5464597-YIM-B-0518
Johnson Controls Ducted Systems
67
HPS2
(left pin)
24 VAC hot return from refrigerant circuit 2 High
Pressure Switch
Not effective for one stage compressor UCBs. Input is only
considered if C2 output is needed; input must be present to
allow C1 output. Three HPS2 trips in a two hour period cause a
“High Pressure Switch 1 Lockout” and C2 output is then
prevented until alarm reset. Connects through circuit trace to
the right LPS2 pin.
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.
Terminal SA BUS
1
connections on at left on lower edge and center of UCB
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
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
Item Integrated user interface at lower left corner of UCB
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
Table 30: Smart Equipment™ UCB Details (Continued)
Description
Function & Comments
