![Schweitzer Engineering Laboratories SEL-321 Instruction Manual Download Page 104](http://html.mh-extra.com/html/schweitzer-engineering-laboratories/sel-321/sel-321_instruction-manual_1216711104.webp)
2-80
Specifications
Date Code 20011026
SEL-321/321-1 Instruction Manual
Figure 2.49: Ground and Phase Distance Speed Curves
T
IME
-O
VERCURRENT
C
URVE
E
QUATIONS
Both US and IEC time-overcurrent curves are provided in the SEL-321 Relay. Use the SET
command to select the curve characteristics you desire. Refer to
Section 3: Communications
for a complete description of the use of the SET command and selection of time-overcurrent
characteristics.
These time curve equations are valid for all time-overcurrent elements. Plots showing operating
time versus multiples of pickup current are shown on the following pages. The equations and
curves apply while the product of the multiples of pickup and pickup setting is less than 32
⋅
I
nominal
amps, secondary.
Summary of Contents for SEL-321
Page 4: ......
Page 10: ......
Page 12: ......
Page 162: ......
Page 171: ...Date Code 20011026 Event Reporting 4 9 SEL 321 321 1 Instruction Manual ...
Page 263: ...SEL DIRECTION AND POLARITY CHECK FORM ...
Page 264: ......
Page 265: ...SEL DIRECTION AND POLARITY CHECK FORM ...
Page 266: ......
Page 270: ......
Page 358: ......
Page 360: ......
Page 362: ......
Page 366: ......
Page 370: ......
Page 390: ......