Ground Directional - GE Multilin 489 Instruction Manual
Generator management relay
Hide thumbs
Also See for Multilin 489:
- Instruction manual (306 pages) ,
- Communications manual (78 pages) ,
- Instruction manual (259 pages)
Table of Contents
Advertisement
5.6.9
Ground Directional
1 GROUND
DIRECTIONAL
5–40
Courtesy of NationalSwitchgear.com
The differential element for phase A will operate when:
I
where the following hold:
I
operate
I
restraint
k
characteristic slope of the differential element in percent
=
k
Slope1 if I
<
2
=
R
I
= phase current measured at the output CT
A
I
= phase current measured at the neutral end CT
a
Differential elements for phase B and phase C operate in the same manner.
1
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0
0
0.5
1
PATH: SETPOINTS
S5 CURRENT ELEM.
[ ]
SUPERVISE WITH
DIGITAL INPUTS: Yes
GROUND DIRECTIONAL
MESSAGE
MTA: 0°
GROUND DIRECTIONAL
MESSAGE
ALARM: Off
ASSIGN ALARM
MESSAGE
RELAYS (2-5): ---5
GROUND DIR. ALARM
MESSAGE
PICKUP: 0.05 x CT
>
k I
×
operate
restraint
I
I
operate current
=
+
=
A
a
I
I
+
A
a
--------------------
restraint current
=
=
2
×
CT
; k
Slope2 if I
≥
2
×
=
R
OPERATE
REGION
Slope 1 = 10%
1.5
2
2.5
3
I
(multiples of CT)
RESTRAINT
FIGURE 5–4: Differential Elements
GROUND DIRECTIONAL
Range: Yes, No.
Range: 0°, 90°, 180°, 270°
Range: Off, Latched, Unlatched
Range: Any combination of Relays 2 to
Range: 0.05 to 20.00 × CT in steps of
489 GENERATOR MANAGEMENT RELAY – INSTRUCTION MANUAL
CHAPTER 5: SETPOINTS
(EQ 5.12)
(EQ 5.13)
(EQ 5.14)
(EQ 5.15)
CT
(EQ 5.16)
(EQ 5.17)
Slope 2 = 20%
Minimum Pickup = 0.10 x CT
4.5
5
3.5
4
808790A2.CDR
MTA = Maximum Torque Angle
5
0.01
Advertisement
Table of Contents
