York YCAL0014E Series, Installation Operation & Maintenance

Page: 133 / 212

JOHNSON CONTROLS
133
FORM 150.62-NM8 (1020)
4
Analog Inputs – Pressure
Refer to the unit wiring diagram. Pressure inputs are
connected to the I/O Board on plugs J7 and J9. These
analog inputs represent varying dc signals corresponding
to varying pressures. All voltages are in reference to the
unit case (ground).
System 1 discharge and suction pressures will be
connected to J7 of the I/O Board. System 2 discharge
and suction pressure transducers will be connected to
J9 of the I/O Board.
The discharge transducers are optional on all units except
the YCAL0090 through YCAL0134. If the discharge
transducers are not installed, no connections are made
to the I/O Board and the discharge pressure readout on
the display would be zero.
The suction pressure transducers are optional on
YCAL0014 through YCAL0060. If the suction
transducers are not installed, a mechanical low pressure
switch will be installed in its place, and the suction
pressure readout on the display will be 0 psig when the
low pressure switch is open, and 200 psig (13.79 barg)
when the low pressure switch is closed.
The discharge transducers have a range from 0 to 400
psig. The output will be linear from .5VDC to 4.5VDC
over the 400 psig (27.5 barg) range. Following is the
formula that can be used to verify the voltage output of
the transducer. All voltage reading are in reference to
ground (unit case).
V = (Pressure in psig x .01) + .5
or
V = (Pressure in barg x .145) + .5
where V = dc voltage output
Pressure = pressure sensed by transducer
The I/O Board connections for the Discharge
Transducers:
System 1 Discharge Transducer
J7-6 = +5VDC regulated supply to transducer.
J7-11 = VDC input signal to the I/O Board.
See
the formula above for voltage readings
that correspond to specific discharge
pressures.
J7-7 = +5VDC return
J7-2 = drain (shield connection = 0VDC)
System 2 Discharge Transducer
J9-6 = +5VDC regulated supply to transducer.
J9-11 = VDC input signal to the I/O Board.
See the
formula above for voltage readings that correspond
to specific discharge pressures.
J9-7 = +5VDC return
J9-2 = drain (shield connection = 0VDC)
The suction transducers have a range from 0 to 200 psig
(13.79 barg). The output will be linear from .5VDC to
4.5VDC over the 200 psig (13.79 barg) range. Following
is a formula that can be used to verify the voltage output
of the transducer. All voltage reading are in reference to
ground (unit case).
V = (Pressure in psig x .02) + .5
or
V = (Pressure in barg x .29) + .5
Where V = dc voltage input to microprocessor
Pressure = pressure sensed by transducer
Following are the I/O Board connections for the Suction
Transducer:
System 1 Suction Transducer
J7-5 = +5VDC regulated supply to transducer.
J7-10 = VDC input signal to the I/O Board. (
See
the formula above for voltage readings that
correspond to specific suction pressures.)
J7-9 = +5VDC return
J7-1 = drain (shield connection = 0VDC)
System 2 Suction Transducer
J9-5 = +5VDC regulated supply to transducer.
J9-10 = VDC input signal to the I/O Board.
(See
the formula above for voltage readings that
correspond to specific suction pressures.)
J9-9 = +5VDC return
J9-1 = drain (shield connection = 0VDC)
If the optional Suction Transducer is not used on the
YCAL0014 through YCAL0060, a Low Pressure switch
will be used. Following are the I/O Board connections
for the Low Pressure switch.