1183875-YIM-A-1014
68
Johnson Controls Unitary Products
JOY
4-way Joystick for display menu navigation
Item USB connector at right of UCB
J10
Type A female Universal Serial Bus connector
Used for backup, restoration, & copying of board parameters as
well as board software updating through a flash drive
Optional communication sub-board at center of UCB
Terminal FC BUS connections on left edge of the communication board
FC+
FC (“Field Connected”) BUS BACnet MSTP
communication
Positive of the VDC (typically, a fluctuating 1.5 to 3.5 volts
reading to COM; at least 0.25
volts higher than
–
) FC bus BACnet MSTP communication
circuit
FC–
FC (“Field Connected”) BUS BACnet MSTP
communication
Positive of the VDC (typically, a fluctuating 1.5 to 3.5 volts
reading to COM; at least 0.25
volts lower than +) FC bus BACnet MSTP communication circuit
COM
Common for the FC (“Field Connected”) BUS
BACnet MSTP communication circuit
Negative of the VDC FC bus BACnet MSTP communication
circuit
SHLD
Shield for the FC (“Field Connected”) BUS
BACnet MSTP communication circuit
Earth ground reference of the cable to prevent interference on
the FC bus BACnet MSTP communication circuit
Item Selector in red housing at left on top edge of the communication board
EOL
switch
End Of Line selector switch for the FC BUS
BACnet MSTP communication circuit
ON selected only for the UCB that is the terminus of the FC bus
BACnet MSTP communication cable to prevent signal “bounce-
back”
LEDs on the communication board
EOL
Green End Of Line indicator
Lit indicates the EOL switch is selected ON
FC BUS
Green FC bus communication transmission
indicator
Lit/flickering indicates outgoing UCB FC bus communication is
currently active, off indicates the UCB is awaiting incoming FC
bus communication
ISO PWR
Green communication board Isolated Power
indicator
Lit indicates the UCB is supplying power to the communication
sub-board
Table 29: Simplicity SE UCB Details (Continued)
Description
Function & Comments
Table 30: Ignition Control Flash Codes
Flashes
Fault Conditions
Check
STEADY ON
Control Failure
Control
HEARTBEAT
Normal Operation
1
Not Applicable
2
Pressure Switch Stuck Closed
Pressure Switch
3
Pressure Switch Failed To Close
Venter Pressure Switch Vent Blocked
4
Limit Switch Open
Main Limit
AUX Limit
5
Flame Present With Gas Off First Stage Gas Valve
Energized With W1 Off Second Stage Gas Valve
Energized With First Stage Gas Valve Off
Gas Valve
6
Ignition Lockout
Gas Flow
Gas Pressure
Gas Valve
Flame Sensor
STEADY OFF
No Power Or Control Failure
24VAC or Control