Smart Equipment™ Unit Control Board; Unit Control Board - York ZR Series Installation Manual

5167531-YIM-J-1019
Smart Equipment™ unit control board
W1
W2
Y1
G
A
Y2
OCC
X
R
SD-24
C
N
M
Figure 35: Unit control board
The following tables describe the details of the UCB, see Figure 35 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
R
24 VAC hot for thermostat switching and power
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
60
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
Johnson Controls Ducted Systems
P Q
R