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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
its respective binary input on the microboard. Anytime 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 refer-
ence to ground. The unit case should be sufficient 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 analog
inputs represent varying dc signals corresponding to vary-
ing temperatures. All voltages are in reference to the
unit case (ground). Following are the connections for the
temperature sensing inputs:
YORK INTERNATIONAL
Outside Air Sensor (Refer to Table 29)
J6-4 = +5 VDC regulated supply to sensor.
J6-7 = VDC input signal to the microboard. See Table
29 for voltage readings that correspond to spe-
cific outdoor temperatures.
J6-1 = drain (shield connection = 0 VDC)
Discharge Air Temperature Sensor
(Refer to Table 30)
J6-6 = +5 VDC regulated supply to sensor.
J6-9 = VDC input signal to the microboard. See Table
30 for voltage readings that correspond to
specific discharge temperatures.
J6-3 = drain (shield connection = 0 VDC)
Suction Temperature Sensor - System 1
(Refer to Table 31)
J5-7 = +5 VDC regulated supply to sensor.
J5-12= VDC input signal to the microboard. See Table
31 for voltage readings that correspond to spe-
cific suction temperatures.
J5-1 = drain (shield connection = 0 VDC)
Suction Temperature Sensor - System 2
(Refer to Table 31)
J5-8 = +5 VDC regulated supply to sensor.
J5-13 = VDC input signal to the microboard. See Table
31 for voltage readings that correspond to
specific suction temperatures.
J5-2 = drain (shield connection = 0 VDC)
FORM 150.63-NM2
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