York YCUL0055EE - Checking Inputs and Outputs; TABLE 28 - Outdoor Air Sensor Temperature;Voltage;Correlation

JOHNSON CONTROLS
151
SECTION 9 – SERVICE AND TROUBLESHOOTING
Form 150.63-NM9
Issue date: 5/20/2021
9
Checking inputs and outputs
Digital inputs
See the unit wiring diagram. All digital inputs are con-
nected to J13-1 of the I/O board. The term “digital”
refers to two states – either ON or OFF. As an example,
when the flow switch is closed, 30 VDC will be ap-
plied to J13, pin 5 (J13-5) of the I/O board. If the flow
switch is open, 0 VDC will then be present at J13-5.
Pin 1 of J13 is an unregulated 30 VDC source used
to supply the DC voltage to the various user contacts,
unit switch, flow switch, etc. This DC source is factory
wired to CTB1, terminal 13. Any switch or contact used
as a digital input would be connected to this terminal,
with the other end connecting to its respective digital
input on the microboard. Any time a switch or contact
is closed, 30 VDC would be applied to that particular
digital input. Any time a switch or contact is open, 0
VDC would be applied to that particular digital input.
Typically, voltages of 24 VDC to 36 VDC could be
measured for the DC voltage on the digital inputs. This
voltage is in reference to ground. The unit case should
be sufficient as a reference point when measuring digi-
tal input voltages.
Analog Inputs – Temperature
See the unit wiring diagram. Temperature inputs are
connected to the microboard on plug J6. These analog
inputs represent varying DC signals corresponding to
varying temperatures. All voltages are in reference to
the unit case (ground). The following are the connec-
tions for the temperature sensing inputs:
Outside Air Sensor
J6-6 = +5 VDC regulated supply to sensor.
J6-9 = VDC input signal to the microboard.
See Table 28 for voltage readings that
correspond to specific outdoor temperatures.
J6-3 = drain (shield connection = 0 VDC) Return
Table 28 - Outdoor Air Sensor Temperature/Voltage/
Correlation
TEMP °F
VOLTAGE
(SIGNAL INPUT
TO RETURN)
TEMP °C
0 0.7 -18
5 0.8 -15
10 0.9 -12
15 1.0 -9
20 1.1 -7
25 1.2 -4
30 1.4 -1
35 1.5 2
40 1.7 4
45 1.8 7
50 2.0 10
55 2.2 13
60 2.3 16
65 2.5 18
70 2.6 21
75 2.8 24
80 2.9 27
85 3.1 29
90 3.2 32
95 3.4 35
100 3.5 38
105 3.6 41
110 3.7 43
115 3.8 46
120 3.9 49
125 4.0 52
130 4.1 54