Changing Setpoints; Introduction - GE Multilin 489 Instruction Manual

CHAPTER 1: GETTING STARTED
1.3

Changing Setpoints

1.3.1

Introduction

Note
489 GENERATOR MANAGEMENT RELAY – INSTRUCTION MANUAL
Courtesy of NationalSwitchgear.com
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 Phase Overcurrent 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
these top menus.
All of the 489 settings fall into one of following categories: device settings, system settings,
digital input settings, output relay settings, current element settings, voltage element
settings, power element settings, RTD temperature settings, thermal model settings,
monitoring settings, analog input/output 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 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).
keys allows the user to move between
MESSAGE
1–9