York YK-EP B Operation & Maintenance Manual page 37

FORM 160.87-OM1
ISSUE DATE: 8/24/2018
This read box displays the remaining seconds until PID
control.
Level Control Valve Command
Indicates the valve command as a percentage of full
open. It is only displayed when the valve control meth-
od is analog.
PROGRAMMABLE
Level Setpoint
Access Level Required: SERVICE
Displays the setpoint to which the refrigerant level is
being controlled. (Adjustable 20 to 80%; default 50%).
Startup Position
Access Level Required: SERVICE
Sets the starting position of the refrigerant valve to al-
low the system to match the load quicker. (Adjustable
0 to 100%; default 50%).
Startup Delay
The amount of time the refrigerant level valve PID
waits after start before it starts controlling the valve
position. This allows the system to stabilize before
making valve position changes. (Set at 15 seconds but
is adjustable with an Admin password).
Ramp Time
Access Level Required: ADMIN
After the chiller has been running for the level con-
trol startup delay time, if the refrigerant level is less
than the Level Setpoint, a linearly increasing ramp is
applied to the Level Setpoint. This ramp allows the
level to go from the present level to the programmed
Level Setpoint over a period of time programmed as
the Ramp Up Time. This setpoint can only be changed
with ADMIN level access.(1 to 5 minutes; default 1).
Manual Increment
Access Level Required: ADMIN
This sets the percentage the refrigerant valve will man-
ually be driven with each press of the Open or Close
buttons. (0.1 to 10%; default 1.0%).
Open
Pressing this button will set the Condenser Level Con-
trol Valve Mode to Manual, if it had been in Auto. It
will increase the current Condenser Level Control
Valve Command by an amount equal to the Manual In-
crement, with a maximum of 100.0%.
JOHNSON CONTROLS
SECTION 2 - OPTIVIEW CONTROL CENTER INTRODUCTION
Close
Pressing this button will set the Condenser Level Con-
trol Valve Mode to Manual if it had been in Auto and
will decrease the current Condenser Level Control
Valve Command by an amount equal to the Manual In-
crement, with a minimum of 0.0%.
Set
Access Level Required: SERVICE
Pressing this button will open a dialog box where the
user can manually enter a valve command. Once a legiti-
mate value has been entered and the Enter key pressed,
the Condenser Level Control Valve Mode will be set
to Manual if it had been in Auto. The Condenser Level
Control Valve Command will be set to the entered value.
Change Setpoints
Access Level Required: ADMIN
Provide ability to change the High Threshold, Low
Threshold and three PID gain settings.
High Threshold
Access Level Required: ADMIN
Sets the high limit for the Subcooler Effectiveness
Warning. (Adjustable 0 to 100%; default 50%).
Low Threshold
Access Level Required: ADMIN
Sets the low limit for the Subcooler Effectiveness
Warning. (Adjustable 0 to 100%; default 50%).
KP
Access Level Required: ADMIN
Sets the Proportional value of the PID control loop.
(Adjustable 0.1 to 15; default 1.0).
Ti
Access Level Required: ADMIN
Sets the Integral value of the PID control loop. (Ad-
justable 0.1 to 200; default 100).
Td
Access Level Required: ADMIN
Sets the Derivative value of the PID control loop. (Ad-
justable 0.0 to 200; default 0.0).
NAVIGATION
Home
Access Level Required: VIEW
Returns user to HOME Screen.
Condenser
Access Level Required: VIEW
Returns user to CONDENSER Screen.
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