Overview Of Interface - York YD Mod D Operation Manual

The Start/Stop control is operated using a three-position rocker switch. When toggled all the way to
the right, it is in the STOP/RESET position. When in the middle position, this is the RUN state. When
toggled to the left-most position, it is in the START state. Each state is described in detail as follows:
STOP / RESET
When in this position, the chiller does not run under any condition. The switch must be placed in
this state following a Safety shutdown before the chiller is allowed to restart. This guarantees that
manual intervention has taken place and the shutdown has been acknowledged.
START
The switch can only remain in this position when being acted upon by a manual force. After
releasing the switch, it automatically reverts to the RUN position. Generally, this state only occurs
momentarily as the operator attempts to locally start the unit. Once this position has been sensed,
if all fault conditions are cleared, the unit will enter the system prelube (start sequence).
RUN
When in this position, the chiller is able to operate. The switch spring-returns to this state after
it has been toggled to the START position. When in this state, the chiller is allowed to function
normally, and will also allow the chiller to automatically restart following a Cycling shutdown. The
switch must be in this state to receive a valid remote start signal when operating under a remote
control source.

Overview of interface

The new graphical display on each control panel allows a wide variety of information to be
presented to the user. Each screen description in this document will begin with a section entitled
Overview which will describe the graphical elements on the screen and give a short summary of
the functions available. Each element on the screen will then be categorized into three distinct
groups: Display Only, Programmable, and Navigation. Below is a short description of what types of
information are included in these groups.
The Programmable values and Navigation commands are also subject to access level restrictions
as described below. For each of these elements, an indication is given to show the minimum access
level required to program the value or navigate to the subscreen.
Display only
Values in this group are read-only parameters of information about the chiller operation. This
type of information may be represented by a numerical value, a text string, or an LED image. For
numerical values, if the monitored parameter is above the normal operating range, the high limit
value will be displayed along with the '>' symbol; if it is below the normal operating range, the low
limit value will be displayed along with the '<' symbol. In some cases, the value may be rendered
invalid by other conditions and the display will use X's to indicate this.
Programmable
Values in this group are available for change by the user. In order to program any setpoints
on the system, the user must first be logged in with the appropriate access level. Each of the
programmable values requires a specific Access Level which will be indicated beside the specified
value. All of the programmable controls in the system fall into one of these categories:
Access level
In order to program any setpoints on the system, the user must first login with an appropriate
access level. When power is applied to the chiller, the system begins with an Access Level of
VIEW. This will allow the user to navigate to most screens and observe the values displayed there.
However, the user will not be allowed to change any values. To change any values, the user must
return to the Home Screen (shown by default when power is applied to the system), and use the
Model YD Mod D with OptiView Control Center 25