Manual 37137B
ESDR 4 - Current Differential Protection Relay
Chapter 5.
Display and Operating Elements
The foil covering of the front panel consists of coated plastic. All keys comprise of touch sensitive membrane
elements. The display is a Liquid Crystal display (LC-display), comprised of two rows of text that are 16 charac-
ters each and indirectly illuminated (green). The contrast of the display can be continuously adjusted by means of
a rotary potentiometer on the left hand side.
Monitoring
Differential Current
Protection
ON
Alarm
I
s
I
a
I
b
+
2
=
I
a
I
b
I
d =
Protected
Object
I
a
I
b
[ ]
Operating and Alarm Messages
L1
L2 L3
Release
Variable Release Characteristic
X
Y
10%
I
d
N
I
I
s
N
I
Lock
I
s
I
d
1
2
4
12
13
14
5
3
Figure 5-1: Front panel
Short Description of LEDs and Buttons
≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡
LEDs
No.. Designation
Function
1
I
S
Restraint
current
2
I
d
Differential
current
3
Monitoring ON
Monitoring activated
4
Alarm
Alarm
initiated
Buttons
No. Designation Function
12
Message
↓
Scroll
message
12
Select
Confirm
selection
13
Display
↓
Scroll
display
13
Digit
↑
Increase
digit
14
Clear
Clear (Reset) of fault message
14
Cursor
→
Move cursor one position to the right
Miscellaneous
No. Designation
Function
5
LC-Display
LC-Display
Page 18/35
© Woodward
