5566020-JIM-C-1019
Johnson Controls Ducted Systems
69
J
LPS2
(right pin)
24 VAC hot out for refrigerant circuit 2 Low
Pressure Switch
Not effective for one stage compressor UCBs. Connects through
circuit trace to the left HSP2 pin
LPS2
(left pin)
24 VAC hot return from refrigerant circuit 2 Low
Pressure Switch
Not effective for one stage compressor UCBs. Input is only
considered after 30 seconds of C2 output; afterwards, input must be
present to allow C2 output. Three LPS2 trips in a one hour period
cause a “Low Pressure Switch 2 Lockout” and C2 output is then
prevented until alarm reset.
FAN OVR
(right pin)
24 VAC hot out for indoor blower FAN Overload
relay contact/motor protector switch
Connects through circuit trace to the R terminal
FAN OVR
(left pin)
24 VAC hot return from indoor blower FAN
Overload relay contact/motor protector switch
Input is only considered if FAN output is needed; input must be
present to allow FAN output and unit operation. One FAN OVR trip
lasting longer than 5 minutes or three FAN OVR trips in a two hour
period cause a “Fan Overload Lockout” and unit operation is then
prevented until alarm reset.
Smart Equipment™ UCB - refrigerant circuit safety switch and indoor blower overload connections (continued)
Location
Label
Description
Function and comments
Smart Equipment™ UCB - SA BUS
1
connections
Location
Label
Description
Function and comments
K
PWR
Power for SA (“Sensor-Actuator”) BUS devices
Also incorporated in the J8 6-pin phone jack connector at the left-center of
the board. Positive of the 15 VDC (reading to C) circuit for powering an
optional netstat and/or Multi Touch gateway
C
Common for SA BUS power and communication
circuits
Also incorporated in the J8 6-pin phone jack connector at the left-center of
the board. Negative of the SA BUS circuits
–
Communication for SA BUS devices
Also incorporated in the J8 6-pin phone jack connector at the left-center of
the board. Positive of the VDC (typically, a fluctuating 1.5 to 3.5 volts
reading to C; at least 0.25 volts lower than +) SA BUS communication
circuit to optional economizer board, 4-stage board, fault detection &
diagnostics board, netstat and/or Multi Touch gateway
+
Communication for SA BUS devices
Also incorporated in the J8 6-pin phone jack connector at the left-center of
the board. Positive of the VDC (typically, a fluctuating 1.5 to 3.5 volts
reading to C; at least 0.25 volts higher than
–
) SA BUS communication
circuit to optional economizer board, 4-stage board, fault detection &
diagnostics board, netstat and/or Multi Touch gateway
L
J8
6-pin phone jack connector
Incorporates the SA BUS terminals for convenience/alternate connection
of SA BUS devices, primarily used for temporary service connection of the
Multi Touch gateway
1. When wiring unit and other devices using the SA Bus and FC Bus, see Table 32.
Smart Equipment™ UCB - user interface
Location
Label
Description
Function and comments
M
Display
On-board, 2-line x 8-character back-lit display
On-board display, buttons and joystick allow access to UCB,
economizer, 4-stage and FDD board parameters
ENTER
Button for display menu acknowledgment and navigation
CANCEL
Button for display menu navigation and zeroing of active
compressor ASCD timer
JOY
4-way Joystick for display menu navigation
