Changing Setpoints; Introduction - GE 469 Instruction Manual

469

Changing Setpoints

Motor Management Relay
Changing Setpoints

Introduction

There are several classes of setpoints, each distinguished by the way their values
are displayed and edited.
The relay's menu is arranged in a tree structure. Each setting in the menu is
referred to as a setpoint, and each setpoint in the menu may be accessed as
described in the previous section.
The settings are arranged in pages with each page containing related settings; for
example, all the Short Circuit Trip settings are contained within the same page. As
previously explained, the top menu page of each setting group describes the
settings contained within that page. Pressing the MESSAGE keys allows the user to
move between these top menus.
All of the 469 settings fall into one of following categories: device settings, system
settings, digital input settings, output relay settings, thermal model settings,
current element settings, motor starting settings, RTD temperatures settings,
voltage element settings, power element settings, monitoring settings, analog
input/output settings, two speed motor settings, and testing settings.
IMPORTANT NOTE: Settings are stored and used by the relay immediately
after they are entered. As such, caution must be exercised when entering
settings while the relay is in service. Modifying or storing protection
NOTE
settings is not recommended when the relay is in service since any
incompatibility or lack of coordination with other previously saved settings
may cause unwanted operations.
Now that we have become more familiar with maneuvering through messages, we
can learn how to edit the values used by all setpoint classes.
Hardware and passcode security features are designed to provide protection against
unauthorized setpoint changes. Since we will be programming new setpoints using
the front panel keys, a hardware jumper must be installed across the setpoint
access terminals (C1 and C2) on the back of the relay case. Attempts to enter a new
setpoint without this electrical connection will result in an error message.
The jumper does not restrict setpoint access via serial communications. The relay
has a programmable passcode setpoint, which may be used to disallow setpoint
changes from both the front panel and the serial communications ports. This
passcode consists of up to eight (8) alphanumeric characters.
The factory default passcode is "0". When this specific value is programmed into the
relay it has the effect of removing all setpoint modification restrictions. Therefore,
only the setpoint access jumper can be used to restrict setpoint access via the front
panel and there are no restrictions via the communications ports.
When the passcode is programmed to any other value, setpoint access is restricted
for the front panel and all communications ports. Access is not permitted until the
passcode is entered via the keypad or is programmed into a specific register (via
communications). Note that enabling setpoint access on one interface does not
automatically enable access for any of the other interfaces (i.e., the passcode must
be explicitly set in the relay via the interface from which access is desired).
A front panel command can disable setpoint access once all modifications are
complete. For the communications ports, writing an invalid passcode into the
register previously used to enable setpoint access disables access. In addition,
setpoint access is automatically disabled on an interface if no activity is detected for
thirty minutes.
The EnerVista 469 Setup software incorporates a facility for programming the
relay's passcode as well as enabling and disabling setpoint access. For example,
when an attempt is made to modify a setpoint but access is restricted, the software
will prompt the user to enter the passcode and send it to the relay before the
setpoint is actually written to the relay. If a SCADA system is used for relay
programming, it is the programmer's responsibility to incorporate appropriate
security for the application.
GE Multilin
1–6
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