York MILLENNIUM YCUL0016SC, Assembly, Installation, Operation & Maintenance

Page: 134 / 172

YORK INTERNATIONAL
134
CHECKING INPUTS AND OUTPUTS
Binary Inputs
Refer to the unit wiring diagram. All binary inputs are
connected to J9 of the microboard. The term “binary”
refers to two states - either on or off. As an example,
when the air flow switch is closed, 30 volts DC will be
applied to J9, pin 5 (J9-5) of the microboard. If the air
flow switch is open, 0 volts DC will then be present at
J9-5.
Pin 1 of J9 is an unregulated 30 VDC that is the DC
voltage source used to supply the DC voltage to the
various contacts, unit switch, air flow switch, etc. This
DC source is factory wired to CTB1, terminal 13. Any
switch or contact used as a binary input would be con-
nected to this terminal, with the other end connecting
to it’s respective binary input on the microboard. Any-
time a switch or contact is closed, 30 VDC would be
applied to that particular binary input. Anytime a switch
or contact is open, 0 VDC would be applied to that
particular binary input.
Typically, as high as 34 VDC could be measured for
the DC voltage on the binary inputs. This voltage is
in reference to ground. The unit case should be suffi-
cient as a reference point when measuring binary 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
J6-4 = +5 VDC regulated supply to sensor.
J6-7 = VDC input signal to the microboard. See
Table 29 for voltage readings that corre-
spond to specific outdoor temperatures.
J6-1 = Drain (shield connection = 0 VDC)
TEMP °F VOLTAGE RESISTANCE TEMP C°
0 0.7 85398 -18
5 0.8 72950 -15
10 0.9 62495 -12
15 1.0 53685 -9
20 1.1 46240 -7
25 1.2 39929 -4
30 1.4 34565 -1
35 1.5 29998 2
40 1.7 26099 4
45 1.8 22673 7
50 2.0 19900 10
55 2.2 17453 13
60 2.3 15309 16
65 2.5 13472 18
70 2.6 11881 21
75 2.8 10501 24
80 2.9 9298 27
85 3.1 8250 29
90 3.2 7332 32
95 3.4 6530 35
100 3.5 5827 38
105 3.6 5209 41
110 3.7 4665 43
115 3.8 4184 46
120 3.9 3759 49
125 4.0 3382 52
130 4.1 3048 54
TABLE 29 – OUTDOOR AIR SENSOR
TEMPERATURE/VOLTAGE/
RESISTANCE CORRELATION
Control Service and Troubleshooting