York MAXE OPTIVIEW YK Service Instructions Manual page 127

When the OPEN or CLOSE key is pressed, the valve
position will be increased or decreased by 5% to a max-
i mum of 100% or minimum of 0%. Each time either key
is pressed, the LED in the respective key will illuminate
for 2 seconds. The Hot Gas Bypass Control Mode will
display "Manual".
ANALOG I/O BOARD
The optional Analog I/O Board mounts inside the Con-
trol Center, on the upper right hand side of the Control
Center. It receives the Hot gas valve positioning com-
mand from the Microboard over the RS-485 serial
com mu ni ca tions link and converts this digital value to
a 2-10VDC analog control signal that is applied to the
valve actuator. The scaling of this signal is as described
above. Valve position is displayed on the HOT GAS
BYPASS Screen as 0% (closed) to 100% (fully open).
Positions between these extremes are linearly scaled.
The Pre-rotation Vanes (PRV) potentiometer (2.5K
Ohms) is connected to P1, providing a 0 to 5VDC volt-
age from a +12VDC source that represents PRV positon.
Potentiometer rotation is limited to 37 degrees. PRV
YORK INTERNATIONAL
position is displayed on the COMPRESSOR Screen
as 0 (closed) to 100% (fully open). Positions between
these extremes are linearly scaled. To assure position
ac cu ra cy, a calibration procedure must be performed as
de tailed in the "System Calibration, Service Setpoints
and Reset Procedures" section of this book. The PRV
po si tion is transmitted to the Microboard via the RS-485
serial communications link.
The Analog I/O Board must be confi gured properly for
the Hot Gas control. The on-board Program Jumpers
must be confi gured as follows:
JUMPER
J1
J26
J39
There must be a 499 Ohm, 1%, ½ watt resistor con-
nect ed between P10-2 and P10-5. This converts the
normal 4-20mA Analog I/O Board output to a 2-10VDC
valve positioning output, required by the Hot Gas valve
actuator.
FORM 160.54-M1(503)
POSITION
Pins 2 & 3
Pins 2 & 3
Pins 1 & 2
20
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