Mode Selection - Aprilaire 8120 Safety & Installation Instructions

WIRING
If selecting a mode with temperature limits
(B, C or D), the outdoor temperature sensor must
be installed .
SElECT MOUNTING lOCATION fOR
OUTDOOR TEMPERATURE SENSOR (ODT)
The temperature sensor can be located in the
fresh air duct, in the vent inlet, or on the outside
of an exterior wall .
• Do not mount in direct sunlight.
• Do not mount closer than three feet to any
exhaust vent .
• Do not route wire alongside 120VAC wires.
• Do not use more than 300 feet of wire to
connect the sensor .
• Do not mount below the expected snow line
on exterior walls .
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fIGURE 7 – ODT Mounted Outside
nORTH, EAST OUTDOOR
OR WEST SIDE TEMpERATURE
OF HOME SEnSOR
SEnSOR
BRACkET
OUTDOOR
ABOVE EXpECTED
TEMpERATURE
SnOW LInE
SEnSOR LEADS
fIGURE 8 – ODT Mounted in Intake Duct
36" MAX.
OUTSIDE WALL

MODE SElECTION

This controller is equipped with 4 mode settings . The "A" mode allows the controller ventilate based on time only .
The "B", C", and "D" modes allow the controller to ventilate based upon time, outdoor temp, and indoor humidity .
Position Description
A
Timer controlled
ventilation (no
(Time Only)
temperature or
SEnSOR
humidity limits)
b
Timer controlled
ventilation with
(Default)
humidity and
temperature limits
CEnTER LInE
Chart
This setting can be calculated with ASHRAE 62 .2-2010 standards .
(Temperature and humidity sensors are ignored .)
100°
VENTILATION ALLOWED
50°
20°
VENTILATION ALLOWED WITH HEAT
0°
VENTILATION PREVENTED
15% 25% 35% 45%
INDOOR RELATIVE HUMIDITY
VENTILATION
PREVENTED
55% 65%
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