GE Multilin 489 Instruction Manual page 184

Note
5–74
Courtesy of NationalSwitchgear.com
100000
10000
1000
100
10
1.00
0.10 1.00
FIGURE 5–15: 489 Standard Overload Curves
Above 8.0 × Pickup, the trip time for 8.0 is used. This prevents the overload curve from
acting as an instantaneous element.
The standard overload curves equation is:
Time to Trip
--------------------------------------------------------------------------------------------------------------------------------------------- -
=
0.02530337
x15
x1
10
MULTIPLE OF FULL LOAD AMPS
×
Curve Multiplier 2.2116623
2
( Pickup 1 )
×
0.05054758
–
+
489 GENERATOR MANAGEMENT RELAY – INSTRUCTION MANUAL
CHAPTER 5: SETPOINTS
100 1000
806804A5.CDR
(EQ 5.31)
( Pickup 1 )
×
–