![Automated Logic RC642 Technical Instructions Download Page 55](http://html.mh-extra.com/html/automated-logic/rc642/rc642_technical-instructions_3021520055.webp)
51
N.C.
N.O.
M
M
AO - Mixed air dampers
(optional)
OA
DA
M
BO - Fan start/stop
AI - Discharge air temp
(optional)
HP
BO - Compressor stage 1
BO - Compressor stage 2
Elec
BO - Heating stage 1
(optional)
BO - Heating stage 2
(optional)
BO - Reversing valve
T
T
AI - Zone temp
AI - Zone setpoint adjust
BI - Zone override
T
T
BI - Freezestat
(optional)
AI - Outside air temp
(optional)
Hardware Points
Point Name
AI
BI
BO
AO
I/O #
Comments
Zone temp
X
Internal
Zone setpoint
adjust
X
Internal
Zone override
X
Internal
Outdoor air temp
X
UI-1
Optional – Requires sensor
(Type II thermistor)
NOTE
Short input to ground if
not used.
Discharge air temp X
UI-2
Optional – Requires sensor
(Type II thermistor)
Freezestat
X
UI-3
Optional – Requires sensor
(dry contact)
Compressor stage 1
X
DO-1 (Y1) Relay output
Compressor stage 2
X
DO-2 (Y2) Relay output
#3: Air source heat pump - reverse to cool
Control schematic
Point list