Manual 37138C
ESDR 4T - Current Differential Protection Relay
Page 20/46
© Woodward
Chapter 5.
Display and Operating Elements
The foil covering of the front panel consists of coated plastic. All keys are comprised of touch sensitive mem-
brane elements. The display is a Liquid Crystal display (LC-display), comprised of two rows of text that are 16
characters each and are 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
