3.15
Date Code 20171006 Instruction Manual SEL-400 Series Relays
Basic Relay Operations
Making Simple Settings Changes
For more information on the front-panel screen presentations and the items in the
RELAY STATUS screens, see Relay Status on page 4.29.
Making Simple Settings Changes
Isolate the relay trip circuits while
changing settings. When changing set-
tings for multiple classes, it is possible
to be in an intermediate state that will
cause an unexpected trip.
The relay settings structure makes setting the relay easy and efficient. Settings
are grouped logically, and relay elements that are not used in your selected pro-
tection scheme are hidden. QuickSet uses a similar method to focus your atten-
tion on the active settings. Unused relay elements and inactive settings are
dimmed (grayed) in the QuickSet menus. See Section 2: PC Software for more
information on QuickSet.
Settings Structure
SEL-400 series relays use a settings structure that assigns each relay setting to a
specific location based on the setting type. A top-down organization allocates
relay settings into these layers:
➤ Class
➤ Instance
➤ Category
➤ Setting
Examine Figure 3.11 to understand the settings structure in a typical relay. The
top layer of the settings structure contains classes and instances. Class is the pri-
mary sort level; all classes have at least one instance, and some classes have mul-
tiple instances. Settings classes and related instances for the SEL-451, which are
typical of SEL-400 series relays, are listed in Table 3.4. See Section 8: Settings of
the product-specific instruction manual for details on the classes and instances
for a given relay.
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