Power & Reset Options; Wiring Terminal - Aprilaire 8620W Safety & Installation Instructions

INSTAllATION
pOWER & RESET OpTIONS
The thermostat is powered from 24VAC . In the case of
power loss the thermostat will maintain the clock for 24
hours . The thermostat has a memory backup that saves
the thermostat settings in case of power interruption .
The reset button located under the cover on the front of
the thermostat can be used to reset the thermostat to
factory defaults . The system settings will also be set to
default .

WIRINg TERMINAl

I2 C I1 O/B Y Y2 G RC R W2 W L S2
I1 & I2 – Indoor Air Quality control output
C – Common
O/b – Reversing valve
Y – First stage cooling (conventional) / First stage compressor (heat pump)
Y2 – Second stage cooling (conventional) / Second stage compressor (heat pump)
g – Fan
RC – 24VAC supply cooling
1
R – 24VAC supply heating
1
W2 – Second stage heat (conventional) / Second stage auxiliary (heat pump)
W – First stage heat (conventional) / First stage auxiliary (heat pump)
l – System fault indicator (optional) (heat pump only)
S1 & S2 – outdoor temperature sensor (included)
T1 & T2 – remote temperature sensor (optional)
1 Jumper between RC & R is used in single transformer systems (see wiring diagrams).
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Wire specifications:
18-24 gauge thermostat wire
Installation notes:
S1 T1 T2
• Ensure power at the HVAC equipment is off.
• Loosen screw terminals, insert stripped wire
and re-tighten .
• Push the excess wire back into the opening
and plug the wall opening to prevent drafts .
INSTAllATION
CONVENTIONAl HEAT/COOl WIRINg DIAgRAMS
SINglE TRANSfORMER (USE JUMpER WIRE)
RESET
BUTTON
90-2012
I2 C I1 O/B Y Y2 G
HEAT pUMp WIRINg DIAgRAMS
SINglE TRANSfORMER (USE JUMpER WIRE)
I2 C I1 O/B Y Y2 G
TWO TRANSfORMERS (REMOVE JUMpER WIRE)
RC R W2 W L S2 S1 T1 T2 I2 C I1 O/B
TWO TRANSfORMERS (REMOVE JUMpER WIRE)
I2 C I1 O/B
RC R W2 W L S2 S1 T1 T2
Y Y2 G RC R W2 W L S2 S1 T1 T2
Y Y2 G RC R W2 W L S2 S1 T1 T2
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