following table and "Figure 5. Configuration
DIP Switches".
Table 5. Heating Stages Switches
Switch 3
Switch 4
Number of Heating Stages
OFF
OFF
None
ON
OFF
1 Stage
OFF
ON
2 Stages
6 7 8
3 4 5
Should be
OFF
Number of
Heating S tages
− S
3
witCheS
aNd
− S
5
witCheS
aNd
Local or Remote System Mode
l
s
oCal
ensoR
NTC ECTO A4.07 is factory−set to option 0 (local). In this
system mode, the NTC will operate the unit based on input
from a local sensor. A two−wire, thermistor− type sensor is
wired to NTC P178 terminals 1 and 2.r
R
s
emoTe
If an L Connection communication−ready sensor, such as
the Comfort Sensor, is specified, ECTO A4.07 must be set
to option 1 (remote). In this system mode, the NTC will
operate the unit based on input from the Comfort Sensor.
Connect the Comfort Sensor to the L Connection SysBus.
4
NOTE: The Comfort Sensor−Zoning is also an L Connection
communication−ready sensor but is designed for
use in L Connection zoning applications.
6
S
b
eNSOr
Optional return air sensor RT16 is used as a back−up if
the A2 or A74 sensor fails or is disconnected. If RT16 fails
or is not installed, unit heating and cooling operation stops.
NOTE: The RT16 has a lower resolution than the A2 local
sensor or the A74 remote sensor and should only
be used as back−up.
Page 4
NTC
SysBus
NCP
Local Sensor
(A2)
Figure 6. Local Sensor
ensoR
NTC
SysBus
SysBus
NCP
Figure 7. Remote Sensor
−u
O
aCk
p
peratiON
Comfort Sensor
(A74)
Advertisement
Table of Contents
