Johnson Controls ZL Series Installation Manual page 57

Table 37: Smart Equipment™ ucb details (continued)
Limit, 24 VAC power and shutdown connections from unit wiring harness at left on upper edge of UCB
LIMIT
C
24 V
SD 24
SD R
R
W1
W2
Y1
Y2
G
OCC
X
R
SD-24
C
POWER
FAULT
SA BUS
ST
COM
SSO
SAT+
RAT+
OAT+
Description
Terminal Directional orientation: viewed with silkscreen labels upright
Monitored 24 VAC input through heat section limit switch(es)
24 VAC, 75 VA transformer Common
referenced to cabinet ground
24 VAC, 75 VA transformer hot
24 VAC hot out for factory accessory smoke
detector, condensate overflow and/or
user shutdown relay switching in series
24 VAC hot return from factory accessory
smoke detector, condensate overflow and
user shutdown relay switching in series
24 VAC hot for switched inputs to the UCB
Terminal Thermostat connection strip on left edge of UCB
1st stage heating request, 24 VAC input switched from R
2nd stage heating request, 24 VAC input switched from R
1st stage cooling request, 24 VAC input switched from R
2nd stage cooling request, 24 VAC input switched from R
Continuous indoor blower request,
24 VAC input switched from R
Occupancy request, 24 VAC input switched from R
Hard lockout indicator, 24 V output to a light thermostat LED
24 VAC hot for thermostat switching and power
If field-added external accessories for unit shutdown are
used, 24 VAC hot out for smoke detector, condensate
over- flow and/or user shutdown relay switching in series
24 VAC common for thermostat power
LEDs on left edge of UCB
Green UCB power indicator
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
Johnson Controls Ducted Systems
If voltage is absent, indicating the heat section is over-
temperature, the UCB will bring on the indoor blower
Connects through circuit traces to thermostat
connection strip C and indoor blower VFD pin C
Powers the UCB microprocessor, connects
through circuit trace to the SD 24 terminal
Connects through circuit trace to thermostat connection strip SD-24. A
wiring harness jumper plug connecting SD 24 to SD R is in place if factory
accessories for unit shutdown are not used - this jumper plug must be
removed if the switching of field-added external accessories for unit
shutdown are wired between thermostat connection strip SD-24 and R
Connects through circuit trace to the R terminal on the upper left of the board
Connects through circuit trace to the thermostat
connection strip R terminal, right FAN OVR pin, right
HPS1 pin, right HPS2 pin, lower DFS pin and lower APS pin
Not effective for cooling-only units
Not effective for cooling-only units or units with single-stage heat sections
Visible in the display menu when the #ClgStgs parameter is set
for 2 or more, also effective for economizer free cooling supply air
temperature reset when the #ClgStgs parameter is set for 1 or more
Must have the OccMode parameter set for External to be effective
If field-added external accessories for unit shutdown are
used, 24 VAC hot return from smoke detector, condensate
overflow and/or user shutdown relay switching in series
Unit wiring harness jumper plug for factory shutdown accessories must
be removed if the switching of field-added external accessories for unit
shutdown are wired between thermo- stat connection strip SD-24 and R
Lit indicates 24 VAC is present at C and 24 V terminals
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.
Installation Manual ZL Series 7.5- 12.5 Ton 60 Hertz R-410A
Function and comments
57