York YCAL Series - CHECKING INPUTS AND OUTPUTS; Digital Inputs; Analog Inputs - Temperature

FORM 150.66-NM3
ISSUE DATE: 09/25/2020
149
JOHNSON CONTROLS
SECTION 9 - SERVICE AND TROUBLESHOOTING
9
CHECKING INPUTS AND OUTPUTS
Digital Inputs
Refer to the unit wiring diagram. All digital inputs are
connected to J13 of the microboard. The term “digital”
refers to two states – either on or o. As an example,
when the ow switch is closed, 30 volts DC will be
applied to J13, pin 5 (J13-5) of the microboard. If the
ow switch is open, 0 volts DC 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, ow switch, etc. This DC source is fac-
tory wired to CTB1, terminal 13. Any switch or con-
tact used as a digital input would be connected to this
terminal, with the other end connecting to its respec-
tive 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, 0VDC would be applied to that particular digital
input.
Typically, voltages as high as 34 VDC could be mea-
sured for the DC voltage on the digital inputs. This
voltage is in reference to ground. The unit case should
be sucient as a reference point when measuring digi-
tal input voltages.
Analog Inputs – Temperature
Refer to the unit wiring diagram. Temperature inputs
are connected to the microboard on plug J6. These ana-
log inputs represent varying DC signals corresponding
to varying temperatures. All voltages are in reference
to the unit case (ground). 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 30 for voltage readings that corre
spond to specic outdoor temperatures.
J6-3 = drain (shield connection = 0 VDC) Return
TABLE 30 – OUTDOOR AIR SENSOR
TEMPERATURE/VOLTAGE/
RESISTANCE 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