Smart Equipment™ Unit Control Board; Unit Control Board - Johnson Controls ZF Series Installation Manual

Smart Equipment™ unit control board
W1
W2
Y1
G
A
Y2
OCC
X
R
SD-24
C
N
M
Figure 34: Unit control board
The following tables describe the details of the UCB, see Figure 33 for the connection locations.
Smart Equipment™ UCB - thermostat connection strip
Location Label
W1 1st stage heating request, 24 VAC input switched from R
W2 2nd stage heating request, 24 VAC input switched from R
Y1 1st stage cooling request, 24 VAC input switched from R
Y2 2nd stage cooling request, 24 VAC input switched from R
Continuous indoor blower request, 24 VAC input switched
G
from R
A
OCC Occupancy request, 24 VAC input switched from R
X Hard lockout indicator, 24 volt output to a light thermostat LED
24 VAC hot for thermostat switching and power
R
If field-added external accessories for unit shutdown are used,
SD-24 24 VAC hot out for smoke detector, condensate overflow and/
or user shutdown relay switching in series
C 24 VAC common for thermostat power
Johnson Controls Ducted Systems
B C
L
K J
Description
D
O
E
F
G
I H
Function and comments
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 thermostat
connection strip SD-24 and R
5566018-YIM-B-1018
P Q
R
65