W8635A EQUIPMENT INTERFACE MODULE
3
69-1339—2
Fig. 5. Three zone configuration.
Fig. 6. Using wire nut to pigtail a connection when
three or more wires are terminated at one terminal.
Discovery Mode
Discovery mode begins when the T8635L Thermostat
and W8635 EIM are first installed and power is
connected:
— The W8635 EIM transmits information to the T8635L
Thermostat that indicates the maximum number of
stages that are enabled and the type of EIM
connected.
— The thermostat receives information from the W8635
and then sets the cycle rates and equipment types
automatically.
Stage Configuration
The W8635A automatically configures the T8635L for
two stages of heat and two stages of cool. If using the
W8635A and the T8635L on a one heat/one cool
application, set Installer Setup No. 5 and 8 to 1 when
configuring the T8635L Communicating Thermostat.
For configuration combinations, see Table 3.
Table 3. Stage Combinations.
Cycle Rate
The thermostat automatically sets the cycle rate based
on the information it received during Discovery Mode.
See Table 4.
To change the default cycle rate settings:
— enter T8635L Thermostat Installer Setup and select
the desired cycle rate settings for each stage. (All
stages can be set between 1 and 12 cph.)
Table 4. Default Cycle Rate Settings.
Electric Heat Setting
When using the W8635A on an electric heat application,
set the T8635L Thermostat Installer Setup No. 4 to 1.
This instructs the W8635A EIM to energize the fan with
any call for heat.
L1
(HOT)
L2
1
SYSTEM
TRANSFORMER
COOL 1
RELAY
HEAT 2
RELAY
FAN
RELAY
OT
OT
2
1
3
FACTORY INSTALLER JUMPERS.
M13430A
C7089B
OUTDOOR
TEMPERATURE
SENSOR
1
T8635L
HEAT 1
RELAY
W8635A
C
R
RH
RC
1
2
3
Y2
W2
Y1
G
W1
COOL 2
RELAY
W8703A
L1
(HOT)
L2
EXTERNAL
40 VA
TRANSFORMER
OT
OT
2
1
3
T8635L
OT
OT
2
1
3
T8635L
ZONE A
ZONE B
ZONE C
CLOSE
OPEN
OPEN
CLOSE
OPEN
CLOSE
COM
TR1
TR2
2
3
1
5
4
6
Z
2
1
3
X
5
4
6
Z
2
1
3
X
5
4
6
Z
2
1
3
X
TROL-A-TEMP
MODEL AOBD
ZONE DAMPER
OPTIONAL
TROL-A-TEMP
MODEL ARD-PC
OR MODEL ZD
WIRE NUT
M13378
Heat Stages
Cool Stages
1
0
2
0
0
1
0
2
1
1
2
2
W8635A
Equipment
Interface
Module
1
st
Stage
Heat
2
nd
Stage
Heat
1
st
Stage
Cool
2
nd
Stage
Cool
6 cph
6 cph
3 cph
3 cph