Remote Temperature Sensor (Optional); Support Module Wiring (Optional); Equipment Control Module Wiring - Aprilaire 8840 Safety & Installation Instructions

INSTALLATION

REMOTE TEMPERATURE SENSOR (OPTIONAL)

A remote temperature sensor can be used for control if the thermostat is to be mounted in a concealed location
or a remote sensor can be averaged with the thermostat sensor to control a large space . An 8051 flush mount
or 8053 surface mount remote temperature sensor can be attached to the T1 and T2 terminals and mounted in a
recommended area . The remote sensor must be enabled in the installer setup menu, and once enabled will override
or be averaged with the thermostat's internal temperature sensor, based on the setting .
Remote temperature sensor should
be mounted:
• On an interior wall, in a frequently
occupied space .
• Approximately 5' above floor .
• At least 18" from outside wall .
• Using less than 300' of wire .
Do not mount remote sensor:
• Behind doors, in corners or other dead
air spaces .
• In direct sunlight, near lighting fixtures,
or other appliances that give off heat .
• On an outside or unconditioned area wall .
• In the flow of a supply register, in stairwells,
or near outside doors .
• On a wall with concealed pipes or ductwork .
• Near 120 VAC lines .

SUPPORT MODULE WIRING (OPTIONAL)

Up to 4 support modules can be wired for remote
sensing of temperature and/or humidity . Each sensor
can be configured for control or monitoring .
Note: Support modules should be wired with CAT-5
wire . The total length of wire for all support modules
should not exceed 1000 feet .
4
90-2124
MODEL 8081 OR 8082
SUPPORT MODULE
RSB RSA
RC C T1 T2 T3 T4
A
B 3
T2 2
T1 1
90-2169
INSTALLATION

EQUIPMENT CONTROL MODULE WIRING

Wire specifications:
18-24 gauge thermostat wire
Installation notes:
• Ensure power at the HVAC equipment is off .
• Loosen screw terminals, insert stripped wire
and re-tighten .
• Use zip tie to route wiring through the wiring
channels .
1 – Connection to terminal 1 at thermostat
2 – Connection to terminal 2 at thermostat
3 – Connection to terminal 3 at thermostat
RAT – Return air temperature sensor (optional)
LAT – Leaving air temperature sensor (optional)
ODT – Outdoor temperature sensor (included)
C – 24VAC common
R – 24VAC
RC – 24VAC cooling
RH – 24VAC heating
W – First stage heat (conventional)/auxiliary (heat pump)
W2 – Second stage heat (conventional)/ auxiliary (heat
pump)
W3/B – Third stage heat (conventional)/reversing valve
(heat pump)
Y – First stage cooling (conventional)/first stage compressor
(heat pump)
Y2 – Second stage cooling (conventional)/second stage
compressor (heat pump) .
Y3/0 – Third stage cooling (conventional)/reversing valve
(heat pump)
G – Fan
L – System fault indicator (heat pump only) (optional)
C – 24VAC common from heat pump for system fault
EQ
indicator (optional)
HUM – Humidifier
DHno & DHcom – Normally open dehumidifier control
DHnc & DHcom – Normally closed dehumidifier control
VENT – Ventilation
EAC – Electronic Air Cleaner
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