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Table 30: Smart Equipment™ UCB Details (Continued)
FAULT
SA BUS
ST
COM
SSO
SAT+
RAT+
OAT+
CC1+
EC1+
CC2+
EC2+
RAH+
DCT PRS+
DFS (upper pin)
Johnson Controls Ducted Systems
Description
Red hard lockout, networking error and firmware
error indicator
Green UCB SA bus communication transmission
indicator
Terminal Space temperature sensor connections at center on upper edge of UCB
Space Temperature sensor input from 10KΩ @
77°F, Type III negative temperature coefficient
thermistor
Common for ST and SSO inputs
Space Sensor Offset input from 0 to 20KΩ
potentiometer
Pin Temperature sensor connections at right on upper edge of UCB
Supply Air Temperature sensor input from 10KΩ
@ 77°F, Type III negative temperature coefficient
thermistor
Return Air Temperature sensor input from 10KΩ
@ 77°F, Type III negative temperature coefficient
thermistor
Outside Air Temperature sensor input from 10KΩ
@ 77°F, Type III negative temperature coefficient
thermistor
#1 refrigerant circuit Condenser Coil temperature
sensor input from 10KΩ @ 77°F, Type III negative
temperature coefficient thermistor
#1 refrigerant circuit Evaporator Coil temperature
sensor input from 10KΩ @ 77°F, Type III negative
temperature coefficient thermistor
#2 refrigerant circuit Condenser Coil temperature
sensor input from 10KΩ @ 77°F, Type III negative
temperature coefficient thermistor
#2 refrigerant circuit Evaporator Coil temperature
sensor input from 10KΩ @ 77°F, Type III negative
temperature coefficient thermistor
Pinned connections on right edge of UCB
Return Air Humidity input from 0-10 VDC @ 0-
100% RH sensor
Supply Duct Pressure input from 0-5 VDC @ 0-5"
w.c. sensor
24 VAC hot return from Dirty Filter Switch
Function & Comments
1/2 second on/off flashing indicates one or more alarm is
currently active, 1/10th second on/off flashing indicates a
networking error (polarity, addressing, etc.) or a firmware error
(likely correctable with re-loading from USB flash drive)
Lit/flickering indicates UCB SA bus communication is currently
active, off indicates the UCB is awaiting SA bus communication
Positive of VDC circuit (3.625 VDC reading to COM with open
circuit), effective if "Thermo- stat-only Control" parameter is set
OFF, space sensor override momentary shorts ST to COM to
initiate/terminate temporary occupancy
Negative of VDC circuit for ST and SSO inputs
Positive of VDC circuit (3.625 VDC reading to COM with open
circuit), 10KΩ/2.5 VDC is 0°F offset, 0Ω/0 VDC is maximum
above offset and 20KΩ/3.4 VDC is maximum below offset from
active space temperature setpoint
Input required for operation; 3.625 VDC reading SAT+ to SAT–
with open circuit. Used in heat/cool staging cutouts, free cooling
operation, demand ventilation operation, comfort ventilation
operation, economizer loading operation, VAV cooling
operation, hydronic heat operation.
Input required for operation; 3.625 VDC reading RAT+ to RAT–
with open circuit. Used in return air enthalpy calculation.
Substitutes for space temperature if no other space
temperature input is present.
Input required for operation but may be a communicated value;
3.625 VDC reading OAT+ to OAT– with open circuit. Used in
heat/cool cutouts, low ambient cooling determination, dry bulb
free cooling changeover, outside air enthalpy calculation,
economizer loading operation, heat pump demand defrost
calculation.
Input required for heat pump units, not required for A/C units;
3.625 VDC reading CC1+ to CC1– with open circuit. Used in
heat pump demand defrost calculation.
Input required for operation; 3.625 VDC reading EC1+ to EC1–
with open circuit. Used in suction line temperature safety.
Input required for 2-compressor heat pump units, not required
for 2-compressor A/C units, not active for 1-compressor units;
3.625 VDC reading CC2+ to CC2– with open circuit. Used in
heat pump demand defrost calculation.
Input required for operation of 2-compressor units, not active for
1-compressor units; 3.625 VDC reading EC2+ to EC2– with
open circuit. Used in suction line temperature safety.
Input required for reheat units, optional in all other units, may be
a communicated value. Used in return air enthalpy calculation,
temperature/humidity setpoint reset, reheat operation.
Input required for variable air volume units. Used in VAV indoor
blower operation.
Optional input; switch closure for greater than 15 seconds
during indoor blower operation initiates a notification alarm
5565606-TIM-B-1018
63
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